Effect of low-dose fluconazole on theophylline serum concentrations in healthy volunteers

Objective:To determine whether fluconazole alters theophylline serum concentrations at steady-state in healthy volunteers.Design:Ten healthy subjects were administered controlled-release theophylline 150 mg bid for 10 days. Theophylline serum concentrations were measured at steady-state on day 4 to establish a baseline concentration. Fluconazole 100 mg/d was then administered beginning on day 4 through day 10. Theophylline serum concentrations also were measured on days 7, 9, and 11 of the study. Mean theophylline serum concentrations were compared before and during fluconazole administration. Statistical analysis was performed using repeated measures ANOVA.Setting:This study was undertaken in the outpatient department at the Tucson Veterans Affairs Medical Center.Results:No statistically significant differences in mean theophylline serum concentrations were noted on days 7, 9, and 11 compared with baseline.Conclusions:These data show that fluconazole 100 mg/d had no significant effect on theophylline ser...