ESOMEX-40 Tablets

Indications

• Gastroesophageal reflux disease (GERD)
• Erosive esophagitis
• Peptic ulcers
• Helicobacter pylori eradication
• Zollinger-Ellison syndrome

Dosage

Adults: The usual oral dose

Mechanism of action

Esomeprazole exerts its stomach acid-suppressing effects by covalently binding to cysteine residues on the H+/K+-ATPase enzyme at the secretory surface of gastric parietal cells. This action inhibits both basal and stimulated gastric acid secretion irreversibly, requiring the synthesis of new enzyme to restore acid production. By blocking the final step of gastric acid production, esomeprazole reduces gastric acidity in a dose-dependent manner.

Pharmacodynamics

Esomeprazole is a substituted benzimidazole that inhibits gastric acid secretion without exhibiting anticholinergic or H2 receptor antagonistic properties. It is indicated for the treatment of GERD, healing of erosive esophagitis, and eradication of H. pylori to reduce duodenal ulcer recurrence. The suppression of gastric acid secretion is dose-related and effective against various stimuli that promote acid secretion.

Pharmacokinetics

Esomeprazole is rapidly absorbed after oral administration, with peak plasma concentrations typically occurring within 1-2 hours. It undergoes extensive hepatic metabolism primarily by the cytochrome P450 system, especially CYP2C19, resulting in several metabolites. The elimination half-life is approximately 1-2 hours, though its antisecretory effects last longer. It is excreted predominantly in the urine. Dose adjustments may be necessary in patients with hepatic impairment.

Contra-indications

• Hypersensitivity to esomeprazole or any of its components
• Concomitant use with rilpivirine-containing products

Adverse effects

• Abdominal pain
• Constipation
• Diarrhea
• Dizziness
• Dry mouth
• Headache
• Insomnia
• Nausea
• Skin reactions
• Vomiting
• Bone fractures
• Confusion
• Depression
• Drowsiness
• Leucopenia
• Malaise
• Myalgia
• Paraesthesia
• Peripheral edema
• Thrombocytopenia
• Vertigo
• Vision disorders
• Agranulocytosis
• Alopecia
• Gynaecomastia
• Hallucination
• Hepatic disorders
• Hyperhidrosis
• Hyponatraemia
• Nephritis
• Tubulointerstitial nephritis
• Pancytopenia
• Photosensitivity reaction
• Severe cutaneous adverse reactions (SCARs)
• Stomatitis
• Taste altered
• Hypomagnesaemia

Interactions

• Esomeprazole may increase the exposure to cannabidiol
• Esomeprazole may increase the exposure to cilostazol

Precautions

• Increased risk of fractures, particularly in the elderly and when used at high doses for over a year
• Caution in patients at risk of osteoporosis; adequate intake of calcium and vitamin D is recommended
• May increase the risk of gastrointestinal infections, including Clostridioides difficile
• Symptoms of gastric cancer should be ruled out before treatment
• Use with caution in patients with hepatic impairment

Pregnancy

Use with caution. The manufacturer advises avoiding use unless necessary since the effects on the fetus are not fully known.

Breast-feeding

Manufacturer advises avoiding use as esomeprazole is present in breast milk and may cause diarrhea in nursing infants. However, amounts are probably too small to be harmful.

Storage

Store in a cool, dry place below 25°C. Keep out of

Indications

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

Dosage

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

Adults: Apply to the skin as required for disinfection.

Mechanism of action

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

Pharmacodynamics

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

Pharmacokinetics

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

Contra-indications

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

Adverse effects

• Eye erythema
• Punctate keratitis
• Cytotoxicity
• Eye discolouration

Interactions

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

Precautions

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

Pregnancy

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

Breast-feeding

Avoid regular or excessive use.

Storage

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

Formulations

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

Indications

• Dehydration
• Fluid replacement
• Support for metabolic reactions
• Regulation of body temperature

Dosage

Children: Fluid requirements for children depend on age, weight, and activity level. It is crucial to monitor hydration status and adjust intake accordingly, referring to specific guidelines in the BNF for Children.

