JBCOSE-MAX 1000 & 100

Indications

• Dry eye conditions
• Tear deficiency
• Keratoconjunctivitis sicca

Dosage

Children: Apply as required, typically in the form of eye drops.

Adults: Apply as required, typically in the form of eye drops.

Mechanism of action

Hypromellose acts by forming a viscous gel upon contact with the ocular surface, which helps to retain moisture and protect against irritants. This gel-like property enhances the stability of the tear film and reduces evaporation, thereby alleviating symptoms associated with dry eye conditions.

Pharmacodynamics

The pharmacodynamic effects of hypromellose are primarily related to its ability to mimic natural tears, providing lubrication to the ocular surface. This lubrication reduces friction during blinking and maintains corneal hydration, which is critical for ocular comfort and health. Its high viscosity also contributes to prolonged retention time on the eye surface.

Pharmacokinetics

Hypromellose is administered topically as eye drops and is not significantly absorbed systemically. The retention time of hypromellose on the ocular surface is enhanced due to its viscosity, allowing for extended relief of dry eye symptoms. The elimination of hypromellose occurs primarily through drainage from the eye and dilution by the natural tear fluid.

Adverse effects

• Temporary visual disturbance
• Eye irritation

Precautions

• Should not be used during contact lens wear
• Use with caution in patients with known hypersensitivity to any component of the formulation

Pregnancy

Hypromellose is generally considered safe for use during pregnancy. However, it should be used only if clearly needed and after consulting a healthcare provider.

Breast-feeding

Hypromellose is unlikely to affect breastfed infants when used as directed, but consultation with a healthcare provider is advisable.

Storage

Store in a cool, dry place away from direct sunlight. Once opened, use within a specified period as indicated on the packaging.

Formulations

• {'name': 'Teardew', 'concentration': '0.3%', 'form': 'eye drops', 'volume': '10 ml'}
• {'name': 'Xailin Hydrate', 'concentration': '0.3%', 'form': 'eye drops', 'volume': '10 ml'}
• {'name': 'AacuLose', 'concentration': '0.3%', 'form': 'eye drops', 'volume': '10 ml'}
• {'name': 'Artelac', 'concentration': '0.32%', 'form': 'eye drops', 'volume': '10 ml'}
• {'name': 'Lacrilube', 'concentration': '2 mg/g', 'form': 'eye ointment', 'volume': '3.5 g'}
• {'name': 'Celluvisc', 'concentration': '1%', 'form': 'eye drops', 'volume': '0.4 ml unit dose'}

Indications

• Type 2 diabetes mellitus
• Gestational diabetes
• Management of pre-existing diabetes in pregnant women

Dosage

Children: For children aged 10 years and older, the usual starting dose is 500 mg taken with food, with gradual increases based on clinical response. Refer to the BNF for Children for specific dosing recommendations.

Adults: The initial dose is usually 500 mg to 1,000 mg taken orally with food, and the dosage may be gradually increased based on glycemic control and tolerance, with a maximum daily dose typically not exceeding 2,000 mg.

Mechanism of action

Metformin decreases hepatic glucose production and increases peripheral glucose utilization. It does not stimulate insulin release from the pancreas, making it antihyperglycemic rather than hypoglycemic. The drug also interacts with SIRT1, a protein involved in bile acid metabolism, contributing to its effects on glucose homeostasis.

Pharmacodynamics

Metformin improves glycemic control in patients with type 2 diabetes by reducing fasting and postprandial plasma glucose levels. It acts by decreasing intestinal absorption of glucose, increasing insulin sensitivity, and enhancing peripheral glucose uptake and utilization, without causing hypoglycemia.

Pharmacokinetics

Metformin is absorbed from the gastrointestinal tract and is excreted unchanged in the urine. It has a half-life of about 6 hours and does not undergo significant metabolism. The drug's pharmacokinetics can be affected by renal function, and caution is advised in patients with renal impairment.

Contra-indications

• Severe renal impairment (creatinine clearance less than 25 mL/minute)
• Acute or chronic metabolic acidosis, including diabetic ketoacidosis
• Hypersensitivity to metformin or any of its components

Adverse effects

• Nausea
• Vomiting
• Diarrhea
• Abdominal pain
• Lactic acidosis (rare)
• Hepatic disorders (rare)
• Oedema (rare)
• Acute generalised exanthematous pustulosis (very rare)
• Thrombocytopenia (very rare)

Interactions

• Angiotensin-converting enzyme inhibitors and angiotensin II receptor antagonists may require monitoring and adjustments
• Antacids containing magnesium and aluminium salts may reduce the absorption of metformin
• Concomitant use with other antihyperglycemic agents requires careful monitoring for hypoglycemia

Precautions

• Caution in patients with hepatic impairment
• Monitor liver function regularly during treatment
• Patients should be advised to discontinue use in the event of significant illness, especially dehydration or infections

Pregnancy

Avoid use during pregnancy. Women planning to become pregnant should discontinue metformin and consult a healthcare provider for safer alternatives.

Breast-feeding

Avoid use during breastfeeding. Metformin is excreted in breast milk, and its effects on a nursing infant are unknown.

Storage

Store in a cool, dry place, below 25°C. Protect from light.

Formulations

• Metformin hydrochloride 500 mg tablets
• Metformin hydrochloride 850 mg tablets
• Metformin hydrochloride 1000 mg tablets

Indications

• Skin disinfection
• Preparation of skin before injections
• Cleansing minor wounds

Dosage

Children: Apply to the skin as required; consult product literature for specific guidance.

Adults: Apply to the skin as required for disinfection.

Mechanism of action

Alcohol exerts its antiseptic effect by denaturing proteins, disrupting cell membranes, and dehydrating microbial cells, leading to cell lysis and death.

Pharmacodynamics

Alcohol has broad-spectrum antimicrobial activity, effective against bacteria, fungi, and viruses. Its efficacy is influenced by concentration, with higher concentrations generally being more effective.

Pharmacokinetics

Alcohol is rapidly absorbed through the skin and mucous membranes. It is metabolized primarily in the liver, with a half-life that varies based on the individual's metabolic rate and the amount consumed.

Contra-indications

• Concomitant use with lithium
• Regular use in neonates
• Patients with severe burns when diathermy has been preceded by application of alcoholic skin disinfectants

Adverse effects

• Eye erythema
• Punctate keratitis
• Cytotoxicity
• Eye discolouration

Interactions

• Increases risk of visual disturbances with antiepileptics
• Increases concentration with methylphenidate
• Increases risk of facial flushing and skin irritation with topical pimecrolimus
• Increases concentration with retinoids
• Increases concentration with acitretin
• Increases risk of facial flushing and skin irritation with topical tacrolimus
• Decreases antidiuretic effect with vasopressin

Precautions

• Avoid regular application to inflamed or broken skin or mucosa
• Avoid broken skin
• Flammable

Pregnancy

Sufficient iodine may be absorbed to affect the fetal thyroid in the second and third trimester.

Breast-feeding

Avoid regular or excessive use.

Storage

Store in a cool, dry place away from heat and direct sunlight.

Formulations

• Betadine 2.5% dry powder spray
• Industrial methylated spirit
• Povidone-Iodine 25 mg per 1 gram

Indications

• Methemoglobinemia
• Urinary tract infections
• Surgical marking
• Treatment of certain types of cyanide poisoning

Dosage

Children: Refer to the BNF for Children for appropriate pediatric dosing information.

Adults: Refer to the relevant clinical guidelines or the BNF for specific dosing recommendations.

Mechanism of action

Methylene blue acts as a reducing agent, converting methemoglobin back to its functional form, hemoglobin. This is primarily achieved through its action as an electron donor, facilitating the reduction of ferric iron (Fe3+) in hemoglobin to ferrous iron (Fe2+), thereby restoring its oxygen-carrying capacity. It also exhibits antimicrobial properties through its ability to generate reactive oxygen species when exposed to light, which can inhibit bacterial growth.

Pharmacodynamics

The pharmacodynamics of methylene blue involve its role in enhancing oxygen delivery in patients suffering from methemoglobinemia. By converting methemoglobin back to hemoglobin, it effectively increases the amount of hemoglobin available for oxygen transport. The drug also shows effects on the vascular system, where it can induce vasodilation and influence blood pressure.

Pharmacokinetics

Methylene blue is rapidly absorbed after intravenous administration, with peak plasma concentrations occurring within 1 to 3 hours. It is extensively distributed in body tissues and fluids, including the liver, kidneys, and lungs. The drug undergoes hepatic metabolism, primarily through the cytochrome P450 system, and is excreted mainly through urine. The half-life ranges from 5 to 24 hours, depending on the dosage and individual patient factors.

Pregnancy

Consult healthcare provider before use, as safety in pregnancy is not established.

Breast-feeding

Consult healthcare provider before use, as safety during breastfeeding is not established.

Storage

Store in a cool, dry place away from direct sunlight.

Indications

• Constipation
• Dietary fiber supplementation
• Irritable bowel syndrome
• Diverticular disease
• Weight management

Dosage

Children: Refer to appropriate guidelines for specific dosage; generally taken with adequate fluid intake.

Adults: Refer to appropriate guidelines for specific dosage; generally taken with adequate fluid intake.

Mechanism of action

Cellulose acts primarily as a bulk-forming laxative. It absorbs water in the intestines, which increases stool bulk and stimulates peristalsis, thus facilitating bowel movements. Additionally, cellulose is not digestible by human enzymes, leading to fermentation by gut bacteria, which may enhance gut health and alter gut microbiota composition.

Pharmacodynamics

Cellulose increases stool weight and frequency of bowel movements. It works by retaining water in the intestines, leading to softer stools and improved passage through the gastrointestinal tract. The bulking effect of cellulose can help alleviate constipation and promote overall digestive health. It may also play a role in cholesterol reduction and glycemic control through its effects on digestion and absorption of nutrients.

Pharmacokinetics

Cellulose is not absorbed into the bloodstream due to its indigestible nature. Instead, it passes through the gastrointestinal tract, where it adds bulk to the stool. Its fermentation by colonic bacteria produces short-chain fatty acids, which may have beneficial effects on colon health. The onset of action for cellulose as a laxative can vary but is generally within 24 to 72 hours after ingestion.

Adverse effects

• Bloating
• Flatulence
• Diarrhea
• Abdominal discomfort

Precautions

• Use with caution in patients with a history of gastrointestinal disorders.
• Monitor for potential allergic reactions in sensitive individuals.

Pregnancy

Cellulose is generally considered safe during pregnancy as it is a non-toxic, indigestible fiber.

Breast-feeding

Cellulose is also considered safe during breastfeeding; it is excreted in breast milk in negligible amounts.

Storage

Store in a cool, dry place away from direct sunlight.

Formulations

• Powder
• Capsules
• Tablets
• Granules

Indications

• Hypovolemic shock
• Severe burns
• Postoperative fluid replacement
• Sepsis
• Trauma management

Dosage

Children: Refer to established guidelines for specific dosing, as it varies based on the type of colloidal solution used and the clinical condition being treated.

Adults: Refer to established guidelines for specific dosing, as it varies based on the type of colloidal solution used and the clinical condition being treated.

Mechanism of action

Colloidal solutions work by maintaining oncotic pressure in the blood, thus helping to retain fluid within the vascular system. This is primarily due to the large molecular weight of the colloidal particles, which cannot easily pass through capillary walls. The presence of colloids in the blood helps to draw water into the circulation, increasing blood volume and improving tissue perfusion.

Pharmacodynamics

The pharmacodynamics of colloidal solutions are centered on their ability to exert osmotic pressure, which helps maintain blood volume and pressure. This effect is particularly important in conditions such as hypovolemia and shock, where fluid replacement is necessary to restore hemodynamic stability. The efficacy of colloidal solutions can vary depending on the type of colloid used, as well as the underlying clinical condition being treated.

Pharmacokinetics

Colloidal solutions are typically administered intravenously and their pharmacokinetics can vary based on the specific formulation. Generally, colloids are distributed throughout the vascular compartment and have a longer duration of action compared to crystalloids, as they remain in circulation longer. The elimination of colloids is primarily through the reticuloendothelial system, where they are metabolized or eliminated by the liver and spleen. Factors such as particle size and composition can influence their distribution and clearance.

Adverse effects

• Allergic reactions
• Injection site reactions
• Nausea
• Vomiting
• Headache
• Fever

Precautions

• Use with caution in patients with known allergies to any component of the formulation
• Monitor for signs of hypersensitivity during administration
• Consider volume overload in patients with cardiac or renal impairment

Pregnancy

The safety of colloidal solutions during pregnancy has not been established. Use only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

It is not known whether colloidal solutions are excreted in human milk. Caution should be exercised when administering to breastfeeding mothers.

Storage

Store at room temperature, protect from light, and do not freeze. Keep out of reach of children.

Formulations

• Colloidal silver
• Colloidal gold
• Colloidal iron
• Other metal colloids

Indications

• Monitoring respiratory function
• Assessment of metabolic status
• Management of respiratory acidosis
• Management of respiratory alkalosis

Dosage

Children: Dosing for interventions related to carbon dioxide levels in pediatric patients should be guided by clinical protocols and the BNF for Children.

Adults: Dosing for interventions related to carbon dioxide levels is typically based on clinical assessment and individual patient needs. Refer to clinical guidelines for specific scenarios.

Mechanism of action

Carbon dioxide acts primarily as a signaling molecule in the body, influencing respiratory drive and blood pH. It is produced during cellular respiration and is a critical component of the bicarbonate buffering system, which helps maintain acid-base homeostasis. Elevated levels of CO2 in the blood stimulate ventilation in the lungs, increasing the rate of gas exchange and facilitating the removal of excess CO2.

Pharmacodynamics

The pharmacodynamic effects of dioxides, particularly carbon dioxide, are closely related to its concentration in the blood. As CO2 levels increase, it leads to respiratory acidosis, which can stimulate the respiratory centers in the brain to increase ventilation. Conversely, low levels of CO2 can cause respiratory alkalosis, potentially leading to decreased respiratory drive. CO2 also plays a role in vasodilation and can affect blood flow and pressure through its influence on smooth muscle tone.

Pharmacokinetics

Carbon dioxide is produced endogenously during metabolic processes and is transported in the bloodstream primarily in three forms: dissolved in plasma, as bicarbonate ions (HCO3-), and bound to hemoglobin. The half-life of CO2 in the bloodstream is very short due to its rapid exchange with alveolar gas in the lungs. The elimination of CO2 occurs through exhalation, making it a dynamic component of respiratory physiology.

Pregnancy

Data on the effects of dioxide during pregnancy are limited. Caution is advised due to potential risks associated with exposure.

Breast-feeding

Limited data are available regarding the excretion of dioxide in human milk. Caution is recommended.

Storage

Store in a cool, dry place, away from direct sunlight and moisture.

Indications

• Antioxidant support
• Anti-inflammatory treatment
• Antimicrobial activity
• Potential adjunct in cancer therapy

Dosage

Children: Refer to specific guidelines or literature for appropriate dosing as it may vary based on the formulation and intended use.

Adults: Refer to specific guidelines or literature for appropriate dosing as it may vary based on the formulation and intended use.

Mechanism of action

Gallate exerts its effects primarily through its antioxidant properties, scavenging free radicals and reducing oxidative stress. It may also modulate various signaling pathways involved in inflammation and cell survival, contributing to its potential therapeutic effects.

Pharmacodynamics

The pharmacodynamics of gallate involve its ability to inhibit lipid peroxidation and protect cellular components from oxidative damage. It may also influence enzymatic activities related to metabolic pathways, enhancing the degradation of glutamate and other compounds. Gallate’s interaction with cellular receptors can lead to downstream effects such as reduced inflammation and altered apoptotic processes.

Pharmacokinetics

Gallate is absorbed in the gastrointestinal tract and undergoes metabolism primarily in the liver. Its bioavailability can be affected by food intake and formulation. The elimination half-life and specific excretion pathways are not well-documented, but it is expected to follow typical patterns for phenolic compounds, with renal excretion of metabolites.

Pregnancy

There is insufficient data on the safety of gallate during pregnancy. It is advisable to avoid use unless potential benefits outweigh risks.

Breast-feeding

Limited data available on the excretion of gallate in human milk. Caution is advised when administering to breastfeeding mothers.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Dosage

Children: Refer to the BNF for Children for appropriate dosing information in paediatric cases, especially in instances of overdose.

