RESUMEN
To ameliorate the performance of serum creatinine [SCr] as an estimate of glomeular filtration rate [GFR] and functioning renal mass by blocking secretion with Cimetidine and limiting hyperfiltration with Cilazapril. Twenty renal transplant patients [mean age 37.5 years] with a stable renal function were divided into 2 groups [s. creatinine 1.2 mg]. Baseline renal function was measured by serum creatinine, creatinine clearance [CrCI], Cr51EDTA and repeated 48 hours after Cimetidine 2000 mg/day. The tests were performed again 15 days after the administration of Cimetidine and Cilazapril 2.5 mg/d. As expected SCr rose moderately when tubular secretion was blocked with Cimetidine. Cilazapril, however, failed to induce any modification in SCr, CrCI or Cr51EDTA clearance. In early renal failure, SCr is still an acceptable estimate of GFR in most patients. Cilazapril did not result in significant reduction in GFR [at least acutely]. Long term follow-up is required to verify this point and to demonstrate any additional beneficial effect