Probably not. If the grapefruit is coming into your system 12 hours after the drug, the drug's already been processed by the P450 system. I think the odd coinci

Probably not. If the grapefruit is coming into your system 12 hours after the drug, the drug's already been processed by the P450 system. I think the odd coincidence here is that grapefruit is a "breakfast food" and thus people take it with their morning meds.