Drug interactions
Desvenlafaxine + Fentanyl
Severity: Major
Desvenlafaxine and Fentanyl: 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
Both drugs increase serotonergic neurotransmission, so combining them can precipitate serotonin syndrome. Symptoms include agitation, tremor, clonus, hyperthermia and autonomic instability.
What this interaction means in plain words
Desvenlafaxine and Fentanyl 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.
Desvenlafaxine belongs to Central Nervous System; Fentanyl belongs to Musculoskeletal.
Why it happens
Additive serotonergic effects from SNRI reuptake inhibition and fentanyl serotonergic activity.
What to do
Use only if needed, with the lowest effective doses, and monitor for serotonin syndrome after initiation or dose changes. Discontinue the agents if toxicity develops.
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 Fentanyl
- Alvimopan + Fentanyl Contraindicated
- Fentanyl + Isocarboxazid Contraindicated
- Fentanyl + Olanzapine / samidorphan Contraindicated
- Fentanyl + Phenelzine Contraindicated
- Fentanyl + Tranylcypromine Contraindicated
- Alfentanil + Fentanyl Major
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 Fentanyl?
MediHelp rates the interaction as major. Desvenlafaxine and Fentanyl 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 increase serotonergic neurotransmission, so combining them can precipitate serotonin syndrome. Symptoms include agitation, tremor, clonus, hyperthermia and autonomic instability.
How serious is the interaction between Desvenlafaxine and Fentanyl?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use only if needed, with the lowest effective doses, and monitor for serotonin syndrome after initiation or dose changes. Discontinue the agents if toxicity develops.
What other medicines interact with Fentanyl?
MediHelp also lists interactions of Fentanyl with, for example, Alvimopan, Isocarboxazid, Olanzapine / samidorphan. The full list is on the Fentanyl page.
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