Drug Interaction Report

Leniolisib may increase the blood levels of pirfenidone. In some cases, this can increase the risk and/or severity of side effects such as liver problems, sensitivity to sunlight, rash, dizziness, diarrhea, nausea, vomiting, and upset stomach. Talk to your doctor if you have any questions or concerns. Your doctor may be able to prescribe alternatives that do not interact, or you may need a dose adjustment or more frequent monitoring to safely use both medications. You should seek immediate medical attention 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, light colored stools, and/or yellowing of the skin or eyes, as these may be signs and symptoms of liver damage. 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.

Pirfenidone should be taken with food to help reduce dizziness and gastrointestinal side effects such as diarrhea, nausea, vomiting, and upset stomach. Avoid smoking during treatment, as cigarette smoking can reduce the blood levels and effects of pirfenidone. If you are a smoker, you should try to quit smoking before starting treatment. Talk to your doctor or pharmacist if you have any questions or concerns, or need help in finding a smoking cessation program. You should also avoid consuming grapefruit or grapefruit juice while taking pirfenidone, as it may increase blood levels of the medication and lead to more side effects. 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: Coadministration with inhibitors of CYP450 3A4 including grapefruit or grapefruit juice may increase the plasma concentrations of leniolisib, which undergoes extensive CYP450 3A4-mediated first-pass metabolism in the gut wall and liver. In general, the effect of grapefruit juice is concentration-, dose- and preparation-dependent, and can vary widely among brands. Certain preparations of grapefruit juice (e.g., high dose, double strength) have sometimes demonstrated potent inhibition of CYP450 3A4, while other preparations (e.g., low dose, single strength) have typically demonstrated moderate inhibition. Pharmacokinetic interactions involving grapefruit juice are also subject to a high degree of interpatient variability, thus the extent to which a given patient may be affected is difficult to predict.

MANAGEMENT: Patients who regularly consume grapefruit or grapefruit juice should be monitored for adverse effects and altered plasma concentrations of leniolisib. Some authorities recommend to avoid grapefruit products during leniolisib treatment (UK).