Yasmin Plus

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

• Hormonal contraception
• Menstrual cycle regulation
• Hormone replacement therapy
• Management of menopausal symptoms
• Treatment of polycystic ovary syndrome
• Endometriosis management
• Dysfunctional uterine bleeding

Dosage

Adults: The dosing of ethinylestradiol varies based on the formulation and indication. Commonly, it is administered in combination with progestins for contraception, typically as a daily oral tablet containing 20 to 35 micrograms of ethinyles

Mechanism of action

Ethinylestradiol acts as a synthetic estrogen by binding to estrogen receptors in estrogen-responsive tissues. It suppresses gonadotropic hormone secretion from the pituitary gland, leading to decreased luteinizing hormone levels. This results in reduced endometrial vascularization and prevents ovulation by inhibiting the hormonal changes necessary for ovarian follicle maturation. Additionally, it thickens cervical mucus to impede sperm movement and alters the endometrium to prevent implantation.

Pharmacodynamics

Ethinylestradiol has a long duration of action and a wide therapeutic index. It effectively decreases luteinizing hormone and gonadotropic hormone levels, thereby preventing ovulation and altering reproductive tract conditions. Patients using ethinylestradiol should be made aware of potential thrombotic risks, particularly in specific populations such as smokers and those with a history of thromboembolic disorders.

Pharmacokinetics

Ethinylestradiol is well absorbed when taken orally, with peak plasma concentrations occurring approximately 1 to 2 hours after administration. It has a high plasma protein binding rate, predominantly to sex hormone-binding globulin. The drug undergoes extensive hepatic metabolism, primarily by cytochrome P450 enzymes, and has a half-life of about 10-20 hours. Excretion is primarily via the kidneys, with metabolites being eliminated in urine.

Contra-indications

• Pregnancy
• History of thromboembolic disorders
• Active liver disease
• Severe hypertension
• Undiagnosed vaginal bleeding
• Hormone-sensitive cancers (e.g., breast cancer)
• Known hypersensitivity to ethinylestradiol or any component of the formulation

Adverse effects

• Nausea
• Headache
• Breast tenderness
• Mood changes
• Thromboembolic events (e.g., deep vein thrombosis, pulmonary embolism)
• Increased risk of certain cancers (e.g., breast and endometrial cancer)
• Hypertension
• Skin reactions (e.g., rash)

Interactions

• Antibiotics (e.g., rifampicin) may reduce effectiveness
• Anticonvulsants (e.g., phenytoin, carbamazepine) may reduce effectiveness
• St. John's Wort may reduce effectiveness
• Fostemsavir increases ethinylestradiol concentration
• Certain antiretrovirals may interact with ethinylestradiol

Precautions

• Monitor for signs of thromboembolism
• Caution in patients with a history of migraines
• Caution in patients with liver disease
• Regular breast examinations and mammograms are recommended
• Consider risks versus benefits in patients with a family history of breast cancer
• Use with caution in patients with hypertension, renal disease, asthma, epilepsy, and systemic lupus erythematosus

Pregnancy

Ethinylestradiol is contraindicated in pregnancy due to potential risks to the fetus and maternal health.

Breast-feeding

Caution is advised as ethinylestradiol may be excreted in breast milk. It is recommended to weigh the benefits of the treatment against potential risks to the nursing infant.

Storage

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

Formulations

• Tablets
• Transdermal patches
• Gels
• Sachets

Indications

• Solubilization of poorly soluble drugs
• Improving the bioavailability of hydrophobic medications
• Pharmaceutical formulations requiring enhanced drug stability

Dosage

Children: Refer to the BNF for Children for dosage recommendations, as pediatric dosing must be determined based on age, weight, and the specific indication.

Adults: Refer to the specific product information or BNF for dosing guidance, as dosages can vary based on the formulation and the drug being solubilized.

Mechanism of action

Betadex functions primarily by forming inclusion complexes with hydrophobic drugs. The lipophilic drug molecules are encapsulated within the hydrophobic cavity of the betadex molecule, resulting in increased solubility and stability of the drug in solution. This mechanism enhances drug bioavailability, allowing for better therapeutic effects and reduced side effects associated with solubility issues.

Pharmacodynamics

The pharmacodynamics of betadex is largely related to its ability to solubilize and stabilize various drug compounds. By enhancing solubility, it increases the drug's absorption in systemic circulation, thus improving its pharmacological action. The formation of inclusion complexes can also modify the drug's release profile, potentially leading to altered pharmacokinetics and efficacy.

Pharmacokinetics

Betadex is not significantly absorbed through the gastrointestinal tract when administered orally. Its pharmacokinetics are influenced by its formulation and the nature of the drug it complexes with. Following injection, complexed drugs may exhibit altered distribution and elimination profiles, depending on the characteristics of both betadex and the drug. The excretion of betadex occurs primarily via the kidneys, with minimal metabolism.

