Effect of Other Drugs on YULAREB: CYP3A Inhibitors: Strong and moderate CYP3A4 inhibitors increased the exposure of abemaciclib plus its active metabolites to a clinically meaningful extent and may lead to increased toxicity.
Ketoconazole: Avoid concomitant use of ketoconazole. Ketoconazole is predicted to increase the AUC of abemaciclib by up to 16-fold [see Pharmacology: Pharmacokinetics under Actions].
Other Strong CYP3A Inhibitors: In patients with recommended starting doses of 150 mg twice daily, reduce the YULAREB dose to 100 mg twice daily with concomitant use of strong CYP3A inhibitors other than ketoconazole. In patients who have had a dose reduction to 100 mg twice daily due to adverse reactions, further reduce the YULAREB dose to 50 mg twice daily with concomitant use of strong CYP3A inhibitors. If a patient taking YULAREB discontinues a strong CYP3A inhibitor, increase the YULAREB dose (after 3-5 half-lives of the inhibitor) to the dose that was used before starting the inhibitor. Patients should avoid grapefruit products [see Dose Modification under Dosage & Administration and Pharmacology: Pharmacokinetics under Actions].
Moderate CYP3A Inhibitors: With concomitant use of moderate CYP3A inhibitors, monitor for adverse reactions and consider reducing the YULAREB dose in 50 mg decrements as demonstrated in Table 3, if necessary.
Strong and Moderate CYP3A Inducers: Coadministration of strong or moderate CYP3A inducers decreased the plasma concentrations of abemaciclib plus its active metabolites and may lead to reduced activity. Avoid concomitant use of strong or moderate CYP3A inducers and consider alternative agents [see Pharmacology: Pharmacokinetics under Actions].