| 2021 | Pharmacogenetic interactions of rifapentine plus isoniazid with efavirenz or nevirapine. | Pharmacogenet Genomics | The effect of rifapentine plus isoniazid on efavirenz pharmacokinetics was characterized in AIDS Clinical Trials Group protocol A5279 (NCT01404312). The present analyses characterize pharmacogenetic interactions between these drugs, and with nevirapine.A subset of HIV-positive individuals receiving efavirenz- or nevirapine-containing antiretroviral therapy in A5279 underwent pharmacokinetic evaluations at baseline, and again weeks 2 and 4 after initiating daily rifapentine plus isoniazid. Associations with polymorphisms relevant to efavirenz, nevirapine, isoniazid, and rifapentine pharmacokinetics were assessed.Of 128 participants, 101 were evaluable for associations with rifapentine and its active 25-desacetyl metabolite, 87 with efavirenz, and 38 with nevirapine. In multivariable analyses, NAT2 slow acetylators had greater week 4 plasma concentrations of rifapentine (P = 2.6 × 10) and 25-desacetyl rifapentine (P = 7.0 × 10) among all participants, and in efavirenz and nevirapine subgroups. NAT2 slow acetylators also had greater plasma efavirenz and nevirapine concentration increases from baseline to week 4, and greater decreases from baseline in clearance. CYP2B6 poor metabolizers had greater efavirenz concentrations at all weeks and greater nevirapine concentrations at baseline. None of 47 additional polymorphisms in 11 genes were significantly associated with pharmacokinetics.Among HIV-positive individuals receiving efavirenz or nevirapine, and who then initiated rifapentine plus isoniazid in A5279, NAT2 slow acetylators had greater rifapentine and 25-desacetyl rifapentine concentrations, and greater increases from baseline in plasma efavirenz and nevirapine concentrations. These associations are likely mediated by greater isoniazid exposure in NAT2 slow acetylators. |
| 2019 | Association of Drug Metabolic Enzyme Genetic Polymorphisms and Adverse Drug Reactions in Patients Receiving Rifapentine and Isoniazid Therapy for Latent Tuberculosis. | Int J Environ Res Public Health | Weekly rifapentine and isoniazid therapy (3HP) is the most frequent treatment for latent tuberculosis infection (LTBI). However, the association between major adverse drug reactions (ADRs) and drug metabolic enzyme single-nucleotide polymorphisms (SNPs) remains unclear. In this study, 377 participants who received the 3HP regimen were recruited and examined for genotyping of CYP5A6, CYP2B6, CYP2C19, CYP2E1, and NAT2 SNPs. In our study, 184 participants (48.4%) developed ADRs. Moreover, CYP2C19 rs4986893 (TT vs. CC+CT, odds ratio [OR] [95% CI]: 2.231 [1.015-4.906]), CYP2E1 rs2070676 (CC vs. CG+GG, OR [95% CI]: 1.563 [1.022-2.389]), and CYP2E1 rs2515641 (CC vs. CT+TT, OR [95% CI]: 1.903 [1.250-2.898]) were associated with ADR development. In conclusion, CYP2C19 and CYP2E1 SNPs may provide useful information regarding ADRs in LTBI patients receiving the 3HP regimen. |
| 2015 | Inhibitory Potential of Twenty Five Anti-tuberculosis Drugs on CYP Activities in Human Liver Microsomes. | Biol Pharm Bull | The direct inhibitory potential of twenty five anti-tuberculosis drugs on eight CYP-specific reactions in human liver microsomes was investigated to predict in vivo drug-drug interactions (DDIs) from in vitro data. Rifampicin, rifabutin, and thioacetazone inhibited one CYP reaction. Isoniazid and clofazimine had inhibitory effects on four CYP reactions, and rifapentine, ethionamide, and prothionamide widely inhibited CYP reactions. Based on the inhibition constant (Ki) and the therapeutic total inhibitor concentrations [I]max of eight drugs in human plasma, [I]max/Ki values were calculated to evaluate clinical DDIs. The [I]max/Ki values were 0.20 or less for rifampicin, rifabutin, and thioacetazone; 0.15-2.0 for isoniazid; 0.14-1.5 for rifapentine; 0.29-1.4 for ethionamide; 0.41-2.2 for prothionamide; and 0.12-6.3 for clofazimine. The highest [I]max/Ki values were 2.0 for isoniazid on CYP3A4 [testosterone (T)]; 1.5 for rifapentine on CYP3A4 [midazolam (M)]; 1.4 for ethionamide on CYP2C8; 2.2, 1.8, and 1.3 for prothionamide on CYP2B6, CYP2C19, and CYP2C8, respectively; and 6.3 and 5.7 for clofazimine on CYP3A4 (M) and CYP3A4 (T), respectively. These drugs with high [I]max/Ki values lead to clinical DDIs. Considering the drug regimens for tuberculosis (TB) and co-infection with TB and human immunodeficiency virus, the inhibitory potential for CYP3A4 and CYP2B6 is particularly important. These results suggest that clofazimine and prothionamide are likely to cause clinically relevant DDIs when co-administered with products metabolized by CYP3A4 and CYP2B6, respectively. Isoniazid and rifapentine may cause DDIs with drugs metabolized by CYP3A4. |