Pregnancy

There is limited data on the use of betadex during pregnancy. Caution is advised.

Breast-feeding

Data on the excretion of betadex in human breast milk is not available. Caution is recommended.

Storage

Store at room temperature, away from light and moisture.

Formulations

• {'name': 'Betadex', 'type': 'Powder for solution'}

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

Dosage

Children: Refer to established pharmacological guidelines for specific dosing related to clathrates in paediatrics, as this can vary widely based on the application and formulation.

Adults: Refer to established pharmacological guidelines for specific dosing related to clathrates, as this can vary widely based on the application and formulation.

Mechanism of action

Clathrates function by encapsulating guest molecules within a lattice of host molecules, often involving water or hydrocarbons. The host structure creates a stable environment that can enhance the stability and bioavailability of the encapsulated substance. This mechanism can influence the release kinetics of the guest molecule when administered in a biological system.

Pharmacodynamics

The pharmacodynamics of clathrates largely depend on their ability to encapsulate and release guest molecules in a controlled manner. This can lead to increased solubility of poorly water-soluble drugs, prolonged activity of certain medications, and targeted delivery to specific tissues or cells. The effects observed are contingent on the nature of both the host and guest molecules.

Pharmacokinetics

The pharmacokinetics of clathrate compounds can vary based on the specific type of clathrate and the guest molecules encapsulated. Generally, factors such as absorption, distribution, metabolism, and excretion (ADME) will be influenced by the interactions between the host and guest. For instance, clathrates may enhance the absorption of certain drugs through improved solubility and stability, while the metabolism and excretion may depend on the guest molecules' properties.

Pregnancy

There is limited data on the use of clathrates during pregnancy. It is advisable to avoid use unless clearly needed and prescribed by a healthcare professional.

Breast-feeding

Data on the excretion of clathrates in human milk is not available. Caution is recommended when administering to breastfeeding women.

Storage

Store in a cool, dry place away from light. Ensure that it is kept out of reach of children.

Indications

• Used as a disintegrant in tablet formulations
• Enhances the bioavailability of active pharmaceutical ingredients

Dosage

Children: Refer to the specific formulation guidelines, as dosage will vary based on the active ingredient and formulation type.

Adults: Refer to the specific formulation guidelines, as dosage will vary based on the active ingredient and formulation type.

Mechanism of action

Croscarmellose sodium works by swelling and absorbing water when it comes into contact with gastrointestinal fluids. This swelling leads to the rapid disintegration of the tablet or capsule matrix, facilitating the release and absorption of the active pharmaceutical ingredients.

Pharmacodynamics

Croscarmellose sodium is classified as a superdisintegrant. Its ability to rapidly disintegrate solid dosage forms can significantly enhance the dissolution rate of the active ingredient, which is crucial for achieving therapeutic effects in a timely manner.

Pharmacokinetics

Croscarmellose sodium is not absorbed in the gastrointestinal tract and does not exert pharmacological effects in the body. It is considered non-toxic and is excreted unchanged. Its main role is as an excipient, influencing the formulation's characteristics rather than the pharmacokinetics of the active ingredients.

Precautions

• Use with caution in patients with known hypersensitivity to croscarmellose or its components.

Pregnancy

Safety in pregnancy has not been established. Use only if clearly needed.

Breast-feeding

Caution is advised when using during breastfeeding, as safety has not been established.

Storage

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

Formulations

• Powder
• Granules

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

• Contraception
• Management of acne
• Management of hirsutism

Mechanism of action

Drospirenone and ethinyl estradiol in combination suppress the release of follicle stimulating hormone (FSH) and luteinizing hormone (LH), preventing ovulation. Drospirenone also alters cervical mucus consistency, hindering sperm movement, and reducing the likelihood of embryo implantation. Its anti-mineralocorticoid activity, achieved through blocking aldosterone receptors, promotes sodium and water excretion. Furthermore, its antiandrogenic activity inhibits dihydrotestosterone (DHT) binding to its receptor, reducing androgen synthesis in the ovaries, which aids in treating acne and hirsutism.

Pharmacodynamics

Drospirenone inhibits follicle maturation and ovulation, leading to effective pregnancy prevention. Its antiandrogen effects improve conditions like acne and hirsutism. When combined with ethinyl estradiol, it positively influences the plasma lipid profile. Drospirenone is associated with fewer adverse effects typical of progesterone contraceptives, such as breast tenderness and mood swings. However, it may increase the risk of venous thromboembolism and hyperkalemia, especially in smokers or women over 35, necessitating caution in high-risk populations.

Pharmacokinetics

Drospirenone is well-absorbed after oral administration, with peak plasma concentrations usually occurring within 1-2 hours. It has a half-life of approximately 30 hours, allowing for once-daily dosing in combination oral contraceptive formulations. The drug is metabolized in the liver, primarily via cytochrome P450 enzymes, and its metabolites are excreted primarily through urine. Due to its antimineralocorticoid properties, caution is advised in patients with renal impairment or those on medications that may increase potassium levels.

