Intra-individual comparison of captopril and enalapril in patients undergoing regular haemodialysis.

The acute and long-term efficacy, tolerance and safety of two orally active angiotensin converting enzyme (ACE) inhibitors, captopril (C) and enalapril (E) were compared in patients on regular haemodialysis (RHD). C and E were successively administered for 6 months to 8 RHD patients with hypertension unresponsive to fluid withdrawal and conventional antihypertensive therapy. The fall in blood pressure after a starting dose of 25 mg C or 5 mg E was of the same magnitude. It was not correlated with the initial PRA levels, which were normal in all patients. The mean daily dose of ACE inhibitor was 45 +/- 28 mg during the C period and 19.4 +/- 17.6 mg at the end of the E period. Three patients required additional treatment, comprising beta-blockers and/or calcium antagonists. The individual daily dose of ACE inhibitor, the need for additional treatment and the antihypertensive response achieved were highly correlated during both study periods. During C administration 4 out of 8 patients presented a taste disturbance, which disappeared 2 weeks after substituting E for C. Serum electrolytes, liver enzymes, haemoglobin concentration and white cell and platelet counts remained unchanged throughout both study periods. It is concluded that RHD patients with hypertension are responsive to ACE inhibitors, C and E being equally effective.