The pharmacokinetics of oral rifampicin in AIDS patients.

Previous studies in AIDS patients have shown that the peak serum concentration of rifampicin at 2 hours after administration are below normal ranges. These may be due to malabsorption of the drug resulting in therapeutic failure. However, there is no published data to demonstrate the pharmacokinetics of rifampicin in these AIDS patients. Therefore, the aim of this study was to provide such data. Eight AIDS patients with tuberculosis participated in this study. All patients were scheduled to receive oral rifampicin 600 mg once daily in the morning on an empty stomach. Rifampicin pharmacokinetics were studied on day 14. The mean Cmax was 9.81 +/- 4.41 ug/ml. The mean Tmax was 2.25 +/- 0.71 h. The mean AUC0-24 was 60.25 +/- 36.88 ug.h/ml. The results of our study did not confirm the previous studies. The absorption of rifampicin in most of our AIDS patients were not reduced and delayed. Therefore, rifampicin dosage adjustment for Thai patients may not be necessary.