Raksharab

Indications

• Dyspepsia
• Peptic ulcer disease
• Gastroesophageal reflux disease (GERD)
• Heartburn
• Diarrhea
• Mucosal irritations

Dosage

Children: Refer to the BNF for Children for appropriate dosing guidelines.

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

Mechanism of action

Aluminum acts as an astringent, causing local shrinkage or constriction of body tissues through osmotic flow of fluids away from the area of application. This mechanism assists in reducing mucous secretions and managing conditions such as peptic ulcers and diarrhea. Additionally, it can help in drying and hardening of tissues when applied topically.

Pharmacodynamics

Aluminum-based antacids work by neutralizing gastric acid, leading to an increase in gastric pH. This action helps to alleviate symptoms associated with excess gastric acid, such as heartburn and discomfort. The astringent properties of aluminum also contribute to its therapeutic effects in managing mucosal irritations and secretions.

Pharmacokinetics

Aluminum is absorbed minimally when taken orally, with a bioavailability of about 0.1 to 0.5%. The majority of aluminum is excreted renally, and its half-life can be prolonged in individuals with renal impairment. Long-term use may lead to accumulation and potential toxicity, particularly impacting bone and neurological health.

Interactions

• aluminiumhydroxide+deferasirox: Severe (decreases exposure)
• aluminiumhydroxide+enteralfeeds: Unknown (increases risk of blocked enteral or nasogastric tubes)
• aluminiumhydroxide+roxadustat: Unknown (decreases exposure)

Pregnancy

Aluminum compounds are generally considered safe in pregnancy when used as directed. However, excessive exposure should be avoided.

Breast-feeding

Aluminum is excreted in breast milk; caution is advised when administered to nursing mothers.

Storage

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

Formulations

• aluminium hydroxide suspension
• aluminium hydroxide tablets

Indications

• Bloating
• Flatulence
• Dyspepsia
• Preparation for diagnostic procedures (e.g., ultrasound, endoscopy)
• Post-operative gas relief

Dosage

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

Adults: Refer to specific product guidelines for dosing information, as doses may vary based on formulation and indication.

Mechanism of action

Antifoam agents, such as simethicone, act primarily by altering the surface tension of gas bubbles in the gastrointestinal tract, allowing the bubbles to coalesce into larger bubbles that can be more easily expelled. This mechanism reduces bloating and discomfort associated with excess gas.

Pharmacodynamics

The pharmacodynamics of antifoam agents involve the reduction of surface tension in foamy liquids, which leads to the disintegration of foam. This action can alleviate symptoms of gas and bloating, making it particularly useful in both pre- and post-operative settings, as well as in the treatment of certain digestive disorders. Its effects are generally localized to the gastrointestinal tract.

Pharmacokinetics

Antifoam agents are not absorbed systemically; they act locally in the gastrointestinal tract. They are excreted unchanged in feces, and their onset of action is typically rapid, providing relief from symptoms within minutes to hours after administration. Due to their non-systemic nature, they are considered safe for use in various populations.

Adverse effects

• Nausea
• Vomiting
• Diarrhea
• Abdominal discomfort

Precautions

• Use with caution in patients with known hypersensitivity to antifoam agents.
• Assess for underlying gastrointestinal conditions before use.

Pregnancy

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

Breast-feeding

Considered generally safe, but consult a healthcare provider.

Storage

Store at room temperature, away from moisture and direct sunlight.

Formulations

• Oral suspension
• Chewable tablets
• Emulsion

Indications

• Vaccination against infectious diseases
• Allergy testing and immunotherapy
• Monoclonal antibody production
• Transplantation to prevent organ rejection

Dosage

Children: Dosing of antigens in children also depends on the specific antigen and the clinical indication. For pediatric vaccinations, refer to the BNF for Children.

Adults: Dosing of antigens is highly variable and depends on the specific antigen and the clinical indication. For vaccine administration, refer to national immunization guidelines.

