Video lessons, equations, calculators and a weekly literature list on ADME and DMPK. Each lesson works from published clinical and in vitro data and cites the primary sources.
In the IMPAACT 2001 study, the ratio of breast milk to maternal plasma concentration was 0.0236 for rifapentine and 0.0411 for its metabolite desacetyl rifapentine, and the estimated maximum relative infant dose was below 1%. Rifapentine crossed the placenta, but the authors judge the infant plasma concentrations unlikely to be clinically significant.
In 47 women, the unbound intrinsic formation clearance of 6β-hydroxycortisol increased 1.8-fold in late pregnancy, which corresponds to a 2.1-fold increase in hepatic CYP3A activity. The authors propose this endogenous biomarker for future studies of CYP3A activity across pregnancy and postpartum.
In 891 samples from 213 patients, low cenobamate doses (12.5 to 50 mg/day) increased serum brivaracetam concentrations by 32%, and high doses (250 to 450 mg/day) decreased them by 21%. Cenobamate inhibits CYP2C19, an enzyme of brivaracetam metabolism, and the authors ask for prospective studies of the clinical relevance.