Drug interactions
Dextroamphetamine + Fenfluramine
Severity: Major
Dextroamphetamine and Fