Drug Interactions between pazopanib and tofacitinib

Do not consume grapefruit or grapefruit juice during treatment with PAZOPanib unless directed otherwise by your doctor. Grapefruit juice can increase the blood levels of PAZOPanib, which may lead to an increased risk of serious side effects such as liver damage, irregular heart rhythm, bleeding, high blood pressure, heart attack, and stroke. Taking PAZOPanib with food can also significantly increase its absorption and levels in the blood. Therefore, you should take PAZOPanib on an empty stomach, at least one hour before or two hours after eating. Call your doctor immediately if you develop fever, chills, joint pain or swelling, unusual bleeding or bruising, skin rash, itching, loss of appetite, fatigue, nausea, vomiting, dark colored urine, and/or yellowing of the skin or eyes, as these may be signs and symptoms of liver damage. You should also seek immediate medical attention if you experience signs and symptoms that could indicate cardiovascular problems such as sudden dizziness; lightheadedness; fainting; fast or pounding heartbeats; chest pain or tightness; pain in your arms, back, neck, or jaw; shortness of breath; numbness or weakness on one side of your body; and slurred speech or difficulty speaking. 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.

Consumer information for this interaction is not currently available.

MONITOR: Grapefruit juice may increase the plasma concentrations of tofacitinib. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. The extent and clinical significance are unknown. Moreover, pharmacokinetic alterations associated with interactions involving grapefruit juice are often subject to a high degree of interpatient variability.

MANAGEMENT: Until more information is available, some authorities recommend avoiding consumption of grapefruit juice during tofacitinib therapy (Canada). Patients receiving tofacitinib therapy who ingest grapefruits or grapefruit juice should be monitored for adverse effects and undue fluctuations in plasma drug levels.