Adults: Refer to the BNF for specific dosing information based on clinical circumstances, particularly in cases of overdose.

Mechanism of action

Ethylene glycol is metabolized by alcohol dehydrogenase to glycoaldehyde, which is subsequently converted to glycolic, glyoxylic, and oxalic acids. These metabolites contribute to anion gap metabolic acidosis and are responsible for tissue injury through the formation of insoluble calcium oxalate crystals.

Pharmacodynamics

The toxicity of ethylene glycol arises from its metabolites, particularly glycolic and oxalic acids. These compounds induce metabolic acidosis, lead to renal failure through calcium oxalate crystal deposition in the kidneys, and can cause neurological impairment. The anion gap increases due to the accumulation of these acids, leading to complications such as cardiovascular instability and potential multi-organ failure.

Pharmacokinetics

Ethylene glycol is rapidly absorbed after oral ingestion. It undergoes first-pass metabolism primarily in the liver, where it is converted into its toxic metabolites. The elimination half-life of ethylene glycol varies but is generally prolonged in cases of renal impairment. Renal excretion of metabolites contributes to the duration of toxicity, necessitating prompt medical intervention in cases of overdose.

Adverse effects

• Metabolic acidosis
• Renal failure
• CNS depression
• Hypocalcemia
• Cardiovascular collapse
• Pulmonary edema

Precautions

• Use with caution in patients with renal impairment
• Monitor for signs of metabolic acidosis
• Evaluate electrolyte levels, particularly calcium

Pregnancy

There is limited data on the safety of ethylene glycol in pregnancy. It should only be used if clearly needed.

Breast-feeding

It is unknown if ethylene glycol is excreted in human milk. Caution is advised.

Storage

Store in a tightly closed container at room temperature, away from heat and moisture.

Formulations

• Liquid

Indications

• Anxiety disorders
• Nausea and vomiting
• Allergic conditions
• Preoperative sedation
• Pruritus

Dosage

Children: Refer to the BNF for Children for appropriate dosing recommendations based on age and weight.

Adults: Refer to the BNF for specific dosing guidelines based on the indication and patient characteristics.

Mechanism of action

Hydroxyzine works by antagonizing the H1 histamine receptors, leading to a reduction in the effects of histamine in the body. This action helps alleviate symptoms of allergic reactions and promotes sedation. Additionally, it may exert effects on serotonin and adrenergic receptors, which could contribute to its anxiolytic properties. Hydroxyzine is also involved in various metabolic pathways, including selenium metabolism and the degradation of reactive oxygen species.

Pharmacodynamics

The pharmacodynamic effects of hydroxyzine include sedation, anxiolysis, and reduction of allergic symptoms. Its sedative effects can make it useful in managing anxiety and inducing sleep, while its antihistaminic properties help to relieve symptoms such as itching and rashes associated with allergic reactions. The onset of action is typically within 15 to 30 minutes when taken orally, with peak effects occurring within 1 to 2 hours.

Pharmacokinetics

Hydroxyzine is well absorbed from the gastrointestinal tract, with peak plasma concentrations occurring approximately 2 hours after oral administration. It is extensively metabolized in the liver, with metabolites, including cetirizine, possessing their own therapeutic effects. Hydroxyzine has a half-life of approximately 20 hours, allowing for once or twice daily dosing. It is primarily excreted in the urine, with less than 1% of the unchanged drug found in urine.

Interactions

• hydroxyzine+antiepileptics: Severe (increases risk of overheating and dehydration)
• hydroxyzine+zonisamide: Severe (increases risk of overheating and dehydration)
• hydroxychloroquine+penicillamine: Severe (increases risk of haematological toxicity)
• hydroxychloroquine+agalsidase alfa: Unknown (decreases effects)
• hydroxychloroquine+agalsidase beta: Unknown (decreases exposure)
• hydroxychloroquine+oral cholera vaccine: Unknown (decreases efficacy)
• live vaccines+hydroxy carbamide: Unknown (increases risk of generalised infection (possibly life-threatening))
• lanthanum+hydroxychloroquine: Unknown (decreases absorption)
• macrolides+hydroxychloroquine: Unknown (increases risk of serious cardiovascular adverse effects)
• hydroxychloroquine+remdesivir: Unknown (decreases effects)

Pregnancy

Safety in pregnancy has not been established. Use only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Use with caution. Hydroxychloroquine is excreted in breast milk, and effects on the infant are unknown.

Storage

Store in a cool, dry place, protected from light. Keep out of reach of children.

Formulations

• Tablets
• Oral solution

Indications

• Antiseptic for skin disinfection
• Solvent in pharmaceutical formulations
• Cleaning agent in laboratories and healthcare settings

Dosage

Children: For pediatric use, consult specific guidelines in the BNF for Children, as dosing may vary based on age, weight, and clinical circumstances.

Adults: For skin antisepsis, apply isopropyl alcohol topically in a concentration of 70% to the affected area. Dosage may vary based on clinical indication and setting.

Mechanism of action

Isopropyl alcohol works primarily as an antiseptic by denaturing proteins and disrupting cell membranes of bacteria, viruses, and fungi, leading to cell lysis and death. Its efficacy is enhanced by the presence of water, which facilitates the penetration of the alcohol into microbial cells.

Pharmacodynamics

Isopropyl alcohol exhibits a rapid onset of action against a variety of pathogens, including gram-positive and gram-negative bacteria, fungi, and some viruses. Its antimicrobial activity is concentration-dependent, with higher concentrations generally providing a broader spectrum of activity. It is commonly used in concentrations ranging from 60% to 90%, with 70% being optimal for disinfection due to its ability to penetrate the cell wall effectively.

Pharmacokinetics

Isopropyl alcohol is readily absorbed through the skin and mucous membranes. After absorption, it is metabolized primarily in the liver to acetone, which is then further metabolized and excreted, mostly via urine. The elimination half-life of isopropyl alcohol varies but is typically around 2 to 3 hours. Its effects can be influenced by factors such as dosage, route of exposure, and individual metabolic differences.

Pregnancy

Isopropyl alcohol should be used with caution during pregnancy. It is a category C drug, indicating that risk cannot be ruled out.

Breast-feeding

Caution is advised when using isopropyl alcohol during breastfeeding, as it is not known if it is excreted in human milk.

Storage

Isopropyl alcohol should be stored at room temperature, away from heat and flame. Keep the container tightly closed and in a well-ventilated area.

Formulations

• Isopropyl alcohol 70% solution
• Isopropyl alcohol 99% solution

Indications

• Acute diarrhea
• Chronic diarrhea
• Gastroenteritis
• Toxin absorption

Dosage

Children: Refer to established guidelines for specific dosing, as dosing may vary based on formulation and clinical context.

Adults: Refer to established guidelines for specific dosing, as dosing may vary based on formulation and clinical context.

Mechanism of action

Kaolin acts by adsorbing various substances within the gastrointestinal tract. It binds to toxins, bacteria, and other pathogens, which helps to prevent their absorption into the bloodstream. This action reduces the irritation of the intestinal lining and helps restore normal bowel function.

Pharmacodynamics

The pharmacodynamic effects of kaolin include its ability to absorb and retain moisture, which can help solidify feces. Its adsorbent properties may also contribute to its therapeutic effects in gastrointestinal disturbances. By binding to pathogens and toxins, kaolin may reduce inflammation and irritation in the gut.

Pharmacokinetics

Kaolin is not absorbed systemically when administered orally; it remains in the gastrointestinal tract where it exerts its effects. The elimination of kaolin occurs through fecal excretion. Its local action in the gut allows it to exert therapeutic benefits without significant systemic exposure.

Adverse effects

• Constipation
• Abdominal discomfort
• Nausea
• Vomiting

Precautions

• Use with caution in patients with gastrointestinal obstruction
• Monitor for potential constipation, especially in elderly patients

Pregnancy

Kaolin is generally considered safe during pregnancy, but it should be used under medical supervision.

Breast-feeding

Kaolin is not known to be excreted in breast milk and is considered safe during breastfeeding.

Storage

Store in a cool, dry place away from light. Keep out of reach of children.

Formulations

• Oral suspension
• Powder

Indications

• Vision correction
• Phototherapy for skin conditions (e.g., psoriasis, eczema)
• Treatment of seasonal affective disorder (SAD)
• Circadian rhythm disorders
• Wound healing

Dosage

Children: Light therapy for paediatric patients should be approached with caution and always under professional guidance. Specific dosages will depend on the individual treatment protocol and condition being addressed.

