Drug interactions
Dexfenfluramine + Dextromethorphan
Severity: Major
Dexfenfluramine and Dextromethorphan: 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
Dexfenfluramine releases serotonin and blocks its reuptake, and dextromethorphan adds serotonergic activity. The combination may precipitate serotonin syndrome.
What this interaction means in plain words
Dexfenfluramine and Dextromethorphan 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.
Why it happens
Additive serotonergic effects via serotonin release and reuptake inhibition.
What to do
Avoid the combination; if it cannot be avoided, monitor for neuromuscular excitability, hyperthermia and autonomic instability.
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?
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Other interactions of Dextromethorphan
- Dextromethorphan + Isocarboxazid Contraindicated
- Dextromethorphan + Linezolid Contraindicated
- Dextromethorphan + Phenelzine Contraindicated
- Dextromethorphan + Rasagiline Contraindicated
- Dextromethorphan + Safinamide Contraindicated
- Dextromethorphan + Selegiline Contraindicated
Frequently asked questions
Can I take Dexfenfluramine with Dextromethorphan?
MediHelp rates the interaction as major. Dexfenfluramine and Dextromethorphan 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. Dexfenfluramine releases serotonin and blocks its reuptake, and dextromethorphan adds serotonergic activity. The combination may precipitate serotonin syndrome.
How serious is the interaction between Dexfenfluramine and Dextromethorphan?
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; if it cannot be avoided, monitor for neuromuscular excitability, hyperthermia and autonomic instability.
What other medicines interact with Dextromethorphan?
MediHelp also lists interactions of Dextromethorphan with, for example, Isocarboxazid, Linezolid, Phenelzine. The full list is on the Dextromethorphan page.
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