Cyclosporine (cyclosporin A) pharmacokinetics in renal transplant patients receiving ciprofloxacin.

The effects of ciprofloxacin administration on the pharmacokinetic parameters and biologic tolerance of cyclosporine (cyclosporin A) were determined in primary renal transplant patients. This study was performed in 10 patients (four women and six men) ranging in age from 26 to 64 years and body weight ranging from 46 to 88 kg. Ciprofloxacin therapy was started eight to 48 days (mean, 21 days) after transplantation, whereas the cyclosporine therapy was administered for seven to 48 days (mean, 18 days) post-transplant. Both ciprofloxacin and cyclosporine were administered every 12 hours. The mean cyclosporine dosage was 2.4 mg/kg per day, adjusted to obtain blood concentrations within the recommended range (i.e., 100 to 200 ng/ml). The ciprofloxacin dosage was 750 mg orally twice daily for all patients. A pharmacokinetic study of cyclosporine was performed in each patient the day before starting ciprofloxacin treatment and after the 13th ciprofloxacin administration (i.e., Day 7 of ciprofloxacin therapy). Cyclosporine concentrations were measured in whole blood by a specific high-performance liquid chromatography method and the following parameters were determined: minimal and maximal blood concentrations, area under the curve from zero to 12 hours, total body oral clearance, mean residence time, and elimination half life. Concurrently administered medications and serum creatinine values were recorded. No statistically significant difference was noted between the cyclosporine pharmacokinetic parameters before and during ciprofloxacin treatment. Serum creatinine levels were increased in four of 10 patients, but the increase was not considered related to ciprofloxacin treatment. In conclusion, it appears that ciprofloxacin can be administered to renal transplant patients without risk of interacting cyclosporine or enhancement of cyclosporine nephrotoxicity. Additional cyclosporine blood level monitoring is not particularly valuable in this setting.