The antihypertensive effect of captopril in severe essential, renovascular, renal and transplant renovascular hypertension.

The acute and long-term (6 months) effects of captopril (C) were studied in 23 patients with previously uncontrolled severe (DBP greater than 120 mmHg) hypertension of different origin: essential (EH,) n=10, renovascular (RVH) n=9, and renal (RH) n=4. In addition, four patients were treated with renal transplant artery stenosis and hypertension (TRVH), refractory to conventional therapy. Before treatment supine blood pressure (BP, mmHg) averaged: 205/131 (EH), 204/124 (RVH), 207/132 (RH) and 194/117 (TRVH). All patients received diuretics and other antihypertensive drugs, the dosages of which are expressed in arbitrary equivalent units (U) per day (UD = diuretics; UA = other antihypertensive drugs). Antihypertensive therapy before study: UD:EH 1.6; RVH 1.0; UA: EH 7.3; RVH 5.5. After admission, C dosage was increased from 25 mg to a maximum of 150 mg t.i.d. Antihypertensive treatment was reduced as far as possible. DBP decrease after 25 mg C was related to pretreatment PRA in RVH only. After 3 months of C treatment, BP decreased to 190/116 in EH and 145/89 in RVH (EH vs RVH P less than 0.01), 158/98 in RH, and 154/90 in TRVH. After 6 months, BP response was maintained in RH and TRVH. BP increased slightly in RVH to 158/102 mmHg, mainly because of impaired renal function in three patients with bilateral renovascular disease. In EH,BP decreased to 167/109, since three non-responders were taken out of the group. After 6 months, EH still received higher dosages of antihypertensive drugs than RVH. Acute and chronic hypotensive effects of C were not significantly correlated. Side-effects occurred in five patients: skin rash and pruritus [2], taste disturbances [1], proteinuria [1], and acute renal failure in one patient with TRVH. In our hands, captopril in combination with diuretics was significantly more potent in severe RVH than in EH. Dosages and side-effects of other antihypertensive drugs could be markedly reduced in most patients, which may improve long-term drug compliance.