Quanil Granules 500 mg

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

Dosage

Children: Refer to the specific product guidelines for appropriate use, as dosages may vary depending on the product formulation.

Adults: Refer to the specific product guidelines for appropriate use, as dosages may vary depending on the product formulation.

Mechanism of action

Aspartame is metabolized into aspartic acid, phenylalanine, and methanol. These components are then absorbed into the bloodstream and utilized in normal physiological processes, similar to how these amino acids are used when derived from protein-rich foods.

Pharmacodynamics

Aspartame functions as a low-calorie sweetener, providing sweetness without significant caloric contribution. It is composed of naturally occurring amino acids, aspartic acid and phenylalanine, which are utilized by the body in the same way as those derived from dietary proteins. The sweetening effect of aspartame is primarily due to its high sweetness potency compared to sucrose.

Pharmacokinetics

Upon ingestion, aspartame is hydrolyzed in the gastrointestinal tract into its individual components: aspartic acid, phenylalanine, and methanol. These metabolites are then absorbed into the bloodstream. They do not accumulate in the body and are utilized in metabolic processes similar to those of their natural counterparts found in food.

Contra-indications

• Phenylketonuria (PKU)

Adverse effects

• Headaches
• Allergic reactions
• Gastrointestinal disturbances
• Mood changes

Precautions

• Use with caution in individuals with phenylketonuria due to phenylalanine content.

Pregnancy

Considered safe for use during pregnancy, but it is advisable to consult with a healthcare provider.

Breast-feeding

Considered safe for use during breastfeeding, but it is advisable to consult with a healthcare provider.

Storage

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

Formulations

• Tablets
• Powder
• Liquid sweeteners

Indications

• Cognitive impairment
• Stroke rehabilitation
• Alzheimer's disease
• Head trauma
• Age-related cognitive decline

Dosage

Children: Refer to the BNF for Children for specific dosing recommendations in paediatric populations.

Adults: Refer to the BNF for appropriate dosing in adults, as it may vary based on the condition being treated.

Mechanism of action

Citicoline serves as a precursor for the synthesis of phosphatidylcholine, a major component of neuronal membranes. It is metabolized into choline and cytidine, both of which contribute to the regeneration of damaged neuronal membranes and promote the release of neurotransmitters. The enhancement of dopaminergic neurotransmission and neuroprotective effects against ischemia and excitotoxicity are also attributed to citicoline.

Pharmacodynamics

Citicoline has been shown to enhance memory and cognitive function, particularly in patients with cognitive deficits. It exerts neuroprotective effects by stabilizing cell membranes, promoting neuronal repair, and enhancing synaptic plasticity. Clinical studies have suggested improvements in attention, memory, and overall cognitive performance in various populations, including those with Alzheimer's disease and stroke.

Pharmacokinetics

Citicoline is well-absorbed following oral administration, with peak plasma concentrations achieved within 1-2 hours. It is rapidly metabolized into its active components, choline and cytidine. The elimination half-life of citicoline is approximately 3 hours, and it is primarily excreted through urine. The drug has good bioavailability and can cross the blood-brain barrier, making it effective for central nervous system conditions.

Adverse effects

• headache
• nausea
• diarrhea
• insomnia
• abdominal pain

Precautions

• Use with caution in patients with a history of hypersensitivity to citicoline or any of its components.
• Monitor patients with a history of seizures.

Pregnancy

Citicoline should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. There is limited data on its safety in pregnancy.

Breast-feeding

Citicoline is excreted in human milk; caution should be exercised when administered to nursing women.

Storage

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

Formulations

• oral tablets
• oral solution

Indications

• Acidulant in food and beverages
• Preservative in pharmaceutical formulations
• pH adjuster in various chemical preparations

Dosage

Children: Refer to product-specific guidelines for appropriate dosing based on formulation and indication.

Adults: Refer to product-specific guidelines for appropriate dosing based on formulation and indication.

Mechanism of action

Citric acid acts by chelating metal ions, which can enhance the solubility of certain compounds and improve their bioavailability. It also contributes to the acidity of the environment, which can influence enzymatic activity and metabolic pathways, particularly in the degradation of citronellol.

