ANGITAN TABLETS 50MG

Indications

• Hypertension
• Heart failure
• Diabetic nephropathy
• Left ventricular hypertrophy
• Chronic kidney disease

Dosage

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

Adults: Refer to established guidelines for specific dosing based on individual patient needs and clinical conditions.

Mechanism of action

Losartan selectively blocks the binding of angiotensin II to the AT1 receptor, which is responsible for the vasoconstrictor effects of angiotensin II. This blockade results in vasodilation, reduced secretion of aldosterone, decreased reabsorption of sodium, and an overall reduction in blood pressure. Additionally, losartan has been shown to increase plasma renin activity and angiotensin II levels, which may contribute to its therapeutic effects.

Pharmacodynamics

Losartan reduces blood pressure through its antihypertensive effects, which include vasodilation and decreased peripheral vascular resistance. It has a long duration of action, allowing for once-daily dosing in most cases. The pharmacodynamic effects also include favorable renal outcomes in patients with diabetic nephropathy.

Pharmacokinetics

Losartan is rapidly absorbed following oral administration, with peak plasma concentrations occurring within 1 to 2 hours. It undergoes extensive first-pass metabolism in the liver to form an active metabolite, E3174, which has a longer half-life and contributes to the drug's pharmacological effects. Losartan and its metabolite are both primarily eliminated via the kidneys and feces. The elimination half-life of losartan is approximately 2 hours, while that of E3174 is about 6 to 9 hours.

Contra-indications

• Hypersensitivity to losartan or any of its components
• Pregnancy
• Severe hepatic impairment
• Bilateral renal artery stenosis

Adverse effects

• Dizziness
• Fatigue
• Headache
• Hypotension
• Hyperkalemia
• Renal impairment

Interactions

• Potassium-sparing diuretics may increase the risk of hyperkalemia
• Non-steroidal anti-inflammatory drugs (NSAIDs) may reduce the antihypertensive effect
• Lithium concentrations may increase when used with losartan

Precautions

• Monitor renal function regularly when initiating therapy
• Caution in patients with dehydration or volume depletion
• Assess electrolyte levels periodically, particularly potassium

Pregnancy

Losartan is contraindicated during pregnancy due to the risk of fetal harm.

Breast-feeding

Limited data, use with caution after assessing the risk-benefit ratio.

Storage

Store at room temperature, away from moisture and heat.

Formulations

• Tablets: 25 mg, 50 mg, 100 mg

Indications

• Hypokalemia (low serum potassium levels)
• Hypertension (as part of dietary management)
• Heart disease (to prevent arrhythmias)
• Muscle cramps (related to low potassium levels)

Dosage

Children: Refer to guidelines for specific dosing recommendations based on age and clinical condition.

Adults: Dosage varies based on clinical condition and serum potassium levels. Refer to established guidelines for specific dosing recommendations.

Mechanism of action

Potassium ions are crucial for the generation and conduction of action potentials in neurons and muscle cells. They help to maintain the membrane potential and are involved in the repolarization phase of the action potential. Additionally, potassium plays a role in enzymatic reactions and the synthesis of proteins.

Pharmacodynamics

Potassium participates in numerous physiological processes, including muscle contraction, nerve transmission, and cardiac function. Adequate levels of potassium help to prevent arrhythmias and support overall cardiovascular health. It also influences the function of the kidneys, adrenal glands, and other organs involved in electrolyte and fluid balance.

Pharmacokinetics

Potassium is absorbed in the gastrointestinal tract, with the majority of absorption occurring in the small intestine. The distribution of potassium within the body is primarily intracellular, with most of it located within cells. The kidneys regulate potassium levels through filtration and reabsorption, with excess potassium being excreted in urine. Factors such as diet, renal function, and hormonal regulation can impact potassium homeostasis.

Contra-indications

• Hyperkalemia
• Severe renal impairment
• Untreated Addison's disease
• Acute dehydration

Adverse effects

• Hyperkalemia
• Cardiac arrhythmias
• Muscle weakness
• Nausea
• Vomiting
• Diarrhea
• Abdominal cramping

Interactions

• Angiotensin-converting enzyme (ACE) inhibitors may increase potassium levels
• Potassium-sparing diuretics can lead to hyperkalemia
• Non-steroidal anti-inflammatory drugs (NSAIDs) may reduce renal excretion of potassium
• Digoxin toxicity may occur with elevated potassium levels

Precautions

• Monitor serum potassium levels regularly
• Use with caution in patients with renal dysfunction
• Consider dietary potassium intake in patients on potassium supplements
• Be cautious in patients with cardiac disease

Pregnancy

Potassium is essential during pregnancy, but supplementation should only be done under medical supervision to avoid hyperkalemia.

Breast-feeding

Potassium is present in breast milk and is important for nursing infants, but additional supplementation should be approached with caution.

Storage

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

Formulations

• Oral tablets
• Oral liquid
• Intravenous solution
• Effervescent tablets