Mechanism of action

Antigens work by binding to specific receptors on the surface of immune cells, such as B cells and T cells. This binding triggers a cascade of immune responses, including the proliferation of specific immune cell populations and the production of antibodies that target the antigen. This process is crucial for the development of adaptive immunity, allowing the body to remember and respond more effectively to future encounters with the same antigen.

Pharmacodynamics

The pharmacodynamics of antigens involve the interaction with the immune system to elicit a response. The magnitude and quality of this response can vary based on several factors, including the nature of the antigen, the route of exposure, and the host's immune status. Antigens can be classified as T-cell dependent or T-cell independent, influencing the type of immune response generated.

Pharmacokinetics

Antigens are processed by antigen-presenting cells (APCs) that present peptide fragments to T cells. The pharmacokinetics of antigens can vary widely depending on their form (e.g., live attenuated, inactivated, or subunit vaccines). Generally, once introduced into the body, antigens are taken up by APCs, which then migrate to lymph nodes to activate T and B cells. The duration of immune response can be influenced by the type of antigen and the presence of adjuvants.

Pregnancy

Safety during pregnancy depends on the specific type of antigen. Consult relevant guidelines for specific antigens.

Breast-feeding

Safety during breastfeeding varies by antigen type. Consult relevant guidelines for specific antigens.

Storage

Store at controlled room temperature, away from light and moisture. Specific storage conditions may vary based on the type of antigen.

Indications

• pH stabilization in laboratory experiments
• buffering during physiological studies
• preparation of samples for biochemical assays
• maintenance of pH in parenteral fluids

Dosage

Children: Refer to specific buffer formulations for detailed dosing guidance.

Adults: Refer to specific buffer formulations for detailed dosing guidance.

Mechanism of action

Buffers work by neutralizing added acids or bases through chemical reactions. For example, a buffer composed of acetic acid and sodium acetate can absorb excess hydrogen ions (from added acids) or donate hydrogen ions (to neutralize added bases), thus stabilizing the pH of the solution. This equilibrium is governed by the Henderson-Hasselbalch equation, which relates pH to the concentrations of the acidic and basic components of the buffer.

Pharmacodynamics

The pharmacodynamics of buffers involves their capacity to maintain pH levels within a target range, which is essential for various physiological processes. For instance, physiological buffers such as bicarbonate and phosphate play critical roles in maintaining the acid-base balance in the body, ensuring proper cellular function, enzyme activity, and metabolic processes.

Pharmacokinetics

The pharmacokinetics of buffer components depends on their specific chemical nature. Weak acids and bases used in buffers are typically absorbed and metabolized according to their molecular characteristics. For instance, bicarbonate can be reabsorbed in the kidneys and plays a significant role in systemic pH regulation. However, since buffer solutions are not typically absorbed in the same way as pharmaceutical drugs, their pharmacokinetic profiles are less relevant in a conventional sense.

Pregnancy

Buffering agents are generally considered safe during pregnancy; however, specific formulations should be evaluated for safety and efficacy.

Breast-feeding

Most buffering agents are considered safe during breastfeeding, but it is advisable to consult healthcare providers regarding specific formulations.

Storage

Store in a cool, dry place, away from direct sunlight and moisture. Follow specific storage instructions on the product label.

Indications

• Preparation of injectable medications
• Reconstitution of powdered medications
• Dilution of concentrated solutions for safe administration
• Facilitation of oral dosing for patients with difficulty swallowing

Dosage

Children: Refer to specific drug guidelines for appropriate dilution and administration.

Adults: Refer to specific drug guidelines for appropriate dilution and administration.

Mechanism of action

Diluents do not have a specific pharmacological mechanism of action as they are generally inert substances. Their primary role is to provide a suitable medium for the solubilization of active ingredients, thereby facilitating their administration and absorption. The action of the drug being diluted will depend on its own pharmacodynamics once it is reconstituted or diluted in the appropriate diluent.

