Give once daily at bedtime. May sprinkle contents on applesauce; do not crush or chew contents. Initially 200mg; may titrate upwards in steps to 300mg, then 400mg if necessary. May start at 100mg in impaired renal or hepatic function, elderly or small patients.
Calcium channel blocker (diphenylalkylamine).
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.
Control mild heart failure (eg, with digitalis, diuretics). AV conduction or neuromuscular transmission disorders. Hepatic or renal dysfunction. Monitor liver function. Hypertrophic cardiomyopathy. Pregnancy (Cat.C). Nursing mothers: not recommended.
Potentiates alcohol, α- and β-blockers, other antihypertensives, digitalis, theophylline, neuromuscular blockers, flecainide, carbamazepine, cyclosporine. Potentiated by grapefruit juice. Avoid disopyramide; quinidine in cardiomyopathy. Potentiated by CYP3A4 inhibitors (eg, erythromycin, ritonavir); antagonized by CYP3A4 inducers (eg, rifampin). Inhalation anesthetics may potentiate cardiac depression. May increase bleeding with aspirin. Monitor theophylline, lithium, cyclosporine.
Hypotension, edema, AV block, bradycardia, CHF, constipation, headache, dizziness, fatigue, dyspepsia, elevated hepatic enzymes, paralytic ileus.