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Angiotensin II Receptor Blockers (ARBs)
1. Enumeration of ARBs
- Losartan
- Valsartan
- Irbesartan
- Candesartan
- Telmisartan
- Olmesartan
2. Mechanism of Action
ARBs selectively block the binding of angiotensin II to AT1 receptors, preventing vasoconstriction and aldosterone secretion. This results in vasodilation, reduced blood pressure, and decreased sodium and water retention.
3. Therapeutic Doses
- Losartan: 50 mg once daily (up to 100 mg)
- Valsartan: 80 mg to 160 mg once daily (up to 320 mg)
- Irbesartan: 150 mg once daily (up to 300 mg)
- Candesartan: 8 mg once daily (up to 32 mg)
- Telmisartan: 40 mg once daily (up to 80 mg)
- Olmesartan: 20 mg once daily (up to 40 mg)
4. Indications
- Hypertension
- Heart failure
- Chronic kidney disease
- Post-myocardial infarction
- Diabetic nephropathy
5. Adverse Effects
- Hypotension
- Hyperkalemia
- Renal impairment
- Dizziness
- Cough (less common)
- Angioedema (rare)
- Fatigue
6. Contraindications
- Hypersensitivity to ARBs
- Pregnancy (especially second and third trimesters)
- Severe renal impairment
- Concomitant use with aliskiren in certain patients
- History of angioedema related to previous ARB or ACE inhibitor therapy
Conclusion
ARBs are essential antihypertensive agents with a favorable side effect profile and important cardiovascular and renal protective effects.
