Pharmacogenetics and Pharmacokinetics of Moxifloxacin in MDR-TB Patients in Indonesia: Analysis for ABCB1 and SLCO1B1.

Background/Objectives: Studies show that SNPs in ABCB1 rs2032582 and SLCO1B1 rs4149015 affect the PK profile of moxifloxacin, a key drug for MDR-TB. This study aimed to assess the genotype frequencies of ABCB1 rs2032582 and SLCO1B1 rs4149015; describe moxifloxacin AUC(0-24) and C(max); and evaluate the association between genotype variations and moxifloxacin AUC(0-24) and C(max), corrected for the effect of other determinants in MDR-TB patients in Indonesia. Methods: The genotypes were identified using DNA sequencing. Plasma samples for PK analysis were collected at either two or four timepoints post-dose, at steady state. AUC(0-24) values were assessed with a limited sampling formula. A multivariate linear regression analysis identified the determinants for moxifloxacin AUC(0-24) and C(max). Results: We recruited 204 MDR-TB patients for PG analysis, with 80 providing PK samples. The majority of the ABCB1 and SLCO1B1 genotypes were wildtype (GG), 41.7% and 93.6%, respectively. The geometric mean AUC(0-24) for moxifloxacin was 78.6 mg·h/L and that for C(max) was 6.1 mg/L. No statistically significant difference in exposure to moxifloxacin could be shown between the genotypes. Sex, age, and dose in mg/kg/body weight were significant determinants of the AUC(0-24) of moxifloxacin. Conclusions: The major genotype of ABCB1 rs2032582 and SLCO1B1 rs4149015 was wildtype, and the exposure to moxifloxacin was high but not related to the studied genotype in an Indonesian population.