Overview
Olmesartan medoxomil is an angiotensin II receptor blocker (ARB) used for hypertension management. It works by blocking the vasoconstrictor effects of angiotensin II, leading to vasodilation and reduced blood pressure. This medication is often combined with hydrochlorothiazide for enhanced antihypertensive effects in patients not adequately controlled with monotherapy.
Mechanism of Action
Olmesartan medoxomil is a selective angiotensin II type 1 (AT1) receptor antagonist. It blocks the binding of angiotensin II to AT1 receptors in vascular smooth muscle and adrenal glands, inhibiting vasoconstriction and aldosterone secretion, resulting in vasodilation and reduced blood pressure.
Indications
- Treatment of hypertension to lower blood pressure
- Used when blood pressure is not adequately controlled with olmesartan monotherapy or hydrochlorothiazide monotherapy
- May be used alone or in combination with other antihypertensive agents
Common Doses
- 20 mg/12.5 mg
- 40 mg/12.5 mg
- 40 mg/25 mg
Dosage
Recommended starting dose is 40 mg/12.5 mg once daily for patients not adequately controlled with olmesartan monotherapy, or 20 mg/12.5 mg once daily for patients not controlled with hydrochlorothiazide monotherapy. Dose can be titrated up to 40 mg/25 mg if necessary. Not indicated for initial therapy of hypertension.
Contraindications
- Hypersensitivity to any component of olmesartan medoxomil and hydrochlorothiazide tablets
- Patients with anuria
- Co-administration with aliskiren in patients with diabetes
Side Effects
- Hypotension
- Dizziness
- Hyperkalemia
- Renal impairment
- Electrolyte imbalances (hypokalemia, hyponatremia)
- Hypersensitivity reactions
- Acute myopia
- Sprue-like enteropathy (chronic diarrhea, weight loss)
Interactions
- Increased risk of renal impairment with NSAIDs
- Potassium supplements or potassium-sparing diuretics may increase hyperkalemia risk
- Lithium toxicity may occur with concurrent use
- Alcohol may potentiate orthostatic hypotension
- Co-administration with aliskiren contraindicated in diabetes
Counseling Points
- Take once daily with or without food
- Report signs of hypotension, dizziness, or fainting
- Monitor for signs of hyperkalemia (muscle weakness, irregular heartbeat)
- Stay hydrated and avoid excessive alcohol
- Use effective contraception during treatment
- Report persistent diarrhea or unexplained weight loss
- Regular blood pressure monitoring is essential