Contra-indications

• Pregnancy
• Severe liver disease
• History of thrombosis or thromboembolic disorders
• Known or suspected breast cancer or other hormone-sensitive malignancies
• Uncontrolled hypertension
• Hyperkalemia

Adverse effects

• Nausea
• Headache
• Breast tenderness
• Mood changes
• Weight gain
• Vaginal bleeding irregularities
• Increased risk of venous thromboembolism

Interactions

• dronedarone+drospirenone: Unknown (increases exposure)
• cobicistat+drospirenone: Unknown (increases exposure)
• crizotinib+drospirenone: Unknown (increases exposure)
• idelalisib+drospirenone: Unknown (increases exposure)
• imatinib+drospirenone: Unknown (increases exposure)
• letermovir+drospirenone: Unknown (increases exposure)
• nilotinib+drospirenone: Unknown (increases exposure)

Precautions

• Monitor for signs of hyperkalemia, especially in patients with renal impairment or those on potassium-sparing diuretics
• Assess risk factors for thromboembolic events, especially in women over 35 years and smokers
• Regular monitoring of blood pressure

Pregnancy

Drospirenone is contraindicated in pregnancy. It should not be used during this time due to potential risks to the fetus.

Breast-feeding

Drospirenone may be excreted in breast milk. Caution is advised when administering to breastfeeding women, and it is recommended to consult healthcare providers.

Storage

Store at room temperature, away from moisture and heat. Keep out of reach of children.

Formulations

• Oral tablets containing drospirenone, often in combination with ethinyl estradiol

Indications

• Iron deficiency anemia
• Chronic blood loss
• Nutritional iron deficiency
• Pregnancy-related anemia

Dosage

Children: Refer to the BNF for Children for specific dosing information as it may vary based on the formulation and clinical context.

Adults: Refer to the BNF for specific dosing information as it may vary based on the formulation and clinical context.

Mechanism of action

Ferric ions participate in various biological processes, including oxygen transport and electron transfer. They facilitate the formation of hemoglobin in red blood cells, allowing for efficient oxygen delivery throughout the body. Ferric compounds can also promote the absorption of iron from the gastrointestinal tract by providing a more bioavailable form of iron.

Pharmacodynamics

Ferric compounds exhibit their effects primarily through the restoration of iron levels in the body. This leads to improved synthesis of hemoglobin and overall enhancement of oxygen-carrying capacity. The pharmacological action is dose-dependent, with higher doses leading to more pronounced effects on hemoglobin levels and erythropoiesis. Additionally, ferric ions can influence various metabolic pathways involved in cellular respiration and energy production.

Pharmacokinetics

Ferric is absorbed in the gastrointestinal tract, with absorption rates influenced by dietary factors and the presence of other substances in the gut. Once absorbed, ferric ions are transported in the bloodstream bound to transferrin, a transport protein. The body regulates iron levels primarily through absorption rather than excretion, and excess iron can be stored in the liver, spleen, and bone marrow. The elimination of ferric compounds is generally slow, as they are incorporated into various biological systems or stored for future use.

Contra-indications

• Hypersensitivity to ferric compounds
• Iron overload conditions such as haemochromatosis or haemosiderosis
• Chronic liver disease
• Active peptic ulcer disease

Adverse effects

• Gastrointestinal disturbances including nausea, vomiting, and constipation
• Diarrhea
• Abdominal pain
• Black stools
• Allergic reactions including rashes and anaphylaxis
• Staining of teeth (with oral formulations)

Interactions

• Antacids may reduce the absorption of oral ferric preparations
• Tetracyclines and quinolone antibiotics may have reduced absorption when taken with iron
• Ascorbic acid may enhance the absorption of iron

Precautions

• Caution in patients with a history of gastrointestinal disease
• Monitor for signs of iron overload in patients receiving repeated doses
• Use with caution in patients with renal impairment

Pregnancy

Ferric compounds are generally considered safe in pregnancy when used as directed to treat iron deficiency, but should be used under medical supervision.

Breast-feeding

Ferric compounds are excreted in breast milk in small amounts, usually considered safe but should be used under medical supervision.

Storage

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

Formulations

• Oral tablets
• Oral solution
• Intravenous injection

Indications

• Ophthalmic solutions
• Topical formulations
• Oral solid dosage forms
• Stabilizer in various pharmaceutical preparations

Dosage

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

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

Mechanism of action

Hydroxypropylcellulose functions primarily as a viscosity-increasing agent. When dissolved in water, it forms a gel-like consistency that helps to stabilize formulations. Its mechanism is related to its ability to create a hydrated film, which can enhance the retention of active ingredients and improve the delivery of medications to the targeted area, particularly in ocular applications.

