A randomized trial of two etoposide schedules in small-cell lung cancer: the influence of pharmacokinetics on efficacy and toxicity.

Abstract

The 5-day and 8-day regimens had equivalent activity in small-cell lung cancer. A pharmacokinetic association between concentrations of etoposide and response and toxicity was found. Antitumor activity was associated with the maintenance of lower levels of etoposide than found to be associated with hematologic toxicity. This supports the hypothesis that the schedule of etoposide administration may affect efficacy and toxicity, and that prolonged exposure to low concentrations of etoposide may improve the therapeutic ratio for this drug.