ANTASIL TABLETS

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

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.

Indications

• Hypomagnesemia
• Magnesium deficiency
• Cardiac arrhythmias
• Eclampsia
• Asthma exacerbations
• Migraine prophylaxis

Dosage

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

Adults: Refer to clinical guidelines or specific product information for adult dosing.

Mechanism of action

Magnesium acts as a cofactor for over 300 enzymatic reactions in the body. It is essential for ATP production, the synthesis of nucleic acids, and the regulation of calcium homeostasis. By modulating calcium channels and neurotransmitter release, magnesium influences neuromuscular transmission and muscle contraction. It also plays a role in stabilizing cellular membranes and protecting against oxidative stress.

Pharmacodynamics

Magnesium's pharmacodynamics involve its effects on various physiological processes, particularly in the cardiovascular and neuromuscular systems. It helps to maintain normal muscle and nerve function and influences cardiac rhythm. Magnesium is known to inhibit excessive calcium influx into cells, thus contributing to vasodilation and lowering blood pressure. It also has a calming effect on the nervous system, which can help alleviate anxiety and promote relaxation.

Pharmacokinetics

Magnesium is absorbed primarily in the small intestine, with the efficiency of absorption being influenced by dietary factors and the presence of other minerals. The body regulates magnesium levels through renal excretion and intestinal absorption. The half-life of magnesium varies depending on the route of administration, with intravenous administration leading to quicker distribution and elimination. The majority of magnesium is stored in the bones, muscles, and soft tissues, with only a small fraction present in the extracellular fluid.

Contra-indications

• Severe renal impairment
• Myasthenia gravis
• Hypocalcemia
• Hypophosphatemia

Adverse effects

• Diarrhea
• Nausea
• Vomiting
• Abdominal cramping
• Hypotension
• Bradypnea
• Muscle weakness

Interactions

• Antibiotics (e.g., tetracyclines, fluoroquinolones) - may bind and reduce their absorption
• Calcium supplements - may compete for absorption
• Diuretics (especially loop diuretics) - can increase the risk of magnesium deficiency
• ACE inhibitors - may enhance the hypotensive effect
• Neuromuscular blocking agents - may potentiate their effects

Precautions

• Use with caution in patients with renal impairment
• Monitor electrolytes in patients with gastrointestinal losses
• Avoid in patients with heart block
• Caution in elderly patients due to potential for electrolyte imbalance

Pregnancy

Magnesium is generally considered safe during pregnancy and is often recommended for certain conditions, such as preeclampsia.

Breast-feeding

Magnesium is excreted in breast milk but is generally considered safe for use during breastfeeding.

Storage

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

Formulations

• Oral tablets
• Oral solution
• Intravenous injection
• Intramuscular injection

Indications

• Gastric hyperacidity
• Heartburn
• Indigestion
• Gastritis
• Peptic ulcers

Dosage

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

Adults: Refer to specific product guidelines for dosing, as it may vary based on formulation.

Mechanism of action

Trisilicate works by reacting with hydrochloric acid in the stomach to form neutral compounds, which reduces acidity. This action helps to alleviate symptoms of acid-related disorders by increasing the pH level in the stomach.

Pharmacodynamics

Trisilicate exhibits its therapeutic effects primarily through acid neutralization. By decreasing the acidity of gastric contents, it provides symptomatic relief from conditions such as gastritis, gastroesophageal reflux disease (GERD), and peptic ulcers. The onset of action is typically rapid, with effects lasting for a few hours.

Pharmacokinetics

The pharmacokinetics of trisilicate involve minimal systemic absorption since the drug primarily acts locally within the gastrointestinal tract. The compound is excreted unchanged in the feces. Its onset of action is usually within minutes after administration, with a duration of effect that can last several hours, depending on gastric emptying and the formulation used.

Pregnancy

Trisilicate is not recommended for use during pregnancy unless the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Trisilicate may be used during breastfeeding, but it is advisable to consult a healthcare professional before use.

Storage

Store in a cool, dry place, protected from light.

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