An interaction measured with midazolam cannot be assigned to every medicine taken with the same inhibitor. Different probe drugs can reveal very different changes in exposure.

What changed as the ASP8477 dose increased

A clinical study used four probe drugs to assess activity of different cytochrome P450 enzymes. At the 100-milligram dose of ASP8477, the geometric mean exposure ratios compared with the probes alone were 158% for midazolam, 190% for losartan, 610% for omeprazole and 555% for dextromethorphan. These ratios refer to area under the concentration–time curve. For example, 158% means 1.58 times the comparator exposure.

Match the estimate to the probe

Midazolam served as the CYP3A probe and omeprazole as the CYP2C19 probe. The two results quantify different interactions under the study’s conditions. To evaluate a proposed interaction in a case, match the drug, metabolic pathway and dose before applying the number. This study measured drug exposure and did not quantify clinical impairment.

Source

Clinical interaction study of ASP8477 using the Inje cocktail (full text) · DOI