Adults: Dosage of light therapy varies based on the condition being treated and should be tailored to individual needs, typically ranging from 15 minutes to 2 hours of exposure per day depending on the specific treatment protocol.

Mechanism of action

Light affects biological systems primarily through phototransduction, which involves the conversion of light into electrical signals within photoreceptor cells in the retina. This process initiates a cascade of biochemical reactions that ultimately lead to visual perception. In addition, specific wavelengths of light can interact with various biological molecules, triggering cellular responses such as the production of vitamin D through skin exposure to UVB radiation.

Pharmacodynamics

The pharmacodynamic effects of light are highly dependent on its wavelength and intensity. Short-wavelength blue light (around 480 nm) is known to influence circadian rhythms by affecting melatonin secretion. In therapeutic settings, light can modulate biological responses, such as promoting wound healing, reducing inflammation, and alleviating symptoms of seasonal affective disorder (SAD) through bright light therapy.

Pharmacokinetics

Light does not undergo traditional pharmacokinetic processes such as absorption, distribution, metabolism, or excretion. Instead, its effects are immediate and localized, depending on the intensity and duration of exposure. The penetration depth of light varies with wavelength; for example, UV light can penetrate the skin and affect deeper tissues, while visible light primarily affects the surface layers.

Pregnancy

There is limited data on the effects of light exposure during pregnancy. However, excessive exposure to bright light can be harmful to both the mother and the developing fetus.

Breast-feeding

Light exposure is generally considered safe while breastfeeding, but excessive exposure should be avoided to prevent potential harm to the infant.

Storage

Light should be properly controlled and managed in environments where it is used, ensuring that exposure levels are safe and effective.

Indications

• Type 2 diabetes mellitus
• Polycystic ovary syndrome (PCOS)

Dosage

Children: The

Adults: The usual starting dose of metformin for adults is 500 mg taken orally twice a day or 850 mg once daily, with gradual increases based on tolerance and blood glucose levels. The maximum recommended daily dose is 2000-3000 mg, depending on the formulation used.

Mechanism of action

Metformin decreases blood glucose levels by decreasing hepatic glucose production (gluconeogenesis), decreasing intestinal absorption of glucose, and increasing insulin sensitivity, which enhances peripheral glucose uptake and utilization. It is known to inhibit mitochondrial complex I activity, leading to increased AMP:ATP ratios that activate AMP-activated protein kinase (AMPK), a key regulator of glucose metabolism. This activation results in reduced hepatic glucose output and improved cellular glucose uptake.

Pharmacodynamics

Metformin exerts its effects primarily by enhancing insulin sensitivity and reducing glucose production by the liver. Unlike sulfonylureas, which increase insulin secretion, metformin does not cause hyperinsulinemia. Its ability to lower fasting plasma glucose and glycosylated hemoglobin (HbA1c) levels makes it a cornerstone in the management of type 2 diabetes. Clinical studies have shown significant reductions in fasting plasma glucose and HbA1c levels in patients treated with metformin.

Pharmacokinetics

Metformin is absorbed from the gastrointestinal tract, with peak plasma concentrations typically occurring 2-3 hours after ingestion. It has a bioavailability of approximately 50-60% when administered orally. The drug is primarily eliminated unchanged by the kidneys, and its clearance is proportional to renal function. The half-life of metformin is about 6.5 hours. Accumulation may occur in cases of renal impairment, necessitating caution in patients with reduced renal function.

Adverse effects

• Gastrointestinal disturbances (nausea, vomiting, diarrhea)
• Lactic acidosis
• Vitamin B12 deficiency

Interactions

• dolutegravir+metformin: Moderate (increases exposure)
• cimetidine+metformin: Moderate (increases exposure)
• risdiplam+metformin: Moderate (increases concentration)
• vandetanib+metformin: Moderate (increases exposure)
• bictegravir+metformin: Unknown (increases exposure)
• guanfacine+metformin: Unknown (increases concentration)
• mexiletine+metformin: Unknown (affects exposure)
• pitolisant+metformin: Unknown (increases exposure)
• ribociclib+metformin: Unknown (increases exposure)

Precautions

• Renal impairment
• Dehydration
• Excessive alcohol intake

Pregnancy

Metformin is classified as a Category B medication. It is often used during pregnancy for managing gestational diabetes but should be administered under medical supervision.

Breast-feeding

Metformin is excreted in breast milk, but is generally considered safe for use during breastfeeding. Consult with a healthcare provider for specific guidance.

Storage

Store in a cool, dry place, away from direct light. Keep out of reach of children.

Formulations

• Tablets
• Extended-release tablets
• Oral solution

Indications

• Allergic conditions
• Autoimmune diseases
• Asthma and chronic obstructive pulmonary disease (COPD)
• Certain cancers (e.g., leukemia, lymphoma)
• Skin conditions (e.g., dermatitis)
• Inflammatory bowel disease
• Multiple sclerosis exacerbations
• Severe infections requiring immunosuppression

Dosage

Children: Refer to BNF for Children for specific dosing; doses vary significantly based on the child's age, weight, and condition being treated.

Adults: Refer to BNF for specific dosing; typically, initial doses range from 4 to 48 mg depending on the severity of the condition.

Mechanism of action

Methylprednisolone exerts its effects by binding to glucocorticoid receptors, leading to the modulation of gene expression. This interaction influences the transcription of anti-inflammatory proteins while suppressing the expression of pro-inflammatory genes, ultimately resulting in reduced inflammation and immune response.

Pharmacodynamics

The pharmacodynamic effects of methylprednisolone are characterized by its ability to decrease inflammation, suppress the immune response, and affect carbohydrate metabolism. Therapeutic doses lead to various systemic effects, including modification of leukocyte distribution and inhibition of cytokine production.

Pharmacokinetics

Methylprednisolone is well absorbed after oral administration, with a bioavailability of approximately 50%. It has a volume of distribution that reflects extensive tissue binding. The drug is metabolized primarily in the liver through conjugation and reduction, and its metabolites are excreted in urine. The half-life varies based on the route of administration but is generally around 18 to 36 hours.

Adverse effects

• Increased blood pressure
• Hyperglycemia
• Weight gain
• Mood changes
• Insomnia
• Gastrointestinal disturbances
• Increased susceptibility to infections

Interactions

• methylphenidate+apraclonidine: Severe (decreases effects)
• methylthioninium chloride+bupropion: Severe (increases risk of severe hypertension)
• methylphenidate+linezolid: Severe (increases risk of elevated blood pressure)
• rasagiline+methylphenidate: Severe (increases risk of a hypertensive crisis)
• mao-inhibitors+methylphenidate: Severe (increases risk of a hypertensive crisis)
• dronedarone+methylprednisolone: Moderate (increases exposure)
• miconazole+methylprednisolone: Moderate (increases concentration)
• antifungals, azoles+methylprednisolone: Moderate (increases exposure)
• crizotinib+methylprednisolone: Moderate (increases exposure)

Precautions

• Use with caution in patients with hypertension
• Monitor blood glucose levels in diabetic patients
• Consider potential for infection risk due to immunosuppression
• Evaluate for psychiatric effects in susceptible individuals

Pregnancy

Corticosteroids may be used during pregnancy if the potential benefit justifies the risk to the fetus. Careful monitoring is advised.

Breast-feeding

Corticosteroids are excreted in breast milk; caution is advised. Monitor the infant for potential effects.

Storage

Store in a cool, dry place, away from light. Keep out of reach of children.

Formulations

• Tablets
• Injectable solutions
• Topical preparations

Indications

• Methemoglobinemia
• Urinary tract infections
• Laboratory staining agent

Dosage

Children: Refer to the BNF for Children for specific dosing recommendations based on the condition being treated.

Adults: Refer to the BNF for specific dosing recommendations based on the condition being treated.

Mechanism of action

Methylene blue acts as a reducing agent that facilitates the conversion of methemoglobin back to hemoglobin. It does this by donating electrons to the ferric ion in methemoglobin, reducing it to ferrous iron, which restores the molecule's ability to transport oxygen. It also has mild monoamine oxidase inhibitor activity, affecting neurotransmitter metabolism.

