[Renin-angiotensin-aldosterone system inhibition: pharmacologic rationale and evaluations of drug combinations].

First-line antihypertensive monotherapy is effective in normalizing blood pressure in approximatively 50 per cent of patients. Normalization in the remaining patients may require a combination of two or more drugs. This review considers the rationale and the evaluation of combinations with drugs interacting with the renin-angiotensin system (i.e. angiotensin-converting enzyme inhibitors (ACEI) and angiotensin receptor antagonists) with other drugs. The combinations may be justified when giving an additive or synergistic action and when reducing clinical or metabolic side-effects. Recent developments concern the potential benefit of combining ACEI and angiotensin receptor antagonists.