calan

Calan is a brand name for verapamil hydrochloride, a calcium channel blocker used to treat certain cardiovascular conditions. Verapamil belongs to the phenylalkylamine class and exerts its effect by inhibiting L-type calcium channels in cardiac and smooth muscle.

By blocking calcium entry into cells, verapamil reduces myocardial contractility, slows conduction through the atrioventricular (AV) node, and relaxes vascular smooth muscle. These actions lower heart rate and blood pressure and reduce the heart’s workload, helping to relieve angina and control certain arrhythmias.

Common medical uses include essential hypertension, chronic stable angina, vasospastic (Prinzmetal) angina, and certain supraventricular tachyarrhythmias where rate control is desired. Calan is available in immediate-release form and as sustained-release preparations for oral use; an intravenous form may be used in hospital settings for acute management.

Contraindications include severe hypotension, second- or third-degree AV block, sick sinus syndrome without a pacemaker, cardiogenic shock, and decompensated heart failure. Cautions apply to patients with reduced left ventricular function, hepatic impairment, or concomitant use of other negative inotropic or nodal-blocking agents; monitoring of heart rate and blood pressure is advised during therapy.

Common adverse effects are constipation, dizziness, headache, flushing, edema, and bradycardia; gingival overgrowth can occur with prolonged use. Drug interactions include additive hypotension with other antihypertensives and heart-rate-lowering drugs such as beta blockers or digoxin, and metabolic interactions via CYP3A4 with inhibitors or inducers, as well as potential effects with grapefruit juice. Use during pregnancy or lactation should be guided by a healthcare provider.