Pharmacodynamics

Methylene blue exhibits a variety of pharmacodynamic effects, primarily through its action on hemoglobin. By reducing methemoglobin levels, it improves oxygen delivery to tissues. Additionally, it has been noted to possess properties such as antimicrobial activity and potential neuroprotective effects in certain contexts. The overall effect is a restoration of normal oxygen transport and metabolism.

Pharmacokinetics

Methylene blue is rapidly absorbed after intravenous administration, with peak plasma concentrations occurring shortly after dosing. It is distributed widely in body tissues, including the liver and kidneys. The drug undergoes hepatic metabolism, primarily by the cytochrome P450 system, and is excreted mainly in the urine as metabolites. The elimination half-life is approximately 5 to 6 hours, but this can vary depending on dosage and patient factors.

Pregnancy

Safety in pregnancy has not been established.

Breast-feeding

There is no information available regarding its excretion in human milk.

Storage

Store in a well-closed container in a cool, dry place.

Mechanism of action

Methylsulphate functions as a methylating agent, transferring a methyl group to nucleophiles. This process involves the formation of a sulfonium ion, which is highly reactive and can readily react with nucleophilic sites on various substrates, leading to methylation reactions.

Pharmacodynamics

The pharmacodynamics of methylsulphate is primarily related to its role as a methylating agent in biochemical reactions. It can alter the structure and function of biological molecules, potentially affecting cellular processes and signaling pathways. However, detailed pharmacodynamic studies specific to therapeutic use are limited.

Pharmacokinetics

There is limited information on the pharmacokinetics of methylsulphate, given its typical use as a reagent in laboratory settings rather than a clinical drug. When used in chemical reactions, its reactivity and transformation into other compounds would dictate its pharmacokinetic profile, which could vary significantly based on the specific context of use.

Pregnancy

There is limited data on the use of methylsulphate in pregnancy. Consult relevant guidelines.

Breast-feeding

Data on the excretion of methylsulphate in human milk is not available. Caution is advised.

Storage

Store in a cool, dry place, away from direct sunlight.

Indications

• Tablet coating
• Granule coating
• Improvement of drug stability
• Taste masking
• Aesthetic enhancement of pharmaceuticals

Dosage

Children: Dosage will depend on the specific formulation and active ingredients of the medication being coated. Refer to the specific product information for guidance.

Adults: Dosage will depend on the specific formulation and active ingredients of the medication being coated. Refer to the specific product information for guidance.

Mechanism of action

Opadry functions primarily as a coating polymer that adheres to the surface of tablets or granules, creating a protective layer. This layer can control the release of the active ingredient and protect it from environmental factors such as moisture and light. The specific composition of Opadry can vary, but it typically includes film-forming agents, plasticizers, and colorants that work together to achieve the desired coating characteristics.

Pharmacodynamics

The pharmacodynamics of Opadry is largely focused on its physical and chemical properties rather than specific biological interactions. The coating alters the dissolution characteristics of the drug, potentially leading to modified release profiles. This can enhance drug bioavailability or control the release rate of the active ingredient, thereby impacting the therapeutic effect.

Pharmacokinetics

As a coating agent, Opadry itself is not absorbed into the systemic circulation and does not have pharmacokinetic properties related to absorption, distribution, metabolism, or excretion of an active pharmaceutical ingredient. Its impact on pharmacokinetics is indirect, as it affects how the active drug is released and absorbed in the gastrointestinal tract.

Pregnancy

Opadry is a film-coating agent, and specific studies on its effects during pregnancy are not well-documented. Generally, it is advisable to use medications cautiously during pregnancy. Consult a healthcare provider for guidance.

Breast-feeding

Limited data are available regarding the safety of Opadry during breastfeeding. It is recommended to consult a healthcare provider before use.

Storage

Store in a cool, dry place away from direct sunlight and moisture. Keep out of reach of children.

Formulations

• Opadry OY - a coating system for oral solid dosage forms
• Opadry II - a polymer-based coating system for tablet and capsule applications

Indications

• Constipation
• Bowel preparation prior to surgical procedures or diagnostic tests

Dosage

Children: Refer to specific guidelines or BNF for Children for dosing information.

Adults: Refer to specific guidelines or BNF for detailed dosing information.

Mechanism of action

Polyethylene glycol works by osmotically retaining water in the intestinal lumen, which increases the water content of the stool. This enhances the passage of stool through the intestines and promotes bowel movements. The high molecular weight of polyethylene glycol prevents its absorption in the gastrointestinal tract, ensuring that it remains in the lumen to exert its effects.

Pharmacodynamics

The pharmacodynamic profile of polyethylene glycol involves its ability to increase stool water content, thereby reducing stool consistency and facilitating easier passage. It does not stimulate intestinal motility directly but rather relies on the osmotic effect to promote bowel evacuation. The onset of action typically occurs within 24 to 96 hours after ingestion.

Pharmacokinetics

Polyethylene glycol is not absorbed systemically, and its pharmacokinetics are characterized by its presence solely in the gastrointestinal tract. It is excreted unchanged in the stool. The volume of polyethylene glycol administered can influence the effectiveness and timing of its action, but its absorption is negligible, making systemic side effects rare.

Adverse effects

• Abdominal cramping
• Diarrhea
• Nausea
• Vomiting
• Bloating
• Flatulence

Precautions

• Use with caution in patients with gastrointestinal disorders or bowel obstruction.
• Ensure adequate hydration during use to prevent dehydration.

Pregnancy

Polyethylene glycol is generally considered safe during pregnancy, but should be used under medical supervision.

Breast-feeding

Polyethylene glycol is excreted in breast milk in very small amounts and is generally regarded as safe during breastfeeding.

Storage

Store at room temperature, away from moisture and heat.

Formulations

• Powder for oral solution
• Liquid formulation

Indications

• Topical antiseptic for skin disinfection
• Surgical scrubs and hand sanitizers
• Wound care management
• Pharmaceutical excipient in solid and liquid formulations

Dosage

Children: Refer to specific product guidelines for pediatric dosing recommendations, as doses can vary based on formulation and intended use.

Adults: Refer to specific product guidelines for dosing recommendations, as doses can vary based on the formulation and intended use.

Mechanism of action

Povidone acts by forming a complex with iodine when used as an antiseptic, which releases iodine slowly to exert its antimicrobial effect. The iodine disrupts microbial cell walls and interferes with protein synthesis, leading to cell death. Additionally, as a polymer, povidone can enhance drug solubility and stability by forming a hydrophilic matrix.

Pharmacodynamics

Povidone has a broad spectrum of antimicrobial activity against bacteria, viruses, and fungi. Its antiseptic properties are primarily due to the release of iodine, which is effective in reducing microbial load and preventing infection. The polymer's ability to bind to various substances allows it to be utilized in formulations that require improved stability and solubility.

Pharmacokinetics

Povidone is not absorbed systemically when applied topically, as it remains localized at the site of application. Its pharmacokinetics are largely dependent on the formulation and route of administration, with the polymer being metabolized by hydrolysis and excreted in urine as low-molecular-weight compounds. The release and activity of iodine are influenced by the concentration of povidone and the presence of organic matter.

Adverse effects

• Local irritation
• Allergic reactions
• Skin rashes
• Hypersensitivity reactions

Precautions

• Use with caution in patients with known allergies to iodine or povidone-iodine
• Avoid use in deep puncture wounds or serious burns

Pregnancy

Povidone is generally considered safe for use during pregnancy, but it is advisable to consult a healthcare professional before use.

Breast-feeding

Povidone is considered safe during breastfeeding, but it is recommended to consult a healthcare professional.

Storage

Store at room temperature, away from moisture and heat. Keep the container tightly closed.

Formulations

• Topical solution
• Ointment
• Surgical scrub
• Gauze impregnated with povidone-iodine

Indications

• Hyperthyroidism
• Graves' disease
• Thyroid storm

Dosage

Children: Refer to the BNF

Adults: The usual initial dose of propylthiouracil in adults is 300 mg per day, divided into 3 doses. The maintenance dose is typically 100-150 mg per day, adjusted based on thyroid function tests.

Mechanism of action

Propylthiouracil acts by inhibiting the enzyme thyroid peroxidase, which is involved in the iodination of tyrosine residues in thyroglobulin, a precursor of thyroid hormones. By blocking this enzyme, PTU reduces the production of thyroxine (T4) and triiodothyronine (T3), leading to decreased thyroid hormone levels in circulation. Additionally, PTU inhibits the conversion of T4 to T3 in peripheral tissues, further contributing to its antithyroid effects.