Pharmacodynamics

The pharmacodynamic properties of hydroxypropylcellulose are primarily related to its physical characteristics rather than specific receptor interactions. It exhibits properties such as gel formation and moisture retention, which can enhance the stability and effectiveness of drug formulations. Its viscosity can influence the release rates of active pharmaceutical ingredients, thereby affecting the overall therapeutic effect.

Pharmacokinetics

Hydroxypropylcellulose is not systemically absorbed when used in pharmaceutical applications, as it acts locally at the site of application. Its pharmacokinetics involves dissolution and gel formation in the presence of water, with no significant metabolic pathways or excretion processes, given its large molecular structure. The duration of action is primarily influenced by the formulation and the concentration used.

Pregnancy

Hydroxypropylcellulose is generally considered safe for use during pregnancy as it is not systemically absorbed. However, it should be used only when clearly needed.

Breast-feeding

Hydroxypropylcellulose is not absorbed systemically and is considered safe for use during breastfeeding.

Storage

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

Formulations

• Ophthalmic solutions
• Topical gels
• Oral capsules
• Powders for reconstitution

Dosage

Children: Refer to product-specific guidelines for application instructions, as dosing is not applicable.

Adults: Refer to product-specific guidelines for application instructions, as dosing is not applicable.

Mechanism of action

Lacquer works primarily by forming a protective film on the surface where it is applied. The resins in lacquer undergo a curing process, which involves evaporation of solvents and hardening of the film, resulting in a durable, glossy finish. This film provides a barrier against moisture, dirt, and physical wear, thus enhancing the longevity of the underlying material.

Pharmacodynamics

As lacquer is not a pharmaceutical agent, it does not have pharmacodynamics in the same way that drugs do. However, the protective properties of lacquer can be understood in terms of its ability to prevent damage to surfaces, reduce absorption of contaminants, and improve aesthetic qualities.

Pharmacokinetics

Lacquer does not have pharmacokinetics as it is not intended for systemic absorption or therapeutic use in the human body. Instead, its application involves surface interaction, where the lacquer forms a film that solidifies and adheres to the substrate without being absorbed.

Pregnancy

Safety during pregnancy has not been established. Use with caution.

Breast-feeding

Lacquer is not recommended during breastfeeding due to potential exposure to the infant.

Storage

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

Indications

• Lactose intolerance
• As a filler or excipient in pharmaceutical formulations

Dosage

Children: Refer to the BNF for Children for specific dosing information based on age and clinical context.

Adults: Refer to the BNF for specific dosing information based on clinical context.

Mechanism of action

Lactose is metabolized in the intestine by the enzyme lactase into its constituent monosaccharides, glucose and galactose. In individuals with lactase deficiency, unabsorbed lactose passes into the colon, where it is fermented by bacteria, leading to gas production and osmotic effects that contribute to diarrhea.

Pharmacodynamics

The pharmacodynamics of lactose are primarily related to its effects on gastrointestinal function. In healthy individuals, lactose is effectively broken down into glucose and galactose, which are absorbed and utilized for energy. In individuals with lactose intolerance, the unabsorbed lactose can cause osmotic diarrhea and colonic fermentation, leading to discomfort and symptoms associated with lactose intolerance.

Pharmacokinetics

Lactose is not absorbed in the gastrointestinal tract until it is hydrolyzed into glucose and galactose by lactase. The absorption of glucose and galactose occurs in the small intestine. The half-life is not applicable as lactose is not typically administered as a medication but is rather ingested as a natural component of food. Its metabolism primarily occurs in the intestine.

Adverse effects

• Bloating
• Diarrhea
• Abdominal pain
• Flatulence

Precautions

• Use with caution in patients with lactose intolerance.
• Consider potential for gastrointestinal upset in sensitive individuals.

Pregnancy

Lactose is generally considered safe for use during pregnancy. However, consult a healthcare professional for individual advice.

Breast-feeding

Lactose is safe to use while breastfeeding, as it is a natural sugar present in breast milk.

Storage

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

Formulations

• Powder
• Granules
• Tablets
• Syrup

Indications

• Folate deficiency
• Homocystinuria
• Prevention of neural tube defects in pregnancy
• Support in conditions associated with elevated homocysteine levels

Dosage

Adults: Refer to the BNF for specific adult dosing guidelines.

Mechanism of action

Levomefolic acid facilitates the methylation of homocysteine to methionine by acting as a methyl donor in a reaction mediated by vitamin B12-dependent methionine synthase. Following this conversion, methionine is transformed into S-adenosylmethionine (SAMe), which is integral to numerous methylation reactions in the body, including those involved in neurotransmitter synthesis.

Pharmacodynamics

Levomefolate is crucial for one-carbon metabolism, influencing several cellular functions such as DNA synthesis, regulation of gene expression, and amino acid metabolism. Its role as a methyl donor is essential for the production of monoamine neurotransmitters, and it also aids in the formation of red blood cells. Additionally, levomefolate's ability to cross the blood-brain barrier allows it to exert effects on neurological functions and mood regulation.

