Comparative Pharmacology
Head-to-head clinical analysis: AVALIDE versus OLMESARTAN MEDOXOMIL AND HYDROCHLOROTHIAZIDE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: AVALIDE versus OLMESARTAN MEDOXOMIL AND HYDROCHLOROTHIAZIDE.
AVALIDE vs OLMESARTAN MEDOXOMIL AND HYDROCHLOROTHIAZIDE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Avalide is a combination of an angiotensin II receptor blocker (irbesartan) and a thiazide diuretic (hydrochlorothiazide). Irbesartan blocks the vasoconstrictor and aldosterone-secreting effects of angiotensin II by selectively antagonizing the AT1 receptor. Hydrochlorothiazide increases sodium and water excretion by inhibiting the Na+/Cl- symporter in the distal convoluted tubule.
Olmesartan medoxomil is an angiotensin II receptor blocker (ARB) that selectively inhibits angiotensin II binding to AT1 receptors, reducing vasoconstriction and aldosterone secretion. Hydrochlorothiazide is a thiazide diuretic that inhibits sodium and chloride reabsorption in the distal convoluted tubule, increasing diuresis and lowering blood pressure.
AVALIDE (irbesartan/hydrochlorothiazide) is available as tablets containing 150/12.5 mg, 300/12.5 mg, or 300/25 mg. The typical starting dose is 150/12.5 mg once daily, titrated to 300/12.5 mg once daily as needed. Maximum dose is 300/25 mg once daily.
Oral, one tablet once daily. Starting dose: Olmesartan medoxomil 20 mg / hydrochlorothiazide 12.5 mg. Titrate up to maximum 40 mg / 25 mg daily as needed.
None Documented
None Documented
Irbesartan: 11-15 h (terminal), HCTZ: 6-15 h (terminal). Clinical context: Steady state reached in 3-5 days; allows once-daily dosing.
Olmesartan: terminal half-life ~10–15 hours; no accumulation. Hydrochlorothiazide: terminal half-life ~6–15 hours; prolonged in renal impairment.
Renal: HCTZ ~70% unchanged; Irbesartan ~20% unchanged, remainder as metabolites via biliary (60%) and renal (20%). Combined: Renal ~50%, biliary/fecal ~50%.
Olmesartan: ~60% renal, ~35% fecal. Hydrochlorothiazide: ~70% renal (unchanged), ~30% biliary/fecal.
Category C
Category D/X
ARB and Thiazide Diuretic Combination
ARB