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.