Pharmacokinetics

The pharmacokinetics of levomefolate involve its absorption, distribution, metabolism, and excretion. After administration, levomefolate is absorbed in the gastrointestinal tract and can readily cross the blood-brain barrier. It undergoes metabolic processes that facilitate its biological activity. Its elimination half-life and specific metabolic pathways may vary based on individual physiological conditions and dietary factors. Detailed pharmacokinetic parameters should be referenced from specific clinical studies or drug databases.

Pregnancy

Levomefolate is generally considered safe during pregnancy as it is essential for fetal development, particularly in the prevention of neural tube defects.

Breast-feeding

Levomefolate is excreted in breast milk. The effects on nursing infants are unknown, but it is considered safe for use during breastfeeding.

Storage

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

Formulations

• Tablets
• Capsules
• Oral solutions

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

• Constipation
• Bowel preparation for diagnostic procedures (e.g., colonoscopy)

Dosage

Children: For children, macrogol is typically used at a dose of 0.5 to 1 g/kg per day, not exceeding 17 g per day, depending on the child's age and condition. Refer to the BNF for Children for detailed pediatric dosing guidance.

Adults: Typical adult dosing for constipation is 8.4 grams of macrogol powder dissolved in water, taken once daily. For bowel preparation, specific dosing regimens may vary, and it is essential to follow product instructions or medical advice.

Mechanism of action

Macrogol works as an osmotic agent, drawing water into the bowel lumen through osmosis. This increased water content softens the stool, making it easier to pass. The presence of macrogol in the intestine increases the volume and viscosity of the stool, stimulating peristalsis and facilitating bowel evacuation.

Pharmacodynamics

Macrogol's laxative effect is dose-dependent, with higher doses generally resulting in more significant bowel movement stimulation. It is not absorbed systemically, which minimizes potential side effects and interactions. The osmotic effect leads to an increase in intraluminal pressure and stool volume, contributing to effective evacuation.

Pharmacokinetics

Macrogol is largely non-absorbed in the gastrointestinal tract, which allows it to exert its effects locally within the bowel. Due to its high molecular weight, it remains in the intestinal lumen, where it facilitates water retention. Elimination occurs through feces, as it is not metabolized by the body.

Pregnancy

Macrogol can be used during pregnancy if necessary, but caution should be exercised and medical advice sought.

Breast-feeding

Macrogol is generally considered safe to use during breastfeeding.

Storage

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

Indications

• Used as an excipient in tablet formulations
• Used as a bulking agent in capsule formulations
• Used in food products as a thickener or stabilizer

Dosage

Children: Refer to specific product guidelines as dosage will depend on the formulation and the active ingredients.

Adults: Refer to specific product guidelines as dosage will depend on the formulation and the active ingredients.

Mechanism of action

Microcrystalline cellulose acts as a non-digestible filler that enhances the flow properties of powders during the manufacturing of tablets and capsules. It does not have a direct pharmacological action on the body but ensures that the active ingredients are effectively delivered to the patient.

Pharmacodynamics

As a non-active ingredient, microcrystalline cellulose does not exert pharmacodynamic effects typical of active pharmaceutical ingredients. Its primary role is to provide a stable and consistent matrix for the drug, facilitating the release of the active compound once ingested.

Pharmacokinetics

Microcrystalline cellulose is not absorbed in the gastrointestinal tract; it passes through the digestive system largely unchanged. It adds bulk to the stool, which may aid in promoting regular bowel movements. The substance is excreted in feces, where it contributes to dietary fiber intake.

Pregnancy

Data regarding the use of microcrystalline cellulose during pregnancy is limited. It is advisable to consult with healthcare professionals before use.

Breast-feeding

Microcrystalline cellulose is considered safe during breastfeeding, as it is not absorbed systemically.

Storage

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

Indications

• Enhanced absorption of poorly soluble drugs
• Improved therapeutic effectiveness of various medications

Dosage

Children: Refer to specific drug formulations for dosing information, as dosages can vary widely based on the active ingredient.

Adults: Refer to specific drug formulations for dosing information, as dosages can vary widely based on the active ingredient.

Mechanism of action

Micronization itself does not alter the pharmacological activity of the drug; rather, it enhances the drug's absorption characteristics. This is particularly significant for drugs that are poorly soluble, as increased absorption can lead to more effective therapeutic outcomes.

Pharmacodynamics

The pharmacodynamics of micronized drugs remain consistent with the pharmacological profile of the active ingredient. Micronized drugs often exhibit enhanced onset of action due to increased absorption rates, leading to quicker therapeutic effects. However, the specific effects will depend on the drug and its mechanism of action.

Pharmacokinetics

Micronization can significantly influence the pharmacokinetics of a drug by improving its absorption in the gastrointestinal tract. This may lead to increased peak plasma concentrations and altered time to peak effect. The elimination half-life and volume of distribution may remain unchanged, but the overall bioavailability may be improved.