Adults: Dosage varies based on individual needs, activity level, and environmental conditions. General guidelines suggest approximately 2 to 3 liters per day for adults, considering factors like exercise and climate.

Mechanism of action

Water acts as a solvent in biological systems, enabling the dissolution and transport of nutrients and waste products. It also plays a vital role in metabolic reactions, including hydrolysis and dehydration synthesis, which are essential for cellular function.

Pharmacodynamics

Water maintains cellular integrity and supports physiological functions, including osmotic balance, acid-base equilibrium, and thermoregulation. Its role in enzymatic reactions and as a medium for biochemical processes is crucial for organismal health.

Pharmacokinetics

Water is absorbed efficiently in the gastrointestinal tract and distributed throughout the body via the bloodstream. It is excreted primarily through urine, sweat, and respiration. The body regulates water balance through mechanisms involving the kidneys, hormones, and thirst responses.

Pregnancy

Considered safe for use.

Breast-feeding

Considered safe for use.

Storage

Store in a cool, dry place away from sunlight.

Formulations

• Liquid
• Pure Water

Mechanism of action

Carbonate ions participate in buffering reactions that help maintain pH homeostasis in biological systems. They can react with acids to form bicarbonate and carbon dioxide, thus neutralizing excess acidity in the body. This mechanism is crucial in processes such as respiration and metabolism.

Pharmacodynamics

As a buffer, carbonate helps to stabilize pH levels in different biological environments, preventing excessive acidity or alkalinity that could impair cellular functions. It is involved in the transport of carbon dioxide in the blood and plays a role in maintaining the acid-base equilibrium necessary for physiological processes.

Pharmacokinetics

Carbonate ions are readily absorbed in the gastrointestinal tract when ingested and can be found in various body fluids. They are involved in the bicarbonate buffering system, where they are converted to bicarbonate (HCO3-) and carbon dioxide (CO2) through reactions with acids. The kidneys regulate the levels of bicarbonate and carbonate in the body, excreting or reabsorbing them as needed to maintain homeostasis.

Pregnancy

There is no specific information available regarding the use of carbonate compounds during pregnancy. Consult a healthcare provider for advice.

Breast-feeding

There is no specific information available regarding the use of carbonate compounds while breastfeeding. Consult a healthcare provider for advice.

Storage

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

Indications

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

Dosage

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

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

Mechanism of action

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

Pharmacodynamics

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

Pharmacokinetics

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

Adverse effects

• Bloating
• Flatulence
• Diarrhea
• Abdominal discomfort

Precautions

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

Pregnancy

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

Breast-feeding

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

Storage

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

Formulations

• Powder
• Capsules
• Tablets
• Granules

Indications

• Protection of active ingredients in pharmaceutical formulations
• Enhancement of drug stability
• Improvement of palatability in oral dosage forms
• Facilitation of swallowing for patients with difficulty
• Controlled release of active substances

Dosage

Children: Refer to specific product information for pediatric dosing recommendations, as this varies widely based on the formulation and active ingredient.

Adults: Refer to specific product information for dosing instructions, as this varies based on the formulation and active ingredient.

Mechanism of action

The mechanism of action for coated formulations generally involves the creation of a barrier that protects the active pharmaceutical ingredient from environmental factors like moisture and oxygen. In some cases, the coating may also control the release of the drug, allowing for extended or modified release profiles that enhance therapeutic effects. Specific coatings might interact with the gastrointestinal environment, affecting solubility and absorption rates.

Pharmacodynamics

Pharmacodynamics of coated formulations can vary widely depending on the active ingredient and the nature of the coating itself. Coatings may be designed to dissolve at specific pH levels, ensuring that the drug is released in the optimal environment for absorption. The protective nature of the coat can also affect the bioavailability of the active compound, influencing its efficacy and safety profile.