Pharmacodynamics

Pharmacodynamics of diluents is not applicable as they do not exert therapeutic effects on their own. Instead, they serve as a medium that may affect the release and absorption of the active drug once administered. The pharmacodynamic properties of the final dosage form will depend on the active drug and its interaction with the body.

Pharmacokinetics

Like pharmacodynamics, the pharmacokinetics of diluents are not specifically defined. Diluents are typically absorbed or metabolized based on their chemical nature. For example, sterile water for injection is rapidly absorbed and distributed in the body, while saline may influence electrolyte balance. The pharmacokinetics of the active drug will primarily determine the overall therapeutic outcomes post-dilution.

Pregnancy

Generally considered safe when used appropriately; however, specific diluents may have individual safety profiles.

Breast-feeding

Generally considered safe when used appropriately; specific recommendations may vary based on the diluent used.

Storage

Store at room temperature, away from light and moisture. Follow specific storage instructions for each formulation.

Formulations

• Normal saline
• Dextrose solutions
• Ringer's lactate
• Sterile water for injection

Dosage

Children: Refer to specific guidelines for pediatric dosing; consult the BNF for Children for accurate dosage information.

Adults: Refer to specific guidelines for use; dosage may vary based on the context of use.

Mechanism of action

Hydroxide ions act primarily as bases, neutralizing acids to form water and salts. They participate in various biochemical pathways, including selenium metabolism and the degradation of reactive oxygen species. Hydroxide can influence enzyme activity and stability by altering the pH of the environment, thereby affecting metabolic reactions.

Pharmacodynamics

Hydroxide ions can impact biological processes by changing the local pH, which influences enzyme activity, ion transport, and the solubility of other compounds. Their ability to neutralize acids can help regulate physiological pH, contributing to homeostasis in living organisms.

Pharmacokinetics

As an inorganic ion, hydroxide does not undergo traditional pharmacokinetic processes like absorption, distribution, metabolism, or excretion. Instead, it is rapidly equilibrated in biological fluids and participates in acid-base reactions, having immediate effects on the local environment.

Pregnancy

There is limited information regarding the use of hydroxide during pregnancy. Consult a healthcare professional for advice.

Breast-feeding

Limited data is available on the excretion of hydroxide in breast milk. Consult a healthcare professional before use.

Storage

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

Dosage

Children: Refer to specific drug monographs for dosing information, as potency varies widely among different medications.

Adults: Refer to specific drug monographs for dosing information, as potency varies widely among different medications.

Mechanism of action

Potency does not have a unique mechanism of action; rather, it is a characteristic of a drug's interaction with its target receptors. Generally, the mechanism of action involves binding to specific receptors or enzymes, influencing physiological processes to achieve the desired therapeutic effect.

Pharmacodynamics

Pharmacodynamics describes how a drug affects the body, including the relationship between drug concentration and effect. Potency is assessed through dose-response curves, where the effect of a drug is plotted against its concentration. A highly potent drug will elicit a significant response at lower concentrations, indicating a strong affinity for its target receptors.

Pharmacokinetics

Pharmacokinetics involves the absorption, distribution, metabolism, and excretion of a drug. The potency of a drug can influence its pharmacokinetic properties, as highly potent drugs may require careful consideration of dosing regimens to avoid toxicity. Factors such as bioavailability, half-life, and clearance rates are essential in understanding how potency affects the overall duration and intensity of drug action.

Pregnancy

The effects of potency on pregnancy are not well-documented. It is important to consult healthcare providers regarding any concerns about potency and its effects during pregnancy.

Breast-feeding

Information regarding the effects of potency during breastfeeding is limited. Consultation with healthcare providers is recommended for breastfeeding mothers.

Storage

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

Indications

• Rabies prevention in individuals at high risk of exposure
• Post-exposure prophylaxis following potential rabies exposure
• Vaccination for travelers to endemic regions

Dosage

Children: Refer to the BNF for Children for specific dosing recommendations for pediatric patients.