Pregnancy

Micronized formulations should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Consultation with a healthcare provider is recommended.

Breast-feeding

Caution is advised when using micronized drugs while breastfeeding. The effects on the infant should be considered, and consultation with a healthcare provider is recommended.

Storage

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

Dosage

Children: Refer to BNF for Children for specific recommendations regarding the consumption of orange juice in children.

Adults: There is no standard dosage for orange juice as it is typically consumed as a beverage. Moderation is advised, especially for individuals on certain medications.

Mechanism of action

The exact mechanism of action of orange juice is not fully understood, but it is known to contain compounds that can influence the metabolism of certain drugs. For instance, it may affect the activity of cytochrome P450 enzymes, particularly CYP3A4, which can alter the pharmacokinetics of medications.

Pharmacodynamics

Orange juice is known to enhance the bioavailability of certain nutrients and may influence the pharmacological effects of some drugs. Its high vitamin C content contributes to various physiological functions, including antioxidant activity, which may indirectly support overall health.

Pharmacokinetics

The pharmacokinetics of orange juice itself are not extensively studied, but it is generally absorbed well through the gastrointestinal tract. The compounds in orange juice can affect the absorption and metabolism of medications, leading to varied clinical effects depending on the drug in question.

Interactions

• orange juice + celiprolol: Unknown (decreases exposure)

Formulations

• juice
• whole fruit

Mechanism of action

Oxides do not have a single mechanism of action as they are a broad category of compounds. However, in general, metal oxides can exhibit catalytic properties, while non-metal oxides may participate in biochemical reactions by forming acids or bases upon dissolution in water.

Pharmacodynamics

The pharmacodynamics of oxides depend on the specific type of oxide and its interaction with biological systems. For instance, metal oxides may have antimicrobial properties, while certain non-metal oxides can influence metabolic pathways through their acid-base chemistry. The effects vary widely, necessitating specific studies for each oxide's role in therapeutic contexts.

Pharmacokinetics

The pharmacokinetics of oxides are also variable. Many metal oxides are poorly soluble and thus have limited absorption when ingested. Non-metal oxides, such as carbon dioxide, can be readily absorbed and utilized in metabolic processes. The distribution, metabolism, and excretion of oxides depend on their chemical form and the biological system in which they are involved.

Pregnancy

Not applicable as oxide is not a drug but a class of chemical compounds.

Breast-feeding

Not applicable as oxide is not a drug but a class of chemical compounds.

Storage

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

Indications

• Used as an excipient in drug formulations
• Pleurodesis for the management of recurrent pleural effusions

Dosage

Children: Refer to specific guidelines for paediatric use, as dosing may differ based on age and clinical condition.

Adults: Refer to specific guidelines for the appropriate dosage in pleurodesis and other applications, as it may vary based on clinical context.

Mechanism of action

Talc exhibits very good absorptive properties, allowing it to absorb moisture and other substances effectively. This characteristic is particularly useful in pharmaceutical formulations, where it may enhance the stability and texture of the drug product.

Pharmacodynamics

Talc's primary pharmacodynamic effect is its ability to act as an inert filler and bulking agent in pharmaceutical preparations. It does not have any intrinsic pharmacological activity but serves to improve the physical properties of formulations, such as flowability and compressibility.

Pharmacokinetics

Talc is not absorbed systemically when used as an excipient or in medical procedures. Its effects are local, and it remains in the site of application, where it functions primarily as a mechanical agent. The pharmacokinetics of talc in the context of its use in pleurodesis involves its ability to promote adhesion of the pleural surfaces, thereby preventing fluid accumulation.

Pregnancy

Talc is classified as a substance with minimal systemic absorption, but safety during pregnancy has not been well established. Consult relevant guidelines.

Breast-feeding

Talc is not expected to be absorbed in significant amounts; however, caution is advised and consult guidelines.

Storage

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

Indications

• Orthopedic implants
• Dental implants
• Prosthetic devices
• Surgical instruments

Mechanism of action

Titanium does not have a specific mechanism of action as it is not a drug in the traditional sense. Instead, its biocompatibility allows it to integrate with biological tissues without eliciting significant immune responses, making it suitable for use in implants and prosthetic devices. The presence of titanium ions can influence biological processes, including cell proliferation and differentiation.

Pharmacodynamics

Titanium itself does not exhibit pharmacodynamics as it is not administered as a drug. Its interactions within biological systems are primarily mechanical and structural, providing support and stability in orthopedic and dental applications. The biocompatibility of titanium allows for favorable tissue integration and reduced rejection rates compared to other materials.

Pharmacokinetics

As titanium is not a pharmacological agent, traditional pharmacokinetic parameters such as absorption, distribution, metabolism, and excretion do not apply. Titanium is typically utilized in solid forms, such as implants, where it remains localized and does not undergo metabolism or systemic circulation.

