Verapamil
Brand: Calan (US) / Isoptin (IN/BD) / Covera-HS (EU)
Antihypertensive
Calcium channel blocker (Phenylalkylamine)
Pharmacokinetics
| Half-life | 6 hours |
| Tmax | 1.5 h |
| Bioavailability | 22 % (approx) |
| Protein Binding | 90 % |
| Volume of Distribution | 3.8 L/kg (approx) |
| Clearance Route | hepatic |
| Active Metabolites | yes |
| Notes | Undergoes extensive first-pass metabolism; sustained-release forms extend t½; used in supraventricular tachycardia and angina. |
⚠️ Safety & Warnings
Severity: Moderate
Adverse Effects:
Constipation, bradycardia, AV block, hypotension, dizziness
Contraindications:
Severe left ventricular dysfunction, hypotension, AV block, sick sinus syndrome
Precautions:
Avoid with β-blockers; monitor ECG and heart rate; caution in hepatic impairment