Verapamil Extended-release Generic Name & Formulations
Verapamil HCl 120mg, 180mg+, 240mg+; ext-rel tabs; +scored.
Calcium channel blocker (CCB) (diphenylalkylamine).
Mechanism of Action
Verapamil is a calcium ion influx inhibitor (slow-channel blocker or calcium ion antagonist) that exerts its pharmacologic effects by modulating the influx of ionic calcium across the cell membrane of the arterial smooth muscle as well as in conductile and contractile myocardial cells.
Verapamil Extended-release Indications
Verapamil Extended-release Dosage and Administration
Take with food. Initially 180mg in the AM; may titrate to max 480mg/day in divided doses. Elderly or small patients: initially 120mg in the AM.
<18yrs: not established.
Verapamil Extended-release Contraindications
Severe left ventricular (LV) dysfunction or LV dysfunction treated with β-blockers. Moderate to severe heart failure. Hypotension. Cardiogenic shock. Sick sinus syndrome, 2nd- or 3rd-degree AV block, unless paced. Atrial flutter or fibrillation and an accessory bypass tract.
Verapamil Extended-release Boxed Warnings
Verapamil Extended-release Warnings/Precautions
Control mild ventricular dysfunction (eg, with digitalis, diuretics) before initiation. AV conduction or neuromuscular transmission disorders. Hepatic or renal impairment. Monitor liver function periodically. Hypertrophic cardiomyopathy. Pregnancy. Nursing mothers: not recommended.
Verapamil Extended-release Pharmacokinetics
Verapamil Extended-release Interactions
Potentiates alcohol, β-blockers, other antihypertensives, digitalis, theophylline, neuromuscular blockers, flecainide, carbamazepine, cyclosporine, lovastatin (limit to max 40mg/day), simvastatin (limit to max 10mg/day), atorvastatin (use lower doses). Avoid ivabradine; quinidine in hypertrophic cardiomyopathy; disopyramide within 48hrs before or 24hrs after verapamil. Potentiated by CYP3A4 inhibitors (eg, erythromycin, ritonavir), grapefruit juice; antagonized by CYP3A4 inducers (eg, phenobarbital, rifampin). Inhalation anesthetics may potentiate cardiac depression. May increase bleeding with aspirin. Monitor theophylline, lithium. Concomitant mTOR inhibitors (eg, sirolimus, temsirolimus, everolimus); consider dose reductions of both drugs. Monitor heart rate with concomitant clonidine.
Verapamil Extended-release Adverse Reactions
Constipation, dizziness, nausea, hypotension, headache, edema, CHF, fatigue, dyspnea, bradycardia, AV block, rash, flushing, elevated liver enzymes; rare: paralytic ileus.
Verapamil Extended-release Clinical Trials
Verapamil Extended-release Note
Verapamil Extended-release Patient Counseling