Pharmacokinetics of prothionamide in patients with multidrug-resistant tuberculosis

SETTING: National Masan Tuberculosis Hospital, Masan, South Korea. OBJECTIVE: To evaluate the pharmacokinetics of prothionamide (PTH) in South Korean patients with multidrug-resistant tuberculosis (MDR-TB) and to investigate whether differences in body mass index (BMI) could explain observed differences in PTH disposition. DESIGN: Seventeen patients participated in the study; all had MDR-TB and had received combination anti-tuberculosis treatment, including PTH, cycloserine, ofloxacin, para-aminosalicylic acid and streptomycin or kanamycin, for at least 2 weeks. The patients were divided into two groups based on BMI: Group A (18.5 ≤S BMI < 23), and Group B (BMI < 18.5). Serum samples were collected over 24 h, and the plasma PTH concentration was determined by a validated high-performance liquid chromatography assay. RESULTS: After steady-state administration of PTH, the mean area under the plasma concentration-time curve from time 0 to 12 h (AUC_0-12h) was 11.0 ± 3.7 μg h/ml. The mean T_max and t_1/2 were respectively 3.6 h and 2.7 h. No significant difference in PTH disposition was observed between groups A and B, except for ke and t_1/2. CONCLUSION: In the pharmacokinetic parameter estimates for PTH in MDR-TB patients during routine treatment, the pharmacokinetics of PTH did not appear to correlate with extent of emaciation in MDR-TB patients.