Drug Interaction Report

Idelalisib may cause serious and life-threatening diarrhea, and using it with other medications that also commonly cause diarrhea such as PACLitaxel may increase that risk. Talk to your doctor if you have any questions or concerns. Your doctor may already be aware of the risks, but has determined that this is the best course of treatment for you and has taken appropriate precautions and is monitoring you closely for any potential complications. Call your doctor immediately if the number of bowel movements per day increases by six or more, or if you experience new or worsening abdominal pain, chills, fever, nausea, or vomiting. You may need a dose adjustment or an interruption in idelalisib therapy if you develop severe diarrhea. 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.

Grapefruits and grapefruit juice may increase the blood levels and effects of PACLitaxel. This can increase the risk of side effects such as nausea, diarrhea, hair loss, muscle pain or weakness, nerve damage, and impaired bone marrow function resulting in low numbers of different types of blood cells. You may also be more likely to develop anemia, bleeding problems, or infections due to low blood cell counts. Contact your doctor if you experience paleness, fatigue, dizziness, fainting, unusual bruising or bleeding, fever, chills, diarrhea, sore throat, muscle aches, shortness of breath, blood in phlegm, weight loss, red or inflamed skin, body sores, pain or burning during urination, vision problems, and/or numbness, burning or tingling in your hands and feet. You may need a dose adjustment and/or more frequent monitoring by your doctor to safely use both medications. 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.