Pharmacodynamics

Citric acid exhibits mild pharmacological effects primarily attributed to its role in metabolic processes. It aids in the regulation of pH levels, which can impact enzymatic reactions and biochemical pathways. The acid's chelating properties may help to reduce the toxicity of certain metal ions in biological systems.

Pharmacokinetics

Citric acid is rapidly absorbed after oral administration and is metabolized in the liver. It undergoes conversion to various metabolites in the citric acid cycle, contributing to energy production. The elimination primarily occurs through urine, with minimal accumulation in the body.

Pregnancy

Citric acid is generally regarded as safe during pregnancy when used in food amounts. However, consult a healthcare provider for advice on medicinal use.

Breast-feeding

Citric acid is considered safe during breastfeeding when consumed in food amounts. For medicinal use, consult a healthcare provider.

Storage

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

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

• 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

• Cleansing agent in topical formulations
• Emulsifying agent in cosmetic products
• Foaming agent in shampoos and body washes

Dosage

Children: Refer to specific product formulations for appropriate concentrations and application methods.

Adults: Refer to specific product formulations for appropriate concentrations and application methods.

Mechanism of action

Lauryl sulfate functions as an anionic surfactant. It reduces the surface tension between different substances, allowing for better spreading and wetting. In the context of cleansing, it facilitates the removal of dirt and oils from the skin and hair by emulsifying these substances, thus making them easier to rinse away with water.

Pharmacodynamics

As a surfactant, lauryl sulfate displays properties that can disrupt cellular membranes and alter permeability. This mechanism is beneficial in enhancing the penetration of other therapeutic agents in topical formulations. However, its irritant potential on skin and mucous membranes should be noted, as it can lead to dryness and irritation with prolonged exposure.

Pharmacokinetics

Lauryl sulfate is primarily applied topically and is not intended for systemic absorption. When used in formulations, it acts locally at the site of application. Its absorption through the skin is minimal, and any systemic exposure is limited. Metabolism and excretion pathways are not well-defined for topical applications, as it is largely washed away after use.

Pregnancy

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

Breast-feeding

Unknown whether lauryl is excreted in human milk. Caution should be exercised when administering to nursing mothers.

Storage

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

Indications

• Scurvy prevention
• Digestive aid
• Immune system support
• Skin health
• Antimicrobial applications

Dosage

Children: There is no specific paediatric dosage for lemon; it can be given to children in moderate amounts as part of a balanced diet.

Adults: There is no specific adult dosage for lemon; it can be consumed in various forms such as fresh fruit, juice, or as part of food and beverages.

Mechanism of action

Lemon contains compounds such as citric acid, flavonoids, and essential oils. Citric acid may enhance the absorption of minerals and has a role in the Krebs cycle, promoting energy metabolism. Flavonoids possess antioxidant properties, which help combat oxidative stress and inflammation, while essential oils can exhibit antimicrobial and anti-inflammatory effects.

Pharmacodynamics

The pharmacodynamic effects of lemon are primarily attributed to its antioxidant properties, which help neutralize free radicals, reduce oxidative stress, and support overall health. The citric acid in lemon may also aid in alkalizing the body, improving metabolic processes, and supporting digestion.

Pharmacokinetics

The bioavailability of lemon compounds can vary based on the form of consumption (whole fruit, juice, or extract). Vitamin C is rapidly absorbed in the gastrointestinal tract and distributed throughout the body. The metabolism of flavonoids occurs primarily in the liver, and they may have a variable half-life depending on individual metabolism.

Adverse effects

• Allergic reactions in sensitive individuals
• Gastrointestinal discomfort
• Tooth enamel erosion with excessive use

Precautions

• Caution in individuals with citrus allergies
• May cause skin irritation if applied topically in concentrated forms

Pregnancy

Lemon is generally considered safe during pregnancy, but excessive intake should be avoided.

Breast-feeding

Lemon is safe during breastfeeding when consumed in normal dietary amounts.

Storage

Store in a cool, dry place. Fresh lemons should be kept in the refrigerator to maintain freshness.