Pharmacokinetics

Pharmacokinetics of coated drugs involve considerations of absorption, distribution, metabolism, and excretion. The coating can alter the rate of drug absorption, with some coatings designed to delay release until the drug reaches the intestines. The distribution of the drug throughout the body may also be affected by the coating, as it can influence the solubility and stability of the drug in systemic circulation. Metabolism and excretion can be influenced by the characteristics of the coating material and the nature of the active ingredient.

Pregnancy

Consult healthcare provider before use. Limited data available on safety.

Breast-feeding

Consult healthcare provider before use. Limited data available on safety.

Storage

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

Indications

• Used as an excipient in solid dosage forms
• Facilitates drug disintegration and dissolution

Dosage

Children: Refer to specific product formulation guidelines as crospovidone is used as an excipient and does not have a direct dosage.

Adults: Refer to specific product formulation guidelines as crospovidone is used as an excipient and does not have a direct dosage.

Mechanism of action

Crospovidone acts by rapidly absorbing water and swelling upon contact with moisture. This action leads to the disintegration of solid dosage forms, thus increasing the surface area of the active ingredients and promoting their dissolution and subsequent absorption in the gastrointestinal tract. It does not affect the pH of the formulation, ensuring that the active ingredients remain stable.

Pharmacodynamics

Crospovidone exhibits properties that enhance the bioavailability of active ingredients in pharmaceutical formulations. Its ability to rapidly disintegrate tablets and capsules leads to quicker release and absorption of the drug into systemic circulation. As a disintegrant, it aids in the effective delivery of drugs that may otherwise be poorly soluble.

Pharmacokinetics

Crospovidone itself is not absorbed systemically when administered orally. It remains in the gastrointestinal tract, where it performs its function as a disintegrant. The pharmacokinetic profile of drugs formulated with crospovidone may be influenced by the enhanced dissolution and absorption rates provided by this excipient.

Pregnancy

Crospovidone is considered to have low toxicity and is generally regarded as safe for use during pregnancy, but specific studies are limited.

Breast-feeding

There is insufficient data on the excretion of crospovidone in human milk, but it is deemed safe for use during breastfeeding.

Storage

Store in a cool, dry place away from light and moisture, in tightly closed containers.

Formulations

• Powder
• Tablets

Mechanism of action

Dichloromethane induces mammary adenomas in rats through an indirect mechanism involving hyperprolactinaemia, resulting in benign neoplasms. It does not bind to DNA in various tissues, suggesting that its carcinogenic effects are likely mediated through metabolic pathways in the liver. In mice, DCM acts as a hepatic and pulmonary carcinogen, mediated by interaction with DNA through a glutathione (GSH) conjugate produced by the enzyme glutathione S-transferase T1-1 (GST T1-1).

Pharmacodynamics

Dichloromethane exhibits carcinogenic properties, particularly evident in animal studies where exposure leads to liver and lung tumors. The incidence of tumors varies by species, with higher susceptibility observed in mice due to differences in glutathione transferase activity. Its effects on humans are still uncertain, necessitating caution in its handling and use due to potential health risks.

Pharmacokinetics

Dichloromethane is rapidly absorbed through inhalation and dermal exposure, with peak blood concentrations occurring shortly after exposure. It undergoes extensive hepatic metabolism primarily via cytochrome P450 enzymes, leading to the formation of reactive metabolites. The elimination half-life is relatively short, with excretion occurring mainly through the lungs and urine.

Pregnancy

Dichloromethane should be avoided during pregnancy due to its potential carcinogenic effects and lack of safety data in pregnant women.

Breast-feeding

It is not known whether dichloromethane is excreted in human milk, thus it should be used with caution in breastfeeding mothers.

Storage

Store in a cool, dry place away from heat and light. Keep container tightly closed.

Dosage

Children: Refer to specific BNF for Children guidelines for the medication contained within the film formulation, as dosing will depend on the active ingredient and the patient's age and weight.

Adults: Refer to specific BNF guidelines for the medication contained within the film formulation, as dosing will vary widely based on the active ingredient.

