Obeticholic-Acid Probe Studies Found Weak Midazolam Interaction Under Defined Conditions

An interaction result in healthy volunteers does not directly establish the same effect in a liver-disease population.

What the supplied source reports

Five phase I fixed-sequence studies assessed obeticholic acid with enzyme and transporter probes, including oral midazolam. The investigators described weak interaction with midazolam and weak-to-no effects across several other tested pathways at the examined doses. Most adverse events were mild.

Limits of the evidence

The participants were predominantly healthy men, whereas the intended disease population differed in sex, age and liver status. An interaction study using single probe doses cannot capture every polypharmacy pattern or chronic exposure. Historical treatment descriptions in the paper are not a current regulatory update.

Implications for forensic interpretation

For a retrospective medication opinion, distinguish direct study conditions from extrapolation to cholestasis or cirrhosis. Specify the relevant drug, route, dose and exposure endpoint. A weak average probe interaction cannot be treated as proof that a medically complex patient’s benzodiazepine concentration or response was unaffected.

Source and related reading

Source reviewed: Assessment of Pharmacokinetic Interactions Between Obeticholic Acid and Caffeine Midazolam Warfarin (PMC5599467). Forensic applications above are interpretive analysis of the supplied publication.