[The role of diuretics in antihypertensive therapy]

Hypertensive therapy based on diuretics is time-honored. Thiazides represent the most commonly used class of diuretics for uncomplicated hypertension because of economic motivations, their tolerance and efficacy both as monotherapy and in combined treatment with other agents. Clinical studies using diuretics and beta-blockers reported that thiazide treatment prevents the development of malignant hypertension, renal and heart failure, hypertensive retinopathy, and reduces in five years overall mortality of 33%, cardiovascular mortality of 41%, fatal and non-fatal cerebrovascular events of 51% and the risk of coronary events of 15%. The less than expected risk reduction of cardiovascular disease raised many concerns about the possibility of adverse biochemical changes of thiazides through their effects on lipids, electrolytes and glucose metabolism. However, the real clinical significance of these metabolic effects remains actually uncertain and needs further investigation. The treatment of the hypertensive patient cannot be adequately managed using a merely adjunctive step-care criterium. Hypertensive subjects have different haemodynamic, metabolic and endocrine disorders and a tailored treatment should consider the different activities of the various agents as monotherapy or in association in the single patient.