Drug interactions
Fenfluramine + Meperidine
Severity: Major
Fenfluramine and Meperidine: major interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Both drugs raise serotonergic activity, so combined use may precipitate serotonin syndrome with agitation, hyperthermia, clonus and autonomic instability. Fenfluramine's labeling warns of serotonin syndrome with serotonergic drugs, and meperidine is among the opioids implicated. Sedation may also be additive.
What this interaction means in plain words
Fenfluramine and Meperidine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Fenfluramine belongs to Central Nervous System; Meperidine belongs to Musculoskeletal.
Why it happens
Additive serotonergic effects from serotonin release by fenfluramine and serotonin reuptake inhibition by meperidine.
What to do
Avoid the combination and choose a non-serotonergic opioid such as morphine. If used, monitor for serotonin toxicity and stop both drugs if it occurs.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Fenfluramine and Meperidine, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
Other interactions of Meperidine
- Alvimopan + Meperidine Contraindicated
- Isocarboxazid + Meperidine Contraindicated
- Meperidine + Methylene blue Contraindicated
- Meperidine + Olanzapine / samidorphan Contraindicated
- Meperidine + Phenelzine Contraindicated
- Meperidine + Procarbazine Contraindicated
Other interactions of Fenfluramine
- Fenfluramine + Isocarboxazid Contraindicated
- Fenfluramine + Linezolid Contraindicated
- Fenfluramine + Phenelzine Contraindicated
- Fenfluramine + Selegiline Contraindicated
- Fenfluramine + Tranylcypromine Contraindicated
- Almotriptan + Fenfluramine Major
Frequently asked questions
Can I take Fenfluramine with Meperidine?
MediHelp rates the interaction as major. Fenfluramine and Meperidine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Both drugs raise serotonergic activity, so combined use may precipitate serotonin syndrome with agitation, hyperthermia, clonus and autonomic instability. Fenfluramine's labeling warns of serotonin syndrome with serotonergic drugs, and meperidine is among the opioids implicated. Sedation may also be additive.
How serious is the interaction between Fenfluramine and Meperidine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination and choose a non-serotonergic opioid such as morphine. If used, monitor for serotonin toxicity and stop both drugs if it occurs.
What other medicines interact with Meperidine?
MediHelp also lists interactions of Meperidine with, for example, Alvimopan, Isocarboxazid, Methylene blue. The full list is on the Meperidine page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
