Drug Interaction Report

Consumer information for this interaction is not currently available.

MONITOR: Coadministration with weak inhibitors of CYP450 3A4 may increase the plasma concentrations and adverse effects of palovarotene, which is primarily metabolized by the isoenzyme. Pharmacokinetic modeling simulations suggest that coadministration of palovarotene with cimetidine, a weak CYP450 3A4 inhibitor, resulted in a slight increase in the Cmax and AUC of palovarotene of approximately 10%; however, the clinical significance is unknown. Increased concentrations of palovarotene may increase the risk of adverse effects such as dry skin, dry lips, alopecia, pruritus, erythema, paronychia, cellulitis, decubitus ulcer, xerophthalmia, night blindness, depression, mood alterations, and pseudotumour cerebri (benign intracranial hypertension).

MANAGEMENT: Caution and clinical monitoring are recommended if palovarotene is coadministered with weak CYP450 3A4 inhibitors. The benefits versus risks of coadministration should be assessed. Patients should be advised to notify their health care professional if they experience increased effects of palovarotene such as dry skin, dry lips, alopecia, pruritus, erythema, paronychia, cellulitis, decubitus ulcer, xerophthalmia, night blindness, depression, mood alterations, and pseudotumor cerebri.

Grapefruit, pomelo, and juices or supplements containing these fruits may increase the blood levels of palovarotene, which may increase the risk and/or severity of side effects such as dry skin, dry lips, hair loss, skin rash, itching, skin and nail infection, dry eyes, night blindness, depression, and mood changes. It may also increase the risk of a rare, but potentially serious, condition called pseudotumor cerebri caused by increased pressure in the brain. Palovarotene should be taken with food at approximately the same time each day. Talk to your doctor if you have any questions or concerns. Your doctor may be able to prescribe alternatives that do not interact. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

You may want to limit your consumption of grapefruit or grapefruit juice during treatment with hydroxychloroquine. Grapefruit juice can significantly increase the blood levels and effects of hydroxychloroquine, which may result in an irregular heart rate or other conduction disturbances. Hydroxychloroquine should also be taken with food or milk to reduce the incidence of stomach upset. Talk to your doctor if you have any questions or concerns. You should seek immediate medical attention if you develop sudden dizziness, lightheadedness, fainting, shortness of breath, or heart palpitations during treatment with hydroxychloroquine. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.