Comparative Pharmacology
Head-to-head clinical analysis: CALAN versus CARDIZEM SR.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CALAN versus CARDIZEM SR.
CALAN vs CARDIZEM SR
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Verapamil inhibits calcium ion influx through voltage-gated L-type calcium channels in cardiac and vascular smooth muscle, leading to decreased myocardial contractility, slowed AV conduction, and vasodilation.
Diltiazem inhibits calcium ion influx across cardiac and vascular smooth muscle cell membranes during depolarization, leading to negative inotropic, chronotropic, and dromotropic effects, and vasodilation.
Initial: 80-120 mg orally 3 times daily; maintenance: 240-480 mg/day in 3-4 divided doses. IV: 5-10 mg over 2 minutes, may repeat after 15-30 minutes.
Oral: Initial dose 60-120 mg twice daily; titrate to maximum 360 mg/day divided into two doses.
None Documented
None Documented
Terminal elimination half-life is 3-7 hours for immediate-release; can be prolonged to 12-16 hours with sustained-release due to slow absorption; increased in hepatic impairment.
3.0-4.5 hours for diltiazem; metabolites (e.g., desacetyldiltiazem) up to 10 hours. Clinical context: dosing interval adjustment in hepatic impairment.
Approximately 70% renal (3-4% unchanged, remainder as metabolites) and 25% biliary/fecal.
Renal: 2-4% unchanged; hepatic metabolism: ~60-70% (including active metabolites); fecal: ~30-40%.
Category C
Category C
Calcium Channel Blocker
Calcium Channel Blocker