Pharmacodynamics

The pharmacodynamic effects of propylthiouracil are primarily centered around its ability to lower thyroid hormone levels, which helps alleviate symptoms of hyperthyroidism such as increased heart rate, weight loss, and anxiety. The onset of action can vary, but therapeutic effects may be observed within several weeks of initiation. Monitoring thyroid function tests is essential to assess the efficacy and adjust dosing as needed.

Pharmacokinetics

Propylthiouracil is well absorbed from the gastrointestinal tract, though its bioavailability can be affected by factors such as food intake. The drug is extensively metabolized in the liver, and its elimination half-life averages around 1-2 hours. Most of the drug is excreted in urine as metabolites. It is important to note that due to its rapid metabolism, multiple daily doses may be required to maintain therapeutic levels.

Interactions

• propylthiouracil+metyrapone: Severe (decreases effects)

Dosage

Children: Refer to specific drug formulations and product labels as purified substances can vary widely in their use and dosing.

Adults: Refer to specific drug formulations and product labels as purified substances can vary widely in their use and dosing.

Mechanism of action

The mechanism of action for purified compounds varies widely depending on the specific substance. Generally, purified drugs exert their effects by interacting with specific biological targets, such as receptors, enzymes, or ion channels, leading to a desired therapeutic effect. This interaction can involve binding to receptors to activate or inhibit signaling pathways, modulating enzymatic activity, or altering physiological processes.

Pharmacodynamics

Pharmacodynamics describes the effects of a drug on the body and the relationship between drug concentration and effect. For purified drugs, this can involve dose-response relationships and the time course of their action. The purified form often enhances potency and reduces variability in response among patients, which can lead to more predictable therapeutic outcomes. The overall effect is determined by the drug's affinity for its target, the efficacy of the drug-receptor interaction, and the downstream signaling pathways activated as a result of this interaction.

Pharmacokinetics

Pharmacokinetics involves the absorption, distribution, metabolism, and excretion (ADME) of a drug. For purified substances, absorption can be more efficient due to the absence of impurities that may affect solubility or stability. Distribution may also be enhanced, leading to higher bioavailability. Metabolism can be influenced by the structure of the purified compound, as it may be metabolized more readily by liver enzymes. Excretion typically occurs through the kidneys or liver, depending on the molecular characteristics of the purified drug.

Pregnancy

Consult with a healthcare professional, as the safety of purified forms of medications during pregnancy may vary depending on the specific substance.

Breast-feeding

Consult with a healthcare professional, as the safety of purified forms of medications during breastfeeding may vary depending on the specific substance.

Storage

Store in a cool, dry place, away from light and moisture, and keep out of reach of children.

Indications

• Wound management
• Silicone implants
• Dermal fillers
• Medical lubricants
• Scar treatment

Dosage

Children: Refer to specific product guidelines for paediatric dosages, as silicone applications vary widely.

Adults: Refer to specific product guidelines for adult dosages, as silicone applications vary widely.

Mechanism of action

Silicones exhibit their effects primarily through their physical properties rather than a specific biochemical mechanism. They form a protective barrier that is hydrophobic, preventing moisture and microbial penetration, which aids in wound healing and reduces the risk of infection. Their flexibility and inertness also allow them to integrate well with biological tissues.

Pharmacodynamics

Silicones are generally inert and do not interact significantly with biological systems. They provide mechanical support, lubricate surfaces, and facilitate healing without eliciting a strong immune response. Their low toxicity and biocompatibility contribute to their favorable pharmacodynamic profile in medical applications.

Pharmacokinetics

Silicones are not absorbed by the body when used in medical applications. They remain at the site of application and do not undergo significant metabolism. Their elimination is largely through physical means, including degradation over time or removal during surgical procedures. The pharmacokinetic properties can vary depending on the specific silicone formulation and application.

Pregnancy

Silicone is generally considered safe for use during pregnancy as it is inert and non-toxic. However, specific products should be evaluated for safety.

Breast-feeding

Silicone is also considered safe during breastfeeding as it does not transfer into milk; however, care should be taken with specific formulations.

Storage

Store in a cool, dry place away from direct sunlight.

Indications

• Type 2 diabetes mellitus as monotherapy (if metformin is inappropriate)
• Type 2 diabetes mellitus in combination with other antidiabetic drugs (including insulin) when metformin alone or in combination fails to achieve adequate glycemic control

Dosage

Adults: 100 mg once daily, or 50 mg twice daily when used in combination with a sulfonylurea or insulin. Dose adjustments may be required based on renal function.

Mechanism of action

Sitagliptin inhibits the enzyme dipeptidyl peptidase-4 (DPP-4), which is responsible for the degradation of incretin hormones. This inhibition results in prolonged active incretin levels, which enhances insulin secretion from pancreatic beta cells and decreases glucagon secretion from alpha cells in the pancreas, leading to lowered blood glucose levels.

Pharmacodynamics

Sitagliptin's pharmacodynamic effects include improved glycemic control, characterized by reduced fasting and postprandial blood glucose levels. The drug is effective in lowering HbA1c levels and is associated with a low risk of hypoglycemia. It has a beneficial effect on weight management, as it typically does not promote weight gain.

Pharmacokinetics

Sitagliptin is absorbed rapidly after oral administration, with peak plasma concentrations occurring within 1-4 hours. Its bioavailability is approximately 87%. The drug is predominantly eliminated via renal excretion, with about 80% of the dose excreted unchanged in the urine. The elimination half-life is approximately 12.4 hours. Renal impairment may necessitate dose adjustments, as clearance is significantly reduced in patients with decreased renal function.

Contra-indications

• History of pancreatitis
• Severe heart failure

Adverse effects

• Headache
• Constipation
• Dizziness
• Skin reactions
• Angioedema
• Back pain
• Cutaneous vasculitis
• Joint disorders
• Myalgia
• Acute pancreatitis
• Acute renal impairment
• Stevens-Johnson syndrome
• Vomiting

Interactions

• Concomitant use with sulfonylureas or insulin may require dose adjustments
• Moderate interaction with vemurafenib (increases exposure)

Precautions

• Monitor renal function before treatment and periodically thereafter
• Discontinue if symptoms of acute pancreatitis occur, such as persistent severe abdominal pain

Pregnancy

Avoid-toxicity observed in animal studies.

Breast-feeding

Avoid-present in milk in animal studies.

Storage

Store at room temperature, away from moisture and heat.

Formulations

• Tablets: 50 mg, 100 mg

Indications

• Dry skin conditions
• Cosmetic formulations
• Emollient in topical creams and lotions
• Emulsifying agent in pharmaceutical preparations

Dosage

Children: For pediatric use, refer to specific product formulations and guidelines, as dosing may vary based on the formulation and concentration.

Adults: Stearyl alcohol is used topically in various formulations. Specific dosing is typically determined by the formulation and intended use, refer to product guidelines for detailed instructions.

Mechanism of action

Stearyl alcohol functions primarily as an emollient and emulsifier. It aids in the formation of stable emulsions by reducing the surface tension between oil and water phases, allowing for the creation of creams and lotions. Its hydrophobic tail interacts with lipids, while the hydroxyl group can form hydrogen bonds with water, enhancing moisture retention in the skin.

Pharmacodynamics

Stearyl alcohol acts by providing a protective barrier on the skin, reducing transepidermal water loss and enhancing hydration. Its emollient properties make it effective in softening and smoothing the skin, which can alleviate dryness and improve the overall appearance of the skin. Additionally, it can enhance the delivery of other active ingredients in topical formulations.

Pharmacokinetics

Stearyl alcohol is not significantly absorbed systemically when applied topically. Its primary action is local to the site of application, where it exerts its emollient effects. The compound is metabolized in the body to various fatty acids and alcohols, and it is excreted primarily through the skin and gastrointestinal tract, with minimal systemic exposure.

Pregnancy

Stearyl is generally considered safe for use during pregnancy; however, specific formulations should be evaluated for their ingredients.

