What are the current clinical uses of calcium channel antagonists?
Verapamil Verapamil is effective as monotherapy for angina provided that it does not cause cardiac failure. Verapamil is also used in the treatment of hypertension. It is effective in reducing blood pressure either as monotherapy or in combination with either diuretics or ACE inhibitors. Combination with a beta blocker is not recommended because of additive deleterious myocardial depression. Compared with the other calcium channel antagonists, the limiting factors for the use of verapamil in hypertension are its cardiodepression and the almost universal occurrence of constipation. Verapamil has a unique role among the calcium channel antagonists in the management of supraventricular arrhythmias. Normal conduction through the AV node is dependent on calcium entry into the conducting tissue cells for depolarisation. Verapamil reduces calcium entry and thus slows AV conduction. This action can be beneficial in terminating or preventing paroxysmal supraventricular tachycardia by interferin