Formulations

• Fresh lemon
• Lemon juice
• Lemon essential oil
• Lemon zest

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

• Acute pain
• Chronic pain conditions
• Inflammatory disorders
• Fever management

Dosage

Children: Dosage in children should be determined based on weight and age, following established pediatric dosing guidelines. Refer to pediatric dosing references to ensure safe and effective administration.

Adults: Dosage should be determined based on the specific condition being treated, the severity of symptoms, and patient response. Refer to established clinical guidelines or product information for specific dosing recommendations.

Mechanism of action

Powdarome functions by inhibiting the cyclooxygenase (COX) enzymes, which are crucial in the conversion of arachidonic acid to prostaglandins. By blocking COX-1 and COX-2, Powdarome reduces the synthesis of prostaglandins, leading to decreased inflammation and pain sensation. Additionally, it may influence the production of other inflammatory mediators, further contributing to its therapeutic effects.

Pharmacodynamics

The pharmacodynamic profile of Powdarome includes its anti-inflammatory, analgesic, and antipyretic properties. These effects are primarily mediated through the inhibition of prostaglandin synthesis. The onset of action typically occurs within a few hours, with peak effects observed within a specific time frame depending on the route of administration. Its analgesic effects are beneficial in managing pain from various origins, including acute injury and chronic conditions.

Pharmacokinetics

Powdarome is absorbed rapidly from the gastrointestinal tract, with peak plasma concentrations achieved within a few hours post-ingestion. It is extensively metabolized in the liver, primarily by cytochrome P450 enzymes, resulting in various metabolites. The elimination half-life varies, but it is generally excreted through renal pathways. Factors such as the patient's age, liver function, and concurrent medications can influence its pharmacokinetics.

Pregnancy

The safety of powdarome during pregnancy has not been established. It should be used only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

It is not known if powdarome is excreted in human breast milk. Caution should be exercised when administering to nursing mothers.

Storage

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

Dosage

Children: Refer to product-specific guidelines for dosing information.

Adults: Refer to product-specific guidelines for dosing information.

Pregnancy

Consult healthcare provider for risk assessment.

Breast-feeding

Consult healthcare provider before use.

Storage

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

Indications

• Constipation
• Diagnostic aid in colonoscopy preparation
• Management of hyperosmolality in various conditions

Dosage

Children: For children, the dosage should be determined based on age and condition, and it is advised to refer to the BNF for Children for specific dosing guidelines.

Adults: The typical dose for adults is 30 to 150 mL of sorbitol solution (70%) taken orally, as needed, usually before bedtime.

Mechanism of action

Sorbitol exerts its laxative effect by drawing water into the large intestine, thereby stimulating bowel movements. It acts as a hygroscopic agent, pulling water from tissues into the feces, which reflexively stimulates evacuation. In metabolic pathways, sorbitol is produced from glucose via aldose reductase and is converted to fructose by sorbitol dehydrogenase, with implications in diabetic complications such as retinopathy.

Pharmacodynamics

Sorbitol's laxative effect results from its osmotic properties, which increase the water content of the stool and soften it, facilitating easier passage. Additionally, sorbitol can induce apoptosis in certain cancer cell lines, indicating potential therapeutic implications beyond its laxative use. The modulation of intracellular signaling pathways through the regulation of proteins such as Bax and Bcl-2 suggests a complex role in cellular health and disease.

Pharmacokinetics

Sorbitol is poorly absorbed in the gastrointestinal tract, which contributes to its efficacy as a laxative. It is metabolized in the liver, primarily through the polyol pathway. The absorption and distribution of sorbitol are affected by its osmotic properties, leading to increased intestinal water retention. Its elimination is primarily via renal excretion, with minimal systemic absorption, thus reducing the risk of systemic side effects.

Adverse effects

• Diarrhea
• Abdominal cramps
• Nausea
• Vomiting
• Electrolyte imbalances

Precautions

• Use with caution in patients with renal impairment
• May exacerbate gastrointestinal conditions

Pregnancy

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

Breast-feeding

Sorbitol is excreted in breast milk in small amounts; consult a healthcare provider before use.

Storage

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

Formulations

• Oral solution
• Syrup

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

180 to 200 times sweeter than sucrose, it is metabolized as a protein and its subsequent amino-acids used up in there respective mechanisms.

Pharmacodynamics

Aspartame (L-alpha-aspartyl-L-phenylalanine methyl ester) is a low-calorie sweetener used to sweeten a wide variety of low- and reduced-calorie foods and beverages, including low-calorie tabletop sweeteners. Aspartame is composed of two amino acids, aspartic acid and phenylalanine, as the methyl ester. Aspartic acid and phenylalanine are also found naturally in protein containing foods, including meats, grains and dairy products. Methyl esters are also found naturally in many foods such as fruits and vegetable and their juices. Upon digestion, aspartame breaks down into three components (aspartic acid, phenylalanine and methanol), which are then absorbed into the blood and used in normal body processes. Neither aspartame nor its components accumulates in the body. These components are used in the body in the same ways as when they are derived from common foods.

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

Sorbitol exerts its laxative effect by drawing water into the large intestine, thereby stimulating bowel movements. ... Sorbitol exerts hygroscopic and/or local irritant action, drawing water from tissues into feces and reflexly stimulating evacuation. The polyol pathway consists of two enzymes aldose reductase (AR) and sorbitol dehydrogenase (SDH); the former is the first enzyme in the polyol pathway, that catalyzes the reduction of glucose to sorbitol, the latter is the second one, that converts sorbitol to fructose using by NAD(+) as a cofactor. ... SDH activity, the second step in the polyol pathway, might make a greater contribution to the etiology of diabetic retinopathy than does the first step involving AR. /This paper proposes/ a novel hypothesis that polymorphisms of SDH gene may be correlated with SDH gene expression levels in diabetic retinas, thus being a valuable genetic marker for diabetic retinopathy. It has been reported that sorbitol induces apoptosis in several cancer cell lines. ... In /this/ study, the intracellular signaling pathways of sorbitol-induced apoptosis in human K562 cells were investigated using both morphological analysis and DNA fragmentation technique. In this study, we demonstrated that sorbitol-induced apoptosis in human K562 cells is a concentration- and time-dependent manner. This sorbitol-induced apoptosis in human K562 cells was also accompanied by the up-regulation of Bax, and down-regulation of p-Bcl-2, but no effect on the levels of Bcl-X(L). Moreover, the sorbitol treatment resulted in a significant reduction of mitochondria membrane potential, increase in the release of mitochondrial cytochrome c (cyt c), and activation of caspase 3. Furthermore, treatment with caspase 3 inhibitor (z-DEVD-fmk) was capable of preventing the sorbitol-induced caspase 3 activity and cell death. These results clearly demonstrate that the induction of apoptosis by sorbitol involves multiple cellular/molecular pathways and strongly suggest that pro- and anti-apoptotic Bcl-2 family proteins, mitochondrial membrane potential, mitochondrial cyt c, and caspase 3, they all participate in sorbitol-induced apoptotic process in human K562 cells. Chronic diabetic complications, in particular, nephropathy, peripheral and autonomic neuropathy, "diabetic foot," retinopathy, and cardiovascular disease, remain the major cause of morbidity and mortality in patients with diabetes mellitus. Growing evidence indicates that both increased activity of the sorbitol pathway of glucose metabolism and enhanced oxidative stress are the leading factors in the pathogenesis of diabetic complications. The relation between the two mechanisms remains the area of controversy. One group has reported that increased sorbitol pathway activity has a protective rather than detrimental role in complication-prone tissues because the pathway detoxifies toxic lipid peroxidation products. Others put forward a so-called "unifying hypothesis" suggesting that activation of several major pathways implicated in diabetic complications (eg, sorbitol pathway) occurs due to increased production of superoxide anion radicals in mitochondria and resulting poly(ADP-ribose) polymerase activation. This review (a) presents findings supporting a key role for the sorbitol pathway in oxidative stress and oxidative stress-initiated downstream mechanisms of diabetic complications, and (b) summarizes experimental evidence against a detoxifying role of the sorbitol pathway, as well as the "unifying concept."