Drug Interaction Report

Using allopurinol together with PACLitaxel may increase the effects of PACLitaxel. Contact your doctor if you experience side effects related to decreased bone marrow function and blood problems such as extreme fatigue, easy bruising, or bleeding; black, bloody or tarry stools, fever or chills, or signs of infection such as fever, chills, or sore throat. 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.

Allopurinol should generally be taken after a meal to reduce side effects. If your daily dose exceeds 300 mg, you may also ask your healthcare provider if it is okay to divide the total daily dose into smaller doses given more frequently instead of once a day, as this may also reduce stomach upset that can happen with allopurinol. It is best to avoid or limit the consumption of alcohol, as it can increase drowsiness or other nervous system side effects of allopurinol. You should also avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medication affects you. 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.