Pregnancy

There is limited data on the use of titanium during pregnancy. Consult a healthcare professional before use.

Breast-feeding

There is limited data on the excretion of titanium in breast milk. Consult a healthcare professional before use.

Storage

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

Pregnancy

No specific data available, consult a healthcare professional.

Breast-feeding

No specific data available, consult a healthcare professional.

Storage

Store in a cool, dry place away from light.

Mechanism of action

Ethinylestradiol is a synthetic estrogenic compound. Use of estrogens have a number of effects on the body including reduced bone density. Combined oral contraceptives suppress ovulation by suppressing gonadotrophic hormone, thickening cervical mucus to prevent the travel of sperm, and preventing changes in the endometrium required for implantation of a fertilized egg. Ethinylestradiol decreases luteinizing hormone, decreasing vascularity in the endometrium. It also increases sex hormone binding globulin. Endogenous estrogens are largely responsible for the development and maintenance of the female reproductive system and secondary sexual characteristics. Although circulating estrogens exist in a dynamic equilibrium of metabolic interconversions, estradiol is the principal intracellular human estrogen and is substantially more potent than its metabolites estrone and estriol at the receptor level. ... After menopause, most endogenous estrogen is produced by conversion of androstenedione, secreted by the adrenal cortex, to estrone by peripheral tissues. Thus, estrone and the sulfate conjugated form, estrone sulfate, are the most abundant circulating estrogens in postmenopausal women. The pharmacologic effects of ethinyl estradiol are similar to those of endogenous estrogens. Estrogens act through binding to nuclear receptors in estrogen-responsive tissues. To date, two estrogen receptors have been identified. These vary in proportion from tissue to tissue. Circulating estrogens modulate the pituitary secretion of the gonadotropins, luteinizing hormone (LH) and follicle stimulating hormone (FSH) through a negative feedback mechanism. Estrogens act to reduce the elevated levels of these hormones seen in postmenopausal women. Estrogens have an important role in the reproductive, skeletal, cardiovascular, and central nervous systems in women, and act principally by regulating gene expression. Biologic response is initiated when estrogen binds to a ligand-binding domain of the estrogen receptor resulting in a conformational change that leads to gene transcription through specific estrogen response elements (ERE) of target gene promoters; subsequent activation or repression of the target gene is mediated through 2 distinct transactivation domains (ie, AF-1 and AF-2) of the receptor. The estrogen receptor also mediates gene transcription using different response elements (ie, AP-1) and other signal pathways. Recent advances in the molecular pharmacology of estrogen and estrogen receptors have resulted in the development of selective estrogen receptor modulators (eg, clomiphene, raloxifene, tamoxifen, toremifene), agents that bind and activate the estrogen receptor but that exhibit tissue-specific effects distinct from estrogen. Tissue-specific estrogen-agonist or -antagonist activity of these drugs appears to be related to structural differences in their estrogen receptor complex (eg, specifically the surface topography of AF-2 for raloxifene) compared with the estrogen (estradiol)-estrogen receptor complex. A second estrogen receptor also has been identified, and existence of at least 2 estrogen receptors (ER-alpha, ER-beta) may contribute to the tissue-specific activity of selective modulators. While the role of the estrogen receptor in bone, cardiovascular tissue, and the CNS continues to be studied, emerging evidence indicates that the mechanism of action of estrogen receptors in these tissues differs from the manner in which estrogen receptors function in reproductive tissue. /Estrogen General Statement/ Intracellular cytosol-binding proteins for estrogens have been identified in estrogen-responsive tissues including the female genital organs, breasts, pituitary, and hypothalamus. The estrogen-binding protein complex (ie, cytosol-binding protein and estrogen) distributes into the cell nucleus where it stimulates DNA, RNA, and protein synthesis. The presence of these receptor proteins is responsible for the palliative response to e

Pharmacodynamics

Ethinylestradiol is a synthetic estrogen that decreases luteinizing hormone to decrease endometrial vascularization, and decreases gonadotrophic hormone to prevent ovulation. It has a long duration of action as it is taken once daily, and a wide therapeutic index as overdoses are generally not associated with serious adverse effects. Patients should be counselled regarding the risks of thrombotic events.