Breast-feeding

Stearyl can be used while breastfeeding, but it's recommended to consult a healthcare provider for specific concerns regarding topical applications.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Cream
• Ointment
• Lotion

Mechanism of action

Ethanol affects the brain’s neurons in several ways. It alters their membranes as well as their ion channels, enzymes, and receptors. Alcohol also binds directly to the receptors for acetylcholine, serotonin, GABA, and the NMDA receptors for glutamate. The sedative effects of ethanol are mediated through binding to GABA receptors and glycine receptors (alpha 1 and alpha 2 subunits). It also inhibits NMDA receptor functioning. In its role as an anti-infective, ethanol acts as an osmolyte or dehydrating agent that disrupts the osmotic balance across cell membranes. ... Ethanol is known to affect a large number of membrane proteins that participate in signaling pathways such as neurotransmitter receptors, enzymes, and ion channels, and there is extensive evidence that ethanol interacts with a variety of neurotransmitters. The major actions of ethanol involve enhancing the inhibitory effects of gamma-aminobutyric acid (GABA) at GABAa receptors and blockade of the N-methyl-D-aspartate (NMDA) subtype of glutamate, an excitatory amine acid (EAA) receptor. Animal studies indicate that the acute effects of ethanol result from competitive inhibition of glycine binding to NMDA receptor and disruption of glutamatergic neurotransmission by inhibiting the response of the NMDA receptor. Persistent glycine antagonism and attenuation of glutamatergic neurotransmission by chronic ethanol exposure results in tolerance to ethanol by enhancing EAA neurotransmission and NMDA receptor upregulation. The latter appears to involve selective increases in NMDA R2B subunit concentrations and other molecular changes in specific brain loci. The abrupt withdrawal of ethanol thus produces a hyperexcitable state that leads to the ethanol withdrawal syndrome and excitotoxic neuronal death. GABA-mediated inhibition, which normally acts to limit excitation, is eliminated during ethanol withdrawal syndrome and further intensifies this excitation. In addition, NMDA receptors function to inhibit the release of dopamine in the nucleus accumbens and mesolimbic structures, which modulate the reinforcing action of addictive xenobiotics such as ethanol. By inhibiting NMDA receptor activity, ethanol could increase dopamine release from the nucleus accumbens and ventral tegmental area and could thus create dependence. Chronic ethanol administration also results in tolerance, dependence, and an ethanol withdrawal syndrome, mediated, in part, by desensitization and or downregulation of GABAa receptors. The development of alcoholic ketoacidosis (AKA) requires that a combination of physical and physiologic events occur. The normal response to starvation and depletion of hepatic glycogen stores is for amino acids to be converted to pyruvate. Pyruvate can serve as a substrate for gluconeogenesis, be converted to acetyl-CoA, which can enter the Krebs cycle or can be utilized in various biosynthetic pathways (eg, fatty acid, ketone bodies, cholesterol, and acetylcholine) ... Ethanol metabolism generates NADH, resulting in an excess of reducing potential. This high redox state favors the conversion of pyruvate to lactate, diverting pyruvate from being a substrate for gluconeogenesis. To compensate for the lack of normal metabolic substrates, the body mobilizes fat from adipose tissue and increased fatty acid metabolism as an alternative source of energy. This response is mediated by a decrease in insulin and an increased secretion of glucagon, catecholamines, growth hormone, and cortisol. Fatty acid metabolism results in the formation of acetyl-CoA and it combines with the excess acetate that is generated from ethanol metabolism to form acetoacetate. Most of the acetoacetate is reduced to beta-hydroxybutyrate due to the excess reducing potential or high redox state of the cell. Volume depletion interferes with the renal elimination of acetoacetate and beta-hydroxybutyrate, and contributes to the acidosis. An elevated lactate concentration may result from shunting from pyruvate or

Pharmacodynamics

Alcohol produces injury to cells by dehydration and precipitation of the cytoplasm or protoplasm. This accounts for its bacteriocidal and antifungal action. When alcohol is injected in close proximity to nerve tissues, it produces neuritis and nerve degeneration (neurolysis). Ninety to 98% of ethanol that enters the body is completely oxidized. Ethanol is also used as a cosolvent to dissolve many insoluble drugs and to serve as a mild sedative in some medicinal formulations. Ethanol also binds to GABA, glycine, NMDA receptors and modulates their effects. Ethanol is also metabolised by the hepatic enzyme alcohol dehydrogenase.

Mechanism of action

Metformin is widely used to treat hyperglycemia. However, metformin treatment may induce intrahepatic cholestasis and liver injury in a few patients with type II diabetes through an unknown mechanism. Here we show that metformin decreases SIRT1 protein levels in primary hepatocytes and liver. Both metformin-treated wild-type C57 mice and hepatic SIRT1-mutant mice had increased hepatic and serum bile acid levels. However, metformin failed to change systemic bile acid levels in hepatic SIRT1-mutant mice. Molecular mechanism study indicates that SIRT1 directly interacts with and deacetylates Foxa2 to inhibit its transcriptional activity on expression of genes involved in bile acids synthesis and transport. Hepatic SIRT1 mutation elevates Foxa2 acetylation levels, which promotes Foxa2 binding to and activating genes involved in bile acids metabolism, impairing hepatic and systemic bile acid homeostasis. Our data clearly suggest that hepatic SIRT1 mediates metformin effects on systemic bile acid metabolism and modulation of SIRT1 activity in liver may be an attractive approach for treatment of bile acid-related diseases such as cholestasis. Metformin is antihyperglycemic, not hypoglycemic. It does not cause insulin release from the pancreas and does not cause hypoglycemia, even in large doses. Metformin has no significant effects on the secretion of glucagon, cortisol, growth hormone or somatostatin. Metformin reduces glucose levels primarily by decreasing hepatic glucose production and by increasing insulin action in muscle and fat. ... May decrease plasma glucose by reducing the absorption of glucose from the intestine. /Salt not specified/ Metformin potentiates the effect of insulin by mechanisms not fully understood. Metformin does not stimulate pancreatic beta cells to increase secretion of insulin; insulin secretion must be present for metformin to work properly. It is postulated that metformin decreases hepatic glucose production and improves insulin sensitivity by increasing peripheral glucose uptake and utilization. /Salt not specified/ People with Type 2 diabetes mellitus (T2DM) have reduced bone mineral density and an increased risk of fractures due to altered mesenchymal stem cell (MSC) differentiation in the bone marrow. This leads to a shift in the balance of differentiation away from bone formation (osteogenesis) in favour of fat cell development (adipogenesis). The commonly used anti-diabetic drug, metformin, activates the osteogenic transcription factor Runt-related transcription factor 2 (Runx2), which may suppress adipogenesis, leading to improved bone health. Here we investigate the involvement of the metabolic enzyme, AMP-activated protein kinase (AMPK), in these protective actions of metformin. The anti-adipogenic actions of metformin were observed in multipotent C3H10T1/2 MSCs, in which metformin exerted reciprocal control over the activities of Runx2 and the adipogenic transcription factor, PPARgamma, leading to suppression of adipogenesis. These effects appeared to be independent of AMPK activation but rather through the suppression of the mTOR/p70S6K signalling pathway. Basal AMPK and mTOR/p70S6K activity did appear to be required for adipogenesis, as demonstrated by the use of the AMPK inhibitor, compound C. This observation was further supported by using AMPK knockout mouse embryo fibroblasts (MEFs) where adipogenesis, as assessed by reduced lipid accumulation and expression of the adipogeneic transcription factor, C/EBPbeta, was found to display an absolute requirement for AMPK. Further activation of AMPK in wild type MEFS, with either metformin or the AMPK-specific activator, A769662, was also associated with suppression of adipogenesis. It appears, therefore, that basal AMPK activity is required for adipogenesis and that metformin can inhibit adipogenesis through AMPK-dependent or -independent mechanisms, depending on the cellular context.

Mechanism of action

Ethylene glycol is metabolized by alcohol dehydrogenase to glycoaldehyde, which is then metabolized to glycolic, glyoxylic, and oxalic acids. These acids, along with excess lactic acid are responsible for the anion gap metabolic acidosis. Oxalic acid readily precipitates with calcium to form insoluble calcium oxalate crystals. Tissue injury is caused by widespread deposition of oxalate crystals and the toxic effects of glycolic and glyoxylic acids.

