Comparative Pharmacology
Head-to-head clinical analysis: AVALIDE versus VALSARTAN HYDROCHLOROTHIAZIDE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: AVALIDE versus VALSARTAN HYDROCHLOROTHIAZIDE.
AVALIDE vs VALSARTAN; 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.
Valsartan is an angiotensin II receptor blocker (ARB) that selectively blocks the binding of angiotensin II to the AT1 receptor, leading to vasodilation and reduced aldosterone secretion. Hydrochlorothiazide is a thiazide diuretic that inhibits the sodium-chloride symporter in the distal convoluted tubule, increasing excretion of sodium and water.
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.
80-320 mg valsartan / 12.5-25 mg hydrochlorothiazide once daily orally, titrated based on blood pressure response.
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.
Valsartan: terminal half-life is approximately 6 hours. Hydrochlorothiazide: terminal half-life ranges from 5.6 to 14.8 hours, with an average of about 8 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%.
Valsartan: primarily excreted unchanged in feces (70%) via biliary elimination, with renal excretion accounting for about 30% (mostly unchanged). Hydrochlorothiazide: eliminated by renal excretion, with approximately 95% of the absorbed dose excreted unchanged in urine via tubular secretion.
Category C
Category D/X
ARB and Thiazide Diuretic Combination
ARB