Efficacy and adverse effects of captopril in severe refractory hypertension

Eleven patients with severe, treatment-resistant essential or renovascular hypertension were treated with captopril after withdrawal of various multiple drug regimes. If supine diastolic blood pressure remained greater than 90 mm Hg on a maximum daily dose of 450 mg captopril, a diuretic and then a beta-adrenoceptor blocker were added. Patient-volunteered complaints were carefully noted. Mean (+/- SE) systolic and diastolic blood pressures fell from 225 +/- 6.8/131 +/- 4.4 mm Hg on various multiple drug regimes to 182 +/- 9.0/105 +/- 5.0 mm Hg on a regime including captopril. The reported and observed incidence of adverse effects were as follows: maculopapular rash (one patient); urticaria and pruritus (three patients); loss of taste (one patient); tachycardia (four patients); increased frequency of trivial infections (three patients); severe myalgia (one patient); and deterioration in renal function (one patient). However, these patients were able to continue captopril after either temporary withdrawal or dose reduction. Captopril was discontinued permanently in five patients, in two because of poor blood pressure control, in one who developed persistent severe urticaria, and in one because of marked proteinuria. In the fifth patient intractable diarrhoea occurred. Captopril lowers blood pressure very effectively in patients with severe hypertension refractory to other agents. Adverse effects are common but acceptable in this situation where prognosis is poor if blood pressure is not adequately controlled.