Peritoneal Clearances in Hypertensive Capd Patients after Oral Administration of Clonidine, Enaldpril, and Nifedipine

Abstract

The authors investigated whether the reduction of arterial pressure, induced by the oral administration of clonidine (CLO), enalapril (EN), and nifedipine (NIF), has any effect on peritoneal transport rates. The study was performed in nine hypertensive patients undergoing continuous ambulatory peritoneal dialysis (CAPD). The patients were submitted to administration of CLO, EN, and NIF, each in randomized succession for two weeks, after withdrawal of any hypotensive therapy for eight days (washout period). The nine patients underwent a four-hour dwell exchange using a 2.27 g/dL glucose two-liter bag after washout and after each hypotensive period. The following parameters were analyzed: mean arterial pressure (MAP), performed in the sitting position; net ultrafiltration; effluent/initial dialysate glucose ratio (GL DIDo); peritoneal clearance of K, BUN, creatinine (Cr), phosphate, beta-2 microglobulin (β2), total proteins, and the ratio between B2 and Cr clearance. Moreover, residual renal Cr and B2 clearances were analyzed. The three drugs significantly reduced MAP at a similar rate. The peritoneal transport parameters after CLO were similar to the results in the washout period. On the contrary, after EN and NIF therapy, Crand B2 clearances were significantly increased, and GL DIDo decreased in comparison to the washout period. The other peritoneal transport parameters after EN and NIF were similar to the washout period. Residual renal Cr and B2 clearances after the three drugs were similar to those in the washout. These data suggest that after two weeks of therapy with EN and NIF, glucose, Cr, and B2 peritoneal transports are influenced by these hypotensive drugs irrespective of the effect on the arterial pressure. These observations may have implications for hypotensive drug selection in CAPD hypertensive patients.