CIMETIDINE OR RANITIDINE IN RENAL-TRANSPLANT PATIENTS RECEIVING CYCLOSPORINE

While H-2-receptor antagonists are commonly used in renal transplant p atients to prevent peptic ulcer disease, they have been associated wit h immunostimulation, interference with cyclosporine (CsA) metabolism, and inhibition of tubular secretion of creatinine. In renal transplant patients, cimetidine in high doses has been shown to cause a sustaine d rise in serum creatinine (S-Cr) and to reduce creatinine clearance ( CrCl) with no change in inulin clearance. In this short-term prospecti ve study, we evaluated the effects of single daily doses of cimetidine or ranitidine on renal function, and CsA serum concentration. Fourtee n renal transplant patients with stable renal function were assigned t o receive either cimetidine 400 mg daily or ranitidine 150 mg daily fo r 7 days, In patients who received cimetidine, a slight rise in S-Cr w as observed at days 2 and 5 which was not statistically significant, b ut no significant change in CsA trough level was noted. No changes in S-Cr or CsA level were noted in the patients who received ranitidine. No changes in GFR were observed in either cimetidine- or ranitidine-tr eated patients. We conclude that, in our short-term study, cimetidine or ranitidine in the doses used in this study did not affect the GFR o r CsA level, or S-Cr.