Cardiac effects of combination therapy in hypertension.

Control of hypertension and treatment of concomitant pathophysiologic conditions require use of multiple drugs in more than half of all patients. Unfortunately, most studies dealing with cardiovascular effects of antihypertensive drugs have focused on monotherapy. Thus, our knowledge of combination therapy in the treatment of hypertension is, to a great extent, extrapolation from monotherapy. Angiotensin-converting enzyme inhibitors in combination with calcium antagonists should be particularly efficacious in reducing left ventricular hypertrophy. Drug classes that either stimulate the renin-angiotensin system or the sympathetic nervous system are less likely to reduce left ventricular hypertrophy and should be avoided. In hypertensive patients with left ventricular dysfunction, beta-blockers should be combined with angiotensin-converting enzyme inhibitor, whereas in the postmyocardial ischemia patient, verapamil and angiotensin-converting enzyme inhibitors may exert some additional beneficial effects with regard to reinfarction rates. Some of the undesirable metabolic side-effects of diuretics can be mitigated by the addition of an angiotensin-converting enzyme inhibitor or an angiotensin-receptor blocker. Given that two drugs when used separately are beneficial in a disorder does not necessarily mean that their combination is equally or even more beneficial. Sometimes combination therapy is used to counteract different limbs of pathophysiologic cascade operative in hypertensive patients with complications or comorbidities.