Adults: Refer to the BNF for specific dosing guidelines, as it varies based on exposure risk and vaccination history.

Mechanism of action

The rabies vaccine works by stimulating the immune system to produce antibodies against the rabies virus. This is achieved through the introduction of inactivated or attenuated virus particles, which mimic the infection without causing the disease. The immune response generated helps to prevent the virus from causing illness upon subsequent exposure.

Pharmacodynamics

The rabies vaccine induces an adaptive immune response, leading to the production of neutralizing antibodies specific to the rabies virus. This immune memory protects against future infections. The vaccine is typically administered in a series of doses to ensure adequate immune response and long-term protection.

Pharmacokinetics

The pharmacokinetics of the rabies vaccine involve absorption at the injection site, followed by systemic distribution of the antigens. The onset of immunity generally occurs within two weeks after the initial vaccination, with peak antibody levels typically reached within one to two months. The duration of immunity can vary, necessitating booster doses in certain populations.

Interactions

• chloroquine+rabiesvaccine: Severe (decreases efficacy)

Pregnancy

Rabies vaccination is generally considered safe during pregnancy. However, the risks and benefits should be carefully evaluated.

Breast-feeding

Rabies vaccine is not known to cause any adverse effects in breastfeeding. However, consult with a healthcare provider for individual assessments.

Storage

Store the rabies vaccine in a refrigerator at 2-8 degrees Celsius. Do not freeze.

Indications

• Preservative in vaccines
• Antibacterial agent
• Antifungal agent

Dosage

Children: Refer to the BNF for Children for specific dosage guidelines, especially in

Adults: Refer to specific product guidelines or the BNF for detailed dosage information, as thimerosal is primarily used as a preservative in vaccines rather than in therapeutic doses.

Mechanism of action

Thimerosal inhibits sulfhydryl-containing active sites of various enzymes and binds to sulfhydryl compounds, including glutathione and cysteine. It activates the InsP3 calcium channel on the endoplasmic reticulum, leading to the release of intracellular calcium and subsequent cellular functions dependent on calcium signaling. Ethylmercury, the metabolite of thimerosal, is lipophilic and can cross the blood-brain barrier, contributing to its biological effects.

Pharmacodynamics

Thimerosal exhibits antibacterial and antifungal properties, functioning as a preservative in vaccines. Its pharmacological effects are mediated through interactions with cellular thiols and modulation of calcium signaling pathways. The toxic effects of high doses of thimerosal, such as oxidative stress and apoptosis, have been observed in vitro, although the effects of low-dose exposure remain less understood.

Pharmacokinetics

Thimerosal is rapidly metabolized to ethylmercury, which is eliminated from the body more quickly than methylmercury. Ethylmercury has a shorter half-life, leading to limited accumulation and toxic potential when used in vaccine formulations. The octanol/water partition coefficients indicate that both organomercury compounds, including ethylmercury, can primarily exist within cells, allowing them to cross cellular membranes effectively.

Adverse effects

• Hypersensitivity reactions
• Local reactions at injection site
• Neurotoxic effects at high doses
• Possible kidney pathology with toxic quantities

Precautions

• Use with caution in individuals with known hypersensitivity to thimerosal or other mercury compounds
• Monitoring for adverse effects in patients receiving multiple vaccines containing thimerosal

Pregnancy

Thimerosal should be used in pregnant women only if clearly needed, as the effects on fetal development are not fully established.

Breast-feeding

Thimerosal is considered compatible with breastfeeding, but caution is advised due to potential mercury exposure.

Storage

Store in a cool, dry place away from light. Protect from freezing. Ensure proper disposal of any unused or expired vaccine containing thimerosal.

Formulations

• Thimerosal-containing vaccines (various formulations)

Indications

• Cyanide poisoning
• Detoxification in cases of heavy metal poisoning
• Potential adjunct in certain metabolic disorders

Dosage

Children: Refer to the BNF for Children for specific dosing guidelines in paediatric patients.

