Vasodilator drugs in the treatment of hypertension*

Vasodilator drugs counteract the major haemodynamic abnormality of hypertension, namely, arteriolar constriction. As a group, they tend to cause tachycardia and fluid retention, but these side-effects are variable within the group. Vasodilator drugs are effective in the treatment of the whole range of hypertensive diseases, from severe refractory hypertension to mild hypertension. With increasing recognition of the necessity of treatment in mild asymptomatic hypertension, those vasodilator drugs which can be used on their own, such as prazosin and calcium antagonists, are attractive as initial therapy, because they do not have adverse effects on the levels of atherogenic lipids and other risk factors for vascular disease. The major current use of vasodilator drugs in combination with a thiazide and a beta-adrenoreceptor-blocking drug is in the treatment of moderate-to-severe hypertension.