Losartan dosage, side effects

Losartan dosage, side effects:

Losartan is an angiotensin II receptor antagonist (ARB) used primarily to treat high blood pressure (hypertension) and to protect the kidneys in patients with type 2 diabetes. It works by blocking the action of angiotensin II, a substance in the body that causes blood vessels to tighten, thereby relaxing blood vessels and lowering blood pressure.

Brand Names

Losartan is sold under various brand names worldwide. Some of the most common include:

1. Cozaar (the original brand name by Merck)
2. Losartan Potassium (generic versions)
3. Lortaan (in some countries)
4. Repace (in India and other regions)
5. Losacor (in some countries)
6. Losar (in India and other regions)
7. Angizaar (in some countries)
8. Zortan (in some countries)

Uses

1. Hypertension (High Blood Pressure): Losartan is commonly prescribed to lower blood pressure, reducing the risk of strokes, heart attacks, and kidney problems.
2. Diabetic Nephropathy: It is used to slow the progression of kidney disease in patients with type 2 diabetes and high blood pressure.
3. Left Ventricular Hypertrophy: It may be used to reduce the risk of stroke in patients with high blood pressure and an enlarged heart.
4. Off-label Uses: Sometimes used for heart failure or other cardiovascular conditions, though this is less common.

Dosage

• The typical starting dose for hypertension is 50 mg once daily, which may be increased to 100 mg once daily depending on the patient’s response.
• For diabetic nephropathy, the usual dose is 50-100 mg once daily.

Side Effects

Common side effects include:

• Dizziness
• Fatigue
• Low blood pressure (hypotension)
• Hyperkalemia (high potassium levels)
• Back pain
• Cold-like symptoms

Rare but serious side effects may include:

• Kidney problems
• Allergic reactions (e.g., swelling of the face, lips, or tongue)
• Liver problems
• Muscle pain or weakness (signs of high potassium or kidney issues)

Contraindications

• Patients with a history of angioedema (swelling of the deeper layers of the skin) related to previous ARB or ACE inhibitor use.
• Pregnancy (especially in the second and third trimesters, as it can harm the fetus).
• Severe kidney or liver disease (requires careful monitoring).

Drug Interactions

• Potassium supplements or potassium-sparing diuretics: Increased risk of hyperkalemia.
• NSAIDs (e.g., ibuprofen, naproxen): May reduce the effectiveness of losartan and increase kidney risk.
• Lithium: Losartan can increase lithium levels in the blood, leading to toxicity.
• ACE inhibitors: Concurrent use is generally avoided due to increased risk of kidney problems and hyperkalemia.

Precautions

• Regular monitoring of kidney function and potassium levels is recommended.
• Patients should avoid alcohol, as it can further lower blood pressure.
• Inform your doctor if you are pregnant, planning to become pregnant, or breastfeeding.

Mechanism of Action

Losartan blocks the binding of angiotensin II to its receptors, preventing blood vessel constriction and reducing aldosterone secretion. This leads to vasodilation (widening of blood vessels), decreased blood pressure, and reduced workload on the heart.