[The pharmacokinetics of rifampicin in the intermittent treatment of patients with pulmonary tuberculosis. 1. Excretion of rifampicin in the urine].

With a rifampicin (RMP) range of 600 to 1800 mg, 12.5% of the administered dose are on an average secreted in urine. In spite of this minimal portion the course of pharmacokinetic processes can distinctly be learned from its alterations. Analyses in 84 patients revealed that the age will influence the induction and the sex-specific differences of the pharmacokinetics. Compared to male subjects, an increased RMP secretion in urine can be recorded in young female subjects, whereas in older male ones an induction-reduced RMP elimination in urine becomes more obviously. Considering these multiform processes, the determination of the bioavailability of RMP preparations by means of the RMP secretion in urine is taken to be manipulatable and uncertainly. More evident results can be gained by the determination of the RMP concentration in serum or by the calculation of the AUC.