Adults: For cyanide poisoning, the typical adult dose is 12.5 g (50 mL of a 25% solution) administered intravenously over 30 minutes. Repeat doses may be given if necessary, based on clinical judgment and response.

Mechanism of action

Thiosulphate acts as a sulfur donor, facilitating the conversion of cyanide to thiocyanate through the action of the enzyme rhodanese. This detoxification process allows for the safe excretion of cyanide from the body, thereby mitigating its toxic effects. Additionally, thiosulphate is involved in various metabolic pathways, including cysteine biosynthesis and sulfur metabolism, indicating its broader role in biological systems.

Pharmacodynamics

Thiosulphate exhibits its pharmacological effects primarily through its ability to bind free cyanide ions, forming thiocyanate, which is significantly less toxic. Its action enhances the body's natural detoxification mechanisms and supports the metabolism of sulfur-containing compounds. The drug demonstrates a relatively rapid onset of action, crucial in acute poisoning scenarios.

Pharmacokinetics

Thiosulphate is typically administered intravenously in acute settings. It is rapidly distributed in the body, with a significant volume of distribution. The compound is well tolerated and is excreted primarily through the kidneys. Its elimination half-life can vary depending on the dose and individual patient factors, but it is generally eliminated efficiently due to its water-soluble nature.

Pregnancy

There is limited data on the use of thiosulphate during pregnancy. It should only be used if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Thiosulphate is excreted in breast milk, and caution should be exercised when administered to a nursing mother.

Storage

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

Mechanism of action

Aluminum Acetate is an astringent. An astrignent is a chemical that tends to shrink or constrict body tissues, usually locally after topical medicinal application. The shrinkage or constriction is through osmotic flow of water (or other fluids) away from the area where the astringent was applied. Astringent medicines cause shrinkage of mucous membranes or exposed tissues and are often used internally to check discharge of blood serum or mucous secretions. This can happen with a sore throat, hemorrhages, diarrhea, or with peptic ulcers. Externally applied astringents, which cause mild coagulation of skin proteins, dry, harden, and protect the skin. Acne sufferers are often advised to use astringents if they have oily skin. Astringents also help heal stretch marks and other scars. Mild astringent solutions are used in the relief of such minor skin irritations as those resulting from superficial cuts, allergies, insect bites, or fungal infections such as athlete's foot. Excessive dietary aluminum has been proposed to be a factor contributing to several neurological disorders in humans. Six 8-week-old female Swiss Webster mice were fed for 10 wk purified diets containing 100 (control), 500 or 1000 ug aluminum/g diet. Brain and liver lipid peroxidation was determined by evaluating the production of 2-thiobarbituric acid reactive substances in brain and liver homogenates in the presence or absence of 50 uM ferrous iron. 2-Thiobarbituric acid reactive substances production in the absence of iron in brain homogenates from mice fed the 1000 ug/g diet was higher (30%) than that in the 100 ug/g control group (3.1 vs 2.4 nmol 2-thiobarbituric acid reactive substances/mg protein). The addition of ferrous iron increased 2-thiobarbituric acid reactive substances production in brain homogenates from all 3 dietary groups. The iron induced 2-thiobarbituric acid reactive substances production was 26% higher in the 1000 ug/g brain homogenates than in the 100 ug/g group (4.9 vs 3.9 nmol 2-thiobarbituric acid reactive substances/mg protein). Brain 2-thiobarbituric acid reactive substances production in the presence and absence of iron was similar between the 100 and 500 ug/g aluminum groups. 2-Thiobarbituric acid reactive substances production in liver homogenates measured either with or without iron was similar for the 3 groups. These results show that, in mice, dietary aluminum intoxication leads to increased brain 2-thiobarbituric acid reactive substance production, suggesting that enhanced lipid peroxidation may be one possible mechanism underlying the neurological damage associated with increased tissue aluminum. Evidence is presented indicating that dementias are associated with a relative insufficiency of magnesium in the brain. Such insufficiency may be attributable to low intake or retention of magnesium; high intake of a neurotoxic metal, such as aluminum, which inhibits activity of magnesium requiring enzymes; or impaired transport of magnesium and/or enhanced transport of the neurotoxic metal into brain tissue. It is proposed that Alzheimer's disease involves a defective transport process, characterized by both an abnormally high incorporation of aluminum and an abnormally low incorporation that an altered serum protein contributes to the progression of Alzheimer's disease by having a greater affinity for aluminum than for magnesium, in contrast to the normal protein, which binds magnesium better than aluminum. The altered protein crosses the blood-brain barrier more efficiently than the normal protein and competes with the normal protein in binding to brain neurons. Binding of the altered protein to the target neurons would both facilitate aluminum uptake and impede magnesium uptake. Evidence suggests that albumin is the serum protein that is altered. Aluminum is established as a neurotoxin, although the basis for its toxicity is unknown. It recently has been shown to alter the function of the blood-brain barrier, which regulates ex

