Treatment of hypertension after renal transplantation: Long-term efficacy of verapamil, enalapril, and doxazosin

Abstract

Normal blood pressure is a good marker of graft survival after renal transplantation, and effective antihypertensive treatment reduces the progression of graft damage. We conducted a long-term follow-up study of 88 hypertensive renal transplant recipients, all of whom were taking sustained cyclosporine A (CsA) immunosuppression. The patients were treated for at least three years, and initially received 240 mg/day of verapamil (N = 24, group I), 5 mg/day of enalapril (N = 24, group II) or 1 mg/day of doxazosin (N = 40, group III). Baseline creatinine did not differ in the three groups, but proteinuria was higher in the enalapril group (7 patients had proteinuria > 1.5 g/day). Treatment was withdrawn in 5 patients in the verapamil group, 5 in the enalapril group and 2 in the doxazosin group due to drug-related side effects. Blood pressure (BP) control at three years was equivalent in the three groups (systolic BP, group I 157 +/- 12; group II 149 +/- 19; group III 154 +/- 21; diastolic BP, group I 90 +/- 8.7, group II 84 +/- 9.8, group III 90.5 +/- 16; mean BP, group I 113 +/- 7, group II 106 +/- 10, group III 106 +/- 29). Two patients in group I, 3 in group II and 15 in group III required additional antihypertensive drugs. CsA levels increased in the verapamil-treated patients, allowing for an early decrease in CsA doses (1 year doses, 3.3 +/- 1 mg/kg body wt/day in group I, 4.3 +/- 1.6 in group II, 3.7 +/- 1.6 in group III). Six cardiovascular events occurred, 3 in group I, 1 in group II, and 2 in group III patients. One patient died in the enalapril group and another in the doxazosin group. Eight verapamil-treated patients, 8 enalapril-treated patients and 4 doxazosin-treated patients lost their grafts due to biopsy-proven chronic transplant nephropathy. In conclusion, the three antihypertensive agents are effective in reducing blood pressure, with no clear advantage of one above any other. Verapamil allows the CsA dose to be reduced, thus decreasing the cost of immunosupression. Enalapril can be a more effective antiproteinuric agent, but hyperkalemia or impaired allograft function may occur in patients with non-optimal allograft function. Doxazosin offers an excellent safety and efficacy profile, and when not efficient by itself in controlling blood pressure, is an ideal concomitant agent in hypertensive renal transplant patients.