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

<b>Background/Objectives</b>: Studies show that SNPs in <i>ABCB1</i> rs2032582 and <i>SLCO1B1</i> rs4149015 affect the PK profile of moxifloxacin, a key drug for MDR-TB. This study aimed to assess the genotype frequencies of <i>ABCB1</i> rs2032582 and <i>SLCO1B1</i> 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. <b>Methods</b>: 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. <b>Results</b>: We recruited 204 MDR-TB patients for PG analysis, with 80 providing PK samples. The majority of the <i>ABCB1</i> and <i>SLCO1B1</i> 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. <b>Conclusions</b>: The major genotype of <i>ABCB1</i> rs2032582 and <i>SLCO1B1</i> rs4149015 was wildtype, and the exposure to moxifloxacin was high but not related to the studied genotype in an Indonesian population.