Comparative Pharmacology
Head-to-head clinical analysis: CARDIZEM CD versus TARKA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CARDIZEM CD versus TARKA.
CARDIZEM CD vs TARKA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Diltiazem is a calcium channel blocker that inhibits calcium ion influx across cardiac and vascular smooth muscle cell membranes, resulting in dilation of coronary arteries and peripheral arterioles, and decreased myocardial contractility and conduction velocity.
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.
Hypertension: 180-360 mg once daily orally. Angina: 120-360 mg once daily orally. Maximum dose: 480 mg/day.
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
Terminal elimination half-life: 6-8 hours (single dose), prolonged to 10-15 hours with multiple dosing or in elderly/hepatic impairment. Clinical context: Therapeutic steady-state achieved in 2-4 days.
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)
Renal: ~2-4% (unchanged), Hepatic metabolism to multiple metabolites; ~65% renal (metabolites), ~35% fecal/biliary. Total clearance: 5-7 mL/kg/min.
Renal: trandolaprilat 33% (unchanged 13%), trandolapril 10%; fecal: 66% (trandolaprilat 21%, trandolapril 33%); verapamil: renal 70% (16% unchanged), fecal 16%
Category C
Category C
Calcium Channel Blocker
ACE Inhibitor + Calcium Channel Blocker