Comparative Pharmacology
Head-to-head clinical analysis: CARDIZEM versus CARDIZEM SR.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CARDIZEM versus CARDIZEM SR.
CARDIZEM vs CARDIZEM SR
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.
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.
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.
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 3.0-4.5 hours in healthy adults; may be prolonged to 7-9 hours in elderly, hepatic impairment, or renal impairment; clinically relevant for dosing frequency.
3.0-4.5 hours for diltiazem; metabolites (e.g., desacetyldiltiazem) up to 10 hours. Clinical context: dosing interval adjustment in hepatic impairment.
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: 2-4% unchanged; hepatic metabolism: ~60-70% (including active metabolites); fecal: ~30-40%.
Category C
Category C
Calcium Channel Blocker
Calcium Channel Blocker