Mechanism of action

Drospirenone and ethinyl estradiol in combination suppress the release of follicle stimulating hormone (FSH) and luteinizing hormone (LH), preventing ovulation. Other changes induced by this drug which may aid in the prevention of pregnancy include alterations in cervical mucus consistency, hindering sperm movement, and lowering the chance of embryo implantation. Drospirenone is an analog of the diuretic spironolactone, which exerts anti-mineralocorticoid activity, blocking aldosterone receptors, which increases sodium and water excretion. Studies in animals have demonstrated that drospirenone administration leads to antiandrogenic activity. This activity helps to oppose the effects of naturally occurring androgens, inhibiting the binding of dihydrotestosterone (DHT) to its receptor, and preventing androgen synthesis in the ovaries, helping to treat acne and hirsutism. Drospirenone may also decrease the level of edema in sebaceous follicle during the second half of the menstrual cycle, when acne often appears. Combination oral contraceptives (COCs) act by suppression of gonadotropins. Although the primary mechanism of this action is inhibition of ovulation, other alterations include changes in the cervical mucus (which increases the difficulty of sperm entry into the uterus) and the endometrium (which reduces the likelihood of implantation). Drospirenone is a spironolactone analogue with antimineralocorticoid activity. Preclinical studies in animals and in vitro have shown that drospirenone has no androgenic, estrogenic, glucocorticoid, or antiglucocorticoid activity. Preclinical studies in animals have also shown that drospirenone has antiandrogenic activity. Acne vulgaris is a skin condition with a multifactorial etiology including androgen stimulation of sebum production. While the combination of ethinyl estradiol and drospirenone increases sex hormone binding globulin (SHBG) and decreases free testosterone, the relationship between these changes and a decrease in the severity of facial acne in otherwise healthy women with this skin condition has not been established. The impact of the antiandrogenic activity of drospirenone on acne is not known. .... The pharmacological properties of drospirenone were investigated in vitro by receptor binding and transactivation experiments and in vivo in appropriate animal models. In qualitative agreement with progesterone, the compound binds strongly to the progesterone and the mineralocorticoid receptor and with lower affinity to androgen and glucocorticoid receptors. There is no detectable binding to the estrogen receptor. Steroid hormone agonistic and antagonistic activities of progesterone and drospirenone were compared in transactivation experiments. Individual steroid hormone receptors were artificially expressed together with a reporter gene in appropriate cell lines. Both hormones were unable to induce any androgen receptor-mediated agonistic activity. Rather, both progesterone and drospirenone distinctly antagonized androgen-stimulated transcriptional activation. Likewise, both compounds only very weakly activated the mineralocorticoid receptor but showed potent aldosterone antagonistic activity. Drospirenone did not induce glucocorticoid receptor-driven transactivation. Progesterone was a weak agonist in this respect. Drospirenone exerts potent progestogenic and antigonadotropic activity which was studied in various animal species. It efficiently promotes the maintenance of pregnancy in ovariectomized rats, inhibits ovulation in rats and mice and stimulates endometrial transformation in the rabbit. Furthermore, drospirenone shows potent antigonadotropic, i.e., testosterone-lowering activity in male cynomolgus monkeys. The progestogenic potency of drospirenone was found to be in the range of that of norethisterone acetate. The majority of clinically used progestogens are androgenic. Drospirenone, like progesterone, has no androgenic but rather an antiandrogenic effect. This pro

Pharmacodynamics

Drospirenone inhibits the maturation of follicles and inhibits ovulation, preventing pregnancy. It has antiandrogen effects, improving acne and hirsutism. When combined with ethinyl estradiol, it has been shown to have favorable effects on the plasma lipid profile. Due to its similarity to naturally occurring progesterone, drospirenone is thought to be associated with a lower incidence of progesterone contraceptive related adverse effects, such as breast tenderness and mood swings. **A note on venous thromboembolism risk and antimineralcorticoid effects** As with other oral contraceptives, the risk of venous thromboembolism and cardiovascular events may be increased when drospirenone is taken. The risk is especially higher in smokers and women aged 35 and older. Women taking this drug should be advised not to smoke. In addition, drospirenone, due to its antimineralcorticoid effects, may increase the risk of hyperkalemia. Patients at high risk for hyperkalemia should not be administered this drug. Consult the official prescribing information for detailed and updated information on the cardiovascular and other risks associated with drospirenone use.

Mechanism of action

Levomefolic acid plays a critical role in methylating homocysteines into methionine by acting as a methyl donor in a reaction catalyzed by vitamine B12-dependent methionine synthase. Homocysteine must either be further metabolized via transulfuration to become cysteine, taurine, and glutathione via a B6-dependent process, or re-methylated to become methionine again. Methionine formed from remethylation of homocysteine by levomefolic acid forms the downstream metabolite S-adenosylmethionine (SAMe), which is involved in numerous biochemical methyl donation reactions, including reactions forming monoamine neurotransmitters. Studies suggest that high plasma levels of homocysteine is associated with increased incidences of arterial plaque formation.

Pharmacodynamics

Levomefolic acid is an active metabolite of folic acid and a methyl group donor in one-carbon metabolism reactions. It regulates important cellular functions such as DNA biosynthesis, gene expression regulation, amino acid synthesis and metabolism, and myelin synthesis and repair. As a only form of folate that can cross the blood-brain barrier, it acts as a cofactor in the production of monoamine neurotransmitters such as dopamine, serotonin and norepinephrine. Levomefolic acid is also involved in red blood cell formation.

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

It has very good absorptive properties.