Comparative Pharmacology
Head-to-head clinical analysis: CARDIZEM versus ISOPTIN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CARDIZEM versus ISOPTIN.
CARDIZEM vs ISOPTIN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Diltiazem inhibits calcium influx into cardiac and vascular smooth muscle cells during depolarization by binding to L-type calcium channels. This results in coronary vasodilation, decreased myocardial oxygen demand, and negative chronotropic and inotropic effects.
Verapamil inhibits calcium ion influx across cardiac and vascular smooth muscle cells, blocking L-type calcium channels, leading to vasodilation and reduced myocardial contractility and conduction velocity.
Oral: 30-120 mg three to four times daily; extended-release: 120-360 mg once daily. IV: Initial 0.25 mg/kg (max 25 mg) bolus over 2 minutes, may repeat in 15 minutes (0.35 mg/kg); maintenance: 5-15 mg/hour continuous infusion.
Initial dose: 80-120 mg orally three times daily; sustained-release: 120-240 mg orally once daily. IV: 5-10 mg slow IV push over 2 minutes, may repeat after 15-30 minutes. Maximum daily oral dose: 480 mg.
None Documented
None Documented
Terminal elimination half-life is 3.0-4.5 hours in healthy adults; may be prolonged to 7-9 hours in elderly, hepatic impairment, or renal impairment; clinically relevant for dosing frequency.
Terminal elimination half-life: 4.5-12 hours (mean 8 hours); increases with hepatic impairment or cirrhosis
Primarily hepatic metabolism with extensive first-pass effect; approximately 2-4% excreted unchanged in urine; fecal excretion accounts for about 65% of dose as metabolites; renal excretion accounts for about 35% of dose as metabolites.
Renal (70% as metabolites, 3-5% unchanged); biliary/fecal (25%)
Category C
Category C
Calcium Channel Blocker
Calcium Channel Blocker