Pharmacokinetics of bredinin in renal transplant patients.

A pharmacokinetic study of bredinin, a new immunosuppressive agent, was carried out in 28 renal transplant patients. Serum bredinin concentration-time curves were analyzed using a one-compartment open model with a first order absorption process. The peak serum bredinin level appeared 2.4 h after oral administration of bredinin 50-200 mg. The calculated mean peak serum level was 0.852 micrograms/ml/mg/kg, when the dose was adjusted to the body weight of the patient. In the dosage range used of 0.85-4.46 mg/kg, a linear relationship was observed between the dose and the peak serum bredinin level. The elimination rate of bredinin from serum was dependent on kidney function, and the elimination rate constant was well correlated with the endogenous creatinine clearance. No circadian rhythm was apparent in the elimination rate constant. The absorption rate of bredinin from the gastrointestinal (GI) tract was affected by GI diseases. The need for dosage adjustment based on the renal function of the transplant patient is suggested.