Mechanism of action

Although its mechanism of action is not fully understood, thimerosal inhibits sulfhydryl-containing active site of various enzymes and binds to sulfhydryl compounds, including glutathione, cysteine, and sulfhydryl groups of proteins. In addition, thimerosal activates the InsP3 calcium channel on the endoplasmic reticular membrane, thereby triggering the release of intracellular calcium resulting in a calcium-induced calcium-influx of extracellular calcium. Therefore, thimerosal may induce or inhibit various cellular functions that are dependent on the signaling of calcium. Ethylmercury is metabolized to inorganic mercury more rapidly than methylmercury. This difference in metabolism may account for kidney pathology that can result from toxic quantities. Also, whereas the increase in oxidative stress and induction of apoptosis observed in vitro with large doses (405 μg/L to 101 mg/L) of thimerosal may explain its damaging neurological effects. The effects of low-dose ethylmercury are not completely understood to date. It is known, however, that the shorter half-life of ethylmercury (the metabolite of thimerosal) allows for very limited opportunities of ethylmercury derived from thimerosal in vaccines. Ethylmercury is a lipophilic cation that is capable of crossing the blood-brain barrier. The octanol/water partition coefficients of methyl and ethylmercury are 1.4 to 1.8, at intracellular pH and [Cl−], therefore, both organomercury compounds will primarily exist as intracellular lipophilic cations. It has been demonstrated that lipophilic cations accumulate inside mitochondria, in a Nernstian fashion, driven by the steady state membrane potential. As the typical mitochondrial membrane potential of astrocytes and neurons is between 140–170 mV, one would expect the concentration of these organomercury compounds within mitochondria to be approximately 1000 times greater than the cytosolic concentration.

Pharmacodynamics

Thimerosal is an organomercurial compound and derivative of thiosalicyclic acid with antibacterial and antifungal properties. Thimerosal, which consists of approximately 50% mercury by weight, has been one of the most widely used preservatives in vaccines. It is metabolized/degraded to ethylmercury and thiosalicylate. Ethylmercury is an organomercurial that must be carefully distinguished from methylmercury, a closely related substance that has been the focus of many studies. Methylmercury is the type of mercury found in various species of fish. Experimental data demonstrates that the toxicokinetics of thimerosal (ethylmercury) is vastly different from that of methyl-mercury. Thus, methyl-mercury is not a suitable reference for assessing the risk from exposure to thimerosal-derived mercury. Prior to the recent initiative to reduce or eliminate thimerosal from childhood vaccines, the maximum cumulative exposure to mercury via routine childhood vaccinations during the first 6 months of life was 187.5 micrograms. In the most recently formulated vaccines, the maximum cumulative exposure during the first 6 months of life should now be less than 3 micrograms of mercury. Currently, thimerosal may still be used in the early stages of manufacturing of certain childhood vaccines, however, only a trace remains after a chemical purification process. Note that the dose above is indicated for children 1-6 months of age is applicable only in the United States, and other countries may have varying indications.