Comparative Pharmacology
Head-to-head clinical analysis: TIAZAC versus VERELAN PM.
Peer-Reviewed Evidence
Head-to-head clinical analysis: TIAZAC versus VERELAN PM.
TIAZAC vs VERELAN PM
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Diltiazem, a benzothiazepine calcium channel blocker, inhibits calcium ion influx across cardiac and vascular smooth muscle cell membranes, resulting in coronary vasodilation, peripheral vasodilation, decreased myocardial contractility, and decreased AV nodal conduction velocity.
Verapamil is a calcium channel blocker that inhibits the influx of calcium ions across the cardiac and vascular smooth muscle cells, thereby reducing myocardial contractility, sinoatrial and atrioventricular node conduction, and vascular tone.
Oral: 120-360 mg once daily; maximum 540 mg daily.
Verelan PM (verapamil hydrochloride) is an extended-release oral capsule administered once daily at bedtime. Typical adult dose for hypertension is 200 mg to 400 mg once daily at bedtime. Initial dose is 200 mg, titrated upward as needed. Maximum recommended dose is 400 mg daily.
None Documented
None Documented
Terminal elimination half-life is 5-7 hours for immediate-release; for TIAZAC (extended-release), effective half-life is approximately 6-9 hours due to prolonged absorption
Terminal elimination half-life 7.2 ± 1.5 hours after oral administration, prolonged in hepatic impairment (up to 14-16 hours) and elderly; steady-state achieved after 3-4 days.
Renal (2-4% unchanged, 60% as inactive metabolites); Fecal (30%); Biliary (minor)
Primarily hepatic metabolism (>95%), with 3-4% excreted unchanged in urine; biliary/fecal excretion accounts for <1% of unchanged drug.
Category C
Category C
Calcium Channel Blocker
Calcium Channel Blocker