Combined therapy with Ca-antagonists and beta-adrenergic receptor blocking agents in chronic stable angina

Calcium channel antagonism and beta blockade in combination--a therapeutic alternative in cardiovascular disorders. A review

Calcium-channel antagonists and beta-adrenergic blocking agents have become important modalities in the cardiovascular therapeutic armamentarium. These drugs are often administered as monotherapy to a wide range of cardiological patients with angina pectoris, hypertension, arrhythmias, congestive heart failure, and other diseases. Since within each class these drugs exhibit pharmacologic differences, it follows that their effectiveness varies in different disease states and that they exhibit a wide variety of side effects. In an attempt to optimize therapy, the individual drugs from these two classes can be combined; and the efficaciousness and side-effect profile of various combinations between calcium-channel antagonists and beta blockers are discussed in this review. Recommendations as to which patients may benefit from a combination and as to which patients may be harmed by the combination therapy will be made. Very few studies have compared the safety and efficacy of a single agent with the combination and with placebo in a controlled randomized fashion. To determine which therapy is superior and to determine which combination one should recommend under what circumstances, such placebo-controlled, randomized trials are a necessity, and will hopefully be performed although the complexity is enormous.

Extent and pharmacokinetic mechanisms of oral atenolol-verapamil interaction in man

Chronic coadministration of oral verapamil with oral atenolol resulted in a variable increase in atenolol steady-state plasma concentrations in a group of 10 patients on chronic maintenance therapy. Individual subjects showed changes in area under the plasma atenolol concentration-time curve (AUC) of more than 100%, however group comparisons did not achieve statistical significance unless normalized for verapamil dose. Renal clearance of atenolol was shown to be decreased by more than 25% in 2 subjects studied using intravenous dosing of atenolol. This interaction is likely to contribute to the documented clinical intolerance of combinations of atenolol and verapamil.

A double blind placebo controlled comparison of verapamil, atenolol, and their combination in patients with chronic stable angina pectoris

The efficacy and effect on cardiac function of verapamil 120 mg three times a day and atenolol 100 mg once a day, singly and in combination, were evaluated in 15 patients with angina pectoris. While they were on the combination treatment four patients withdrew from the study. Episodes of angina pectoris and glyceryl trinitrate consumption were significantly reduced only on the combination. On the combination only four patients developed evidence of ischaemia during exercise compared with seven on verapamil and ten on atenolol. ST segment depression at peak exercise, assessed by 16 point precordial mapping, was reduced by all active treatments from 7.1 on placebo to 2.7, 0.9, and 0.6 mm on atenolol, verapamil, and the combination respectively. Mean left ventricular ejection fraction fell significantly from 60% on placebo to 53% on the combination but was unchanged on verapamil and atenolol. Verapamil was an effective alternative to atenolol; the combination was the most effective treatment but was associated with a significant morbidity.