To ascertain if hepatic or renal dysfunction leads to increased toxicity at a given dose of gemcitabine and to characterize the pharmacokinetics of gemcitabine and its major metabolite in patients with such dysfunction.

Adults with tumors appropriate for gemcitabine therapy and who had abnormal liver or renal function tests were eligible. Patients were assigned to one of three treatment cohorts: I-AST level less than or equal to two times normal and bilirubin level less than 1.6 mg/dL; II-bilirubin level 1.6 to 7.0 mg/dL; and III-creatinine level 1.6 to 5.0 mg/dL with normal liver function. Doses were explored in at least three patients within each cohort. Gemcitabine and its metabolite were to be measured in the blood in all patients.

Forty patients were assessable for toxicity. Transient transaminase elevations were observed in many patients but were not dose limiting. Patients with AST elevations tolerated gemcitabine without increased toxicity, but patients with elevated bilirubin levels had significant deterioration in liver function after gemcitabine therapy. Patients with elevated creatinine levels had significant toxicity even at reduced doses of gemcitabine, including two instances of severe skin toxicity. There were no apparent pharmacokinetic differences among the three groups or compared with historical controls.

If gemcitabine is used for patients with elevations in AST level, no dose reduction is necessary. Patients with elevated bilirubin levels have an increased risk of hepatic toxicity, and a dose reduction is recommended. Patients with elevated creatinine levels seem to have increased sensitivity to gemcitabine, but the data are not adequate to support a specific dosing recommendation.