Drug Interaction Report

Nelfinavir may significantly increase the blood levels of istradefylline. You may be more likely to experience side effects such as uncontrolled sudden movements (dyskinesia), dizziness, constipation, nausea, hallucinations, unusual urges and insomnia. 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. 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.