Comparative Pharmacology
Head-to-head clinical analysis: AMLODIPINE BESYLATE AND BENAZEPRIL HYDROCHLORIDE versus TARKA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: AMLODIPINE BESYLATE AND BENAZEPRIL HYDROCHLORIDE versus TARKA.
AMLODIPINE BESYLATE AND BENAZEPRIL HYDROCHLORIDE vs TARKA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Amlodipine is a dihydropyridine calcium channel blocker that inhibits the transmembrane influx of calcium ions into vascular smooth muscle and cardiac muscle, causing peripheral vasodilation and reduction of peripheral vascular resistance. Benazepril is a prodrug that is hydrolyzed to benazeprilat, a competitive inhibitor of angiotensin-converting enzyme (ACE), preventing conversion of angiotensin I to angiotensin II, thereby reducing vasoconstriction, aldosterone secretion, and sodium and water retention.
Combination of trandolapril (angiotensin-converting enzyme inhibitor) and verapamil (calcium channel blocker). Trandolapril inhibits ACE, reducing angiotensin II production, leading to vasodilation and decreased aldosterone secretion. Verapamil blocks L-type calcium channels, causing coronary and peripheral vasodilation, and negative chronotropic/inotropic effects.
Oral, one capsule daily. Initial: 2.5 mg/10 mg for patients not on either drug; up to 10 mg/40 mg daily.
Tarka (trandolapril/verapamil) is available as fixed-dose combinations: 1 mg/180 mg, 2 mg/180 mg, 2 mg/240 mg, 4 mg/240 mg. For hypertension, initial dose is 1 mg/180 mg orally once daily; titrate based on blood pressure response, maximum dose 8 mg/480 mg per day.
None Documented
None Documented
Amlodipine terminal half-life 30-50 hours (allows once-daily dosing; steady state reached after 7-10 days). Benazeprilat effective half-life 10-11 hours (accumulation minimal).
Trandolaprilat terminal t1/2 16–24 h (prolonged in renal impairment, e.g., CrCl <30 mL/min ~36 h); verapamil t1/2 6–12 h (active metabolite norverapamil t1/2 ~12 h)
Amlodipine: 60% renal (10% unchanged, rest as metabolites), 20-25% biliary/feces. Benazepril: 11-12% renal (as unchanged benazepril and benazeprilat), 85-90% biliary (as benazeprilat conjugates).
Renal: trandolaprilat 33% (unchanged 13%), trandolapril 10%; fecal: 66% (trandolaprilat 21%, trandolapril 33%); verapamil: renal 70% (16% unchanged), fecal 16%
Category D/X
Category C
ACE Inhibitor
ACE Inhibitor + Calcium Channel Blocker