This is a calcium-channel blocker

Indications: mild to moderate hypertension; treatment and prophylaxis of chronic stable angina, vasospastic angina and unstable angina; paroxysmal supraventricular tachycardia; reduction of ventricular rate in atrial flutter/fibrillation.

Cautions: first-degree AV block; acute myocardial infarction complicated by bradycardia; concomitant use of beta-blockers; pregnancy and breast-feeding; grapefruit juice ingestion.

Contra-indications: second-and third- degree AV block; sino-artial block; uncompensated heart failure; bradycardia; porphyria; atrial flutter or fibrillation complicating Wolff-Parkinson-White syndrome.

Side Effects: constipation; flushing; headache; nausea and vomiting; allergic reactions.

Dose: by mouth, supraventricular, tachycardias, 40-120 mg 3 times daily.

Angina, 80-120 mg 3 times daily. Hypertension, 240-480 mg daily in 2-3 divided doses. By slow IV injection over 2 minutes, 5-10 mg with ECG monitoring.

In paroxysmal tachyarrhythmias a further 5 mg after 5-10 minutes if required.