Drug Interaction Report

Istradefylline may increase the blood levels and effects of topotecan. You may need a dose adjustment or more frequent monitoring by your doctor to safely use both medications. Contact your doctor if your condition changes or you experience increased 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.

Smoking tobacco may reduce the blood levels and effects of istradefylline. Contact your doctor if istradefylline is not adequately controlling your symptoms. It is best to avoid smoking during istradefylline therapy. Talk to a healthcare professional if you have any questions or concerns. If you start smoking or undergo smoking cessation, your doctor may need to monitor you more closely to determine if you need a dose adjustment of istradefylline. Your doctor may already be aware of the risks and may have taken appropriate precautions including adjusting your dose and monitoring you closely for any potential complications. 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.