Mechanism of action

Metformin's mechanisms of action are unique from other classes of oral antihyperglycemic drugs. Metformin decreases blood glucose levels by decreasing hepatic glucose production (also called gluconeogenesis), decreasing the intestinal absorption of glucose, and increasing insulin sensitivity by increasing peripheral glucose uptake and utilization. It is well established that metformin inhibits mitochondrial complex I activity, and it has since been generally postulated that its potent antidiabetic effects occur through this mechanism. The above processes lead to a decrease in blood glucose, managing type II diabetes and exerting positive effects on glycemic control. After ingestion, the organic cation transporter-1 (OCT1) is responsible for the uptake of metformin into hepatocytes (liver cells). As this drug is positively charged, it accumulates in cells and in the mitochondria because of the membrane potentials across the plasma membrane as well as the mitochondrial inner membrane. Metformin inhibits mitochondrial complex I, preventing the production of mitochondrial ATP leading to increased cytoplasmic ADP:ATP and AMP:ATP ratios. These changes activate AMP-activated protein kinase (AMPK), an enzyme that plays an important role in the regulation of glucose metabolism. Aside from this mechanism, AMPK can be activated by a lysosomal mechanism involving other activators. Following this process, increases in AMP:ATP ratio also inhibit _fructose-1,6-bisphosphatase_ enzyme, resulting in the inhibition of gluconeogenesis, while also inhibiting _adenylate cyclase_ and decreasing the production of cyclic adenosine monophosphate (cAMP), a derivative of ATP used for cell signaling. Activated AMPK phosphorylates two isoforms of acetyl-CoA carboxylase enzyme, thereby inhibiting fat synthesis and leading to fat oxidation, reducing hepatic lipid stores and increasing liver sensitivity to insulin. In the intestines, metformin increases anaerobic glucose metabolism in enterocytes (intestinal cells), leading to reduced net glucose uptake and increased delivery of lactate to the liver. Recent studies have also implicated the gut as a primary site of action of metformin and suggest that the liver may not be as important for metformin action in patients with type 2 diabetes. Some of the ways metformin may play a role on the intestines is by promoting the metabolism of glucose by increasing glucagon-like peptide I (GLP-1) as well as increasing gut utilization of glucose. In addition to the above pathway, the mechanism of action of metformin may be explained by other ways, and its exact mechanism of action has been under extensive study in recent years. Metformin is widely used to treat hyperglycemia. However, metformin treatment may induce intrahepatic cholestasis and liver injury in a few patients with type II diabetes through an unknown mechanism. Here we show that metformin decreases SIRT1 protein levels in primary hepatocytes and liver. Both metformin-treated wild-type C57 mice and hepatic SIRT1-mutant mice had increased hepatic and serum bile acid levels. However, metformin failed to change systemic bile acid levels in hepatic SIRT1-mutant mice. Molecular mechanism study indicates that SIRT1 directly interacts with and deacetylates Foxa2 to inhibit its transcriptional activity on expression of genes involved in bile acids synthesis and transport. Hepatic SIRT1 mutation elevates Foxa2 acetylation levels, which promotes Foxa2 binding to and activating genes involved in bile acids metabolism, impairing hepatic and systemic bile acid homeostasis. Our data clearly suggest that hepatic SIRT1 mediates metformin effects on systemic bile acid metabolism and modulation of SIRT1 activity in liver may be an attractive approach for treatment of bile acid-related diseases such as cholestasis. Metformin is antihyperglycemic, not hypoglycemic. It does not cause insulin release from the pancreas and does not cause hypoglycemia, even in large doses. Me

Pharmacodynamics

**General effects** Insulin is an important hormone that regulates blood glucose levels. Type II diabetes is characterized by a decrease in sensitivity to insulin, resulting in elevations in blood glucose when the pancreas can no longer compensate. In patients diagnosed with type 2 diabetes, insulin is unable to exert adequate effects on tissues and cells (i.e. insulin resistance) and insulin deficiency may also be present. Metformin reduces hepatic production of glucose, decreases the intestinal absorption of glucose, and enhances insulin sensitivity by increasing both peripheral glucose uptake and utilization. In contrast with drugs of the sulfonylurea class, which lead to hyperinsulinemia, the secretion of insulin is unchanged with metformin use. **Effect on fasting plasma glucose (FPG) and Glycosylated hemoglobin (HbA1c)** HbA1c is an important periodic measure of glycemic control used to monitor diabetic patients. Fasting plasma glucose is also a useful and important measure of glycemic control. In a 29-week clinical trial of subjects diagnosed with type II diabetes, metformin decreased the fasting plasma glucose levels by an average of 59 mg/dL from baseline, compared to an average increase of 6.3 mg/dL from baseline in subjects taking a placebo. Glycosylated hemoglobin (HbA1c) was decreased by about 1.4% in subjects receiving metformin, and increased by 0.4% in subjects receiving placebo only.

Mechanism of action

Inhibition of DPP-4 by sitagliptin slows DPP-4 mediated inactivation of incretins like GLP-1 and GIP. Incretins are released throughout the day and upregulated in response to meals as part of glucose homeostasis. Reduced inhibition of incretins increase insulin synthesis and decrease glucagon release in a manner dependant on glucose concentrations. These effects lead to an overall increase in blood glucose control which is demonstrated by reduced glycosylated hemoglobin (HbA1c). Januvia is a member of a class of oral anti-hyperglycemic agents called dipeptidyl peptidase 4 (DPP-4) inhibitors. The improvement in glycemic control observed with this medicinal product may be mediated by enhancing the levels of active incretin hormones. Incretin hormones, including glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), are released by the intestine throughout the day, and levels are increased in response to a meal. The incretins are part of an endogenous system involved in the physiologic regulation of glucose homeostasis. When blood glucose concentrations are normal or elevated, GLP-1 and GIP increase insulin synthesis and release from pancreatic beta cells by intracellular signaling pathways involving cyclic AMP. Treatment with GLP-1 or with DPP-4 inhibitors in animal models of type 2 diabetes has been demonstrated to improve beta cell responsiveness to glucose and stimulate insulin biosynthesis and release. With higher insulin levels, tissue glucose uptake is enhanced. In addition, GLP-1 lowers glucagon secretion from pancreatic alpha cells. Decreased glucagon concentrations, along with higher insulin levels, lead to reduced hepatic glucose production, resulting in a decrease in blood glucose levels. The effects of GLP-1 and GIP are glucose-dependent such that when blood glucose concentrations are low, stimulation of insulin release and suppression of glucagon secretion by GLP-1 are not observed. For both GLP-1 and GIP, stimulation of insulin release is enhanced as glucose rises above normal concentrations. Further, GLP-1 does not impair the normal glucagon response to hypoglycemia. The activity of GLP-1 and GIP is limited by the DPP-4 enzyme, which rapidly hydrolyzes the incretin hormones to produce inactive products. Sitagliptin prevents the hydrolysis of incretin hormones by DPP-4, thereby increasing plasma concentrations of the active forms of GLP-1 and GIP. By enhancing active incretin levels, sitagliptin increases insulin release and decreases glucagon levels in a glucose-dependent manner. In patients with type 2 diabetes with hyperglycemia, these changes in insulin and glucagon levels lead to lower hemoglobin A1c (HbA1c) and lower fasting and postprandial glucose concentrations. The glucose-dependent mechanism of sitagliptin is distinct from the mechanism of sulfonylureas, which increase insulin secretion even when glucose levels are low and can lead to hypoglycemia in patients with type 2 diabetes and in normal subjects. Sitagliptin is a potent and highly selective inhibitor of the enzyme DPP-4 and does not inhibit the closely-related enzymes DPP-8 or DPP-9 at therapeutic concentrations. Sitagliptin is a DPP-4 inhibitor, which is believed to exert its actions in patients with type 2 diabetes by slowing the inactivation of incretin hormones. Concentrations of the active intact hormones are increased by Januvia, thereby increasing and prolonging the action of these hormones. Incretin hormones, including glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), are released by the intestine throughout the day, and levels are increased in response to a meal. These hormones are rapidly inactivated by the enzyme, DPP-4. The incretins are part of an endogenous system involved in the physiologic regulation of glucose homeostasis. When blood glucose concentrations are normal or elevated, GLP-1 and GIP increase insulin synthesis and release from pancreatic beta cells by

Pharmacodynamics

Sitagliptin inhibits DPP-4 which leads to increased levels of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide(GIP), decreased levels of glucagon, and a stronger insulin response to glucose.