CBD and medicines interactions
The medicine classes metabolised by the cytochromes CBD inhibits, with the documented level of vigilance for each.
Simple rule: if your medicine's leaflet warns against grapefruit, the same caution applies to CBD. Both inhibit closely related cytochromes.
Method and limits
CBD inhibits several liver cytochromes, chiefly CYP3A4, CYP2C19 and CYP2C9, the enzymes that clear a large share of common medicines. The classes listed here have documented metabolism through those pathways, from the Epidyolex trial programme and published case reports.
The grapefruit rule of thumb and the pharmacology are detailed in our article on CBD, medicines and the grapefruit effect. This tool never gives individual advice: your pharmacist has your full treatment list, we do not.