- CYP3A4 Inhibitors/Inducers/Substrates Dasatinib is primarily metabolized by the CYP3A4 enzyme. Therefore, potent inhibitors of CYP3A4 are prohibited during study; for such medications, a wash-out period of ≥ 7 days is required prior to starting dasatinib. Subjects should be advised not to consume substantial quantities of grapefruit juice.