Blood plasma
Blood plasma concentrations may be increased when combined with CYP3A4 inhibitors, possibly leading to more side effects. This has been clinically verified for ketoconazole, which increases lurasidone exposure by a factor of 9, and is also expected for other 3A4 inhibitors such as grapefruit juice. Co-administration of CYP3A4 inducers like rifampicin or St. John's wort can reduce plasma levels of lurasidone and its active metabolite, and consequently decrease the effects of the drug. For rifampicin, the reduction was sixfold in a study.