Drug Interaction Report

Consumer information for this interaction is not currently available.

MONITOR: Coadministration with fenfluramine may decrease the plasma concentrations and therapeutic efficacy of drugs that are substrates of the CYP450 2B6 and/or CPY3A4 isoenzymes. The proposed mechanism, based on in vitro data, might be increased clearance due to induction of CYP450 2B6 and intestinal CYP450 3A4.

MANAGEMENT: Caution and monitoring are recommended if fenfluramine is used concomitantly with drugs that are substrates of CYP450 2B6 and/or CYP450 3A4, particularly sensitive substrates or those with a narrow therapeutic range. Monitoring for potential loss of therapeutic efficacy is recommended. The prescribing information for concomitant medications may be consulted to assess the benefits versus risks of coadministration, as well as any dosage adjustments that may be required during coadministration and/or following the discontinuation of a CYP450 2B6 and/or CYP450 3A4 inducer.

Cisapride is no longer on the market in the US. Do not take cisapride with any other medication, food, or beverage.

**Cisapride (Propulsid) is no longer marketed in the United States. You should only be taking cisapride if you are obtaining the medication from your doctor though a Limited Access Program developed jointly by the manufacturer and the FDA.**

Using fenfluramine with alcohol can increase the risk of cardiovascular side effects such as increased heart rate, chest pain, or blood pressure changes. In addition, you may also be more likely to experience nervous system side effects such as dizziness, drowsiness, depression, and difficulty concentrating. You should avoid or limit the use of alcohol while being treated with fenfluramine. Do not use more than the recommended dose of fenfluramine, and 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 medication without first talking to your doctor.