Metoprolol: a Pharmacoeconomic and Quality-of-life Evaluation of Its Use in Hypertension, Post-myocardial Infarction and Dilated Cardiomyopathy

Metoprolol is a beta 1-selective adrenoceptor antagonist that is widely used in several indications. A recent investigation has also highlighted a potential role for metoprolol in selected patients with idiopathic dilated cardiomyopathy. Pharmacoeconomic and quality-of-life data for metoprolol are limited to the areas of hypertension, post-myocardial infarction and idiopathic dilated cardiomyopathy. In these settings, metoprolol has shown beneficial effects on morbidity and mortality, or closely-related end-points. Controlled release formulations offer the potential to maximise the confirmed antihypertensive benefits of metoprolol by maintaining clinically effective plasma drug concentrations within a narrow range over a 24-hour interval between doses. Recent data support the use of controlled release metoprolol at the low dose of 50 mg/day. Metoprolol is at least as effective as many other antihypertensive drugs, although compared with thiazide diuretics at relatively high doses in the MAPHY (Metoprolol Atherosclerosis Prevention in Hypertensives) trial, metoprolol was associated with a more favourable effect on mortality. Pharmacoeconomic analysis, also based on the MAPHY trial, indicates that metoprolol is more cost effective than high dose thiazide diuretics in middle-aged men with mild to moderate hypertension. However, the advantage for beta-blockade in this trial is not supported by results of other studies, and the applicability of these data to current medical practice using lower thiazide doses is therefore questionable. Quality of life in patients with mild to moderate hypertension did not deteriorate in most investigations with metoprolol. Furthermore, quality of life was similar for controlled release metoprolol and atenolol. With conventional/matrix-based sustained release metoprolol, quality of life was less satisfactory than with lisinopril but was only marginally different from that with diltiazem (at lower than usual therapeutic doses). Nevertheless, these newer agents have no proven beneficial effect on mortality, and further studies are also warranted with controlled release metoprolol 50 mg/day. When administered post-myocardial infarction, conventional metoprolol was associated with significant improvements in quality of life and was cost saving over a 3-year period. Significant improvements in quality of life were also evident for metoprolol-treated patients with idiopathic dilated cardiomyopathy. In summary, available data support the continued extensive usage of metoprolol as treatment for hypertension and as therapy post-myocardial infarction. Pharmacoeconomic data supporting an advantage for metoprolol over high dose thiazides in hypertension needs further assessment in settings reflecting usual general practice approaches to managing patients with hypertension, while differences in quality of life between metoprolol and other antihypertensive agents appear to be marginal.(ABSTRACT TRUNCATED AT 400 WORDS)