Mechanism of action

The mechanism of action for drugs delivered via film formulations varies depending on the active pharmaceutical ingredient contained within the film. Generally, the drug is absorbed through the mucosal membranes in the mouth or gastrointestinal tract, leading to systemic circulation. This can enhance the onset of action compared to traditional solid dosage forms.

Pharmacodynamics

Pharmacodynamics will vary based on the specific drug contained in the film formulation. In general, pharmacodynamics refers to the biochemical and physiological effects of the drug on the body, including its mechanism of action, therapeutic effects, and side effects. Film formulations may provide rapid onset of action due to faster dissolution and absorption of the drug.

Pharmacokinetics

Pharmacokinetics, which includes absorption, distribution, metabolism, and excretion (ADME), will also vary by the specific active ingredient in the film formulation. In general, films may exhibit faster absorption rates due to their design, leading to quicker peak plasma concentrations. The distribution will depend on the lipophilicity of the drug, while metabolism will occur primarily in the liver, and excretion can be renal or fecal, depending on the drug's characteristics.

Pregnancy

The safety of film in pregnancy has not been well established. Use only if clearly needed.

Breast-feeding

It is unknown if film is excreted in human milk. Use with caution while breastfeeding.

Storage

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

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

• 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

• 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

Dosage

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

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

Mechanism of action

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

Pharmacodynamics

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

Pharmacokinetics

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

Pregnancy

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

Breast-feeding

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

Storage

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

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

Esomeprazole exerts its stomach acid-suppressing effects by preventing the final step in gastric acid production by covalently binding to sulfhydryl groups of cysteines found on the (H+, K+)-ATPase enzyme at the secretory surface of gastric parietal cells. This effect leads to inhibition of both basal and stimulated gastric acid secretion, irrespective of the stimulus. As the binding of esomeprazole to the (H+, K+)-ATPase enzyme is irreversible and new enzyme needs to be expressed in order to resume acid secretion, esomeprazole's duration of antisecretory effect that persists longer than 24 hours. Esomeprazole is a proton pump inhibitor that suppresses gastric acid secretion by specific inhibition of the H+/K+-ATPase in the gastric parietal cell. The S- and R-isomers of omeprazole are protonated and converted in the acidic compartment of the parietal cell forming the active inhibitor, the achiral sulphenamide. By acting specifically on the proton pump, esomeprazole blocks the final step in acid production, thus reducing gastric acidity. This effect is dose-related up to a daily dose of 20 to 40 mg and leads to inhibition of gastric acid secretion.

Pharmacodynamics

Esomeprazole is a compound that inhibits gastric acid secretion and is indicated in the treatment of gastroesophageal reflux disease (GERD), the healing of erosive esophagitis, and <i>H. pylori</i> eradication to reduce the risk of duodenal ulcer recurrence. Esomeprazole belongs to a new class of antisecretory compounds, the substituted benzimidazoles, that do not exhibit anticholinergic or H2 histamine antagonistic properties, but that suppress gastric acid secretion by specific inhibition of the H⁺/K⁺ ATPase at the secretory surface of the gastric parietal cell. By doing so, it inhibits acid secretion into the gsatric lumen. This effect is dose-related and leads to inhibition of both basal and stimulated acid secretion irrespective of the stimulus. Esomeprazole is the s-isomer of [DB00338], which is a racemate of the S- and R-enantiomer. Esomeprazole has been shown to inhibit acid secretion to a similar extent as [DB00338], without any significant differences between the two compounds _in vitro_. PPIs such as esomeprazole have also been shown to inhibit the activity of dimethylarginine dimethylaminohydrolase (DDAH), an enzyme necessary for cardiovascular health. DDAH inhibition causes a consequent accumulation of the nitric oxide synthase inhibitor asymmetric dimethylarginie (ADMA), which is thought to cause the association of PPIs with increased risk of cardiovascular events in patients with unstable coronary syndromes. Due to their good safety profile and as several PPIs are available over the counter without a prescription, their current use in North America is widespread. Long term use of PPIs such as esomeprazole has been associated with possible adverse effects, however, including increased susceptibility to bacterial infections (including gastrointestinal _C. difficile_), reduced absorption of micronutrients including iron and B12, and an increased risk of developing hypomagnesemia and hypocalcemia which may contribute to osteoporosis and bone fractures later in life.

Mechanism of action

The mechanism by which methylene chloride induces mammary adenomas in the rat is important for human hazard assessment. Female Sprague- Dawley rats receiving methylene chloride have a high blood level of prolactin. In common with the response to other agents which act via hyperprolactinaemia, the methylene chloride-induced response is of benign neoplasms only. There is no evidence for the binding of methylene chloride to the DNA of other tissues and hence it seems unlikely that it will bind to mammary tissue when the primary site of metabolism is the liver. It seems most likely, therefore, that the increased incidence of mammary adenomas is the result of an indirect mechanism operating via hyperprolactinaemia. Dichloromethane (DCM) is a hepatic and pulmonary carcinogen in mice exposed to high doses by inhalation. It has been shown previously that the incidence of liver and lung tumors does not increase in rats or hamsters exposed to the dihaloalkane under conditions similar to those that produced tumors in mice. The biological consequences of DCM exposure to humans is therefore uncertain. The carcinogenic effects of DCM in the mouse are caused by the interaction with DNA of a glutathione (GSH) conjugate that is produced by the class theta glutathione S-transferase T1-1 (GST T1-1). The species specificity is thought to be due to the greater amount of transferase activity in mouse target organs and specific nuclear localization of GST T1-1 in target cells. This paper directly compares the relative capacity and locality of DCM activation in mouse and human tissues. The results show that mouse GST T1-1 is more efficient in catalyzing the conjugation of DCM with GSH than the orthologous human enzyme. In addition, the mouse expresses higher levels of the transferase than humans in hepatic tissue. Histochemical analysis confirmed the presence of GST T1-1 in the nucleus of mouse liver cells. However, in human liver GST T1-1 was detected in bile duct epithelial cells and hepatocyte nuclei but was also present in the cytoplasm. Taking this information into account, it is unlikely that humans have a sufficiently high capacity to activate DCM for this compound to be considered to represent a carcinogenic risk. Dichloromethane (DCM) is considered a probable human carcinogen. Laboratory studies have shown an increased incidence of lung and liver cancer in mice but not in rats or hamsters. Despite the correlation between metabolism of DCM by the glutathione-S-transferase (GST) pathway and the occurrence of tumors in different species, the mechanism of tumor induction by DCM metabolites produced through the GST pathway remains unclear. In this study a V79 cell line stably transfected with the murine GST theta 1 gene (mGSTT1) was compared to the parent cell line (MZ) to determine how the construct affects DCM metabolism and the sensitivity of the cell line to DNA damage and cytotoxicity. V79 cells were treated with DCM (2.5-10mM) or formaldehyde (150-600muM) for 2hr. Also, formaldehyde produced by V79 cytosol metabolism of DCM was measured spectrophotometrically. DNA damage and DNA-protein crosslinks were measured by the standard and proteinase K-modified alkaline single cell gel electrophoresis (SCG) assays. Cytotoxicity was assessed by trypan blue stain exclusion, the Live/Dead((R)) cell viability/cytotoxicity kit for animal cells, and the neutral red assay. After DCM treatment a significant concentration-dependent increase in tail moment in the V79 MZ cells was observed compared to a significant concentration-dependent decrease in tail moment in the V79 mGSTT1 cells. Post-incubation with proteinase K significantly increased DNA migrations in DCM-treated V79 mGSTT1 cells. DCM formed significantly higher levels of formaldehyde in the cytosol of the V79 mGSTT1 cells than in the cytosol of the V79 MZ cells. Results using the cytotoxicity assays were comparable using the trypan blue and Live/Dead((R)) assays, neither showing a difference in resp