Drug interactions
Desvenlafaxine + Dexfenfluramine
Severity: Major
Desvenlafaxine and Dexfenfluramine: major interaction.
Last updated Sources: US FDA label
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, so it can cause serotonin syndrome when combined with desvenlafaxine. The drug has been withdrawn in most markets due to valvular heart disease.
What this interaction means in plain words
Desvenlafaxine and Dexfenfluramine 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 through serotonin release and reuptake inhibition.
What to do
Avoid the combination. If exposure occurs, monitor for serotonin syndrome and stop one or both agents if symptoms appear.
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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References
Other interactions of Desvenlafaxine
- Desvenlafaxine + Isocarboxazid Contraindicated
- Desvenlafaxine + Methylene blue Contraindicated
- Desvenlafaxine + Phenelzine Contraindicated
- Desvenlafaxine + Rasagiline Contraindicated
- Desvenlafaxine + Safinamide Contraindicated
- Desvenlafaxine + Selegiline Contraindicated
Frequently asked questions
Can I take Desvenlafaxine with Dexfenfluramine?
MediHelp rates the interaction as major. Desvenlafaxine and Dexfenfluramine 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, so it can cause serotonin syndrome when combined with desvenlafaxine. The drug has been withdrawn in most markets due to valvular heart disease.
How serious is the interaction between Desvenlafaxine and Dexfenfluramine?
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 exposure occurs, monitor for serotonin syndrome and stop one or both agents if symptoms appear.
What other medicines interact with Desvenlafaxine?
MediHelp also lists interactions of Desvenlafaxine with, for example, Isocarboxazid, Methylene blue, Phenelzine. The full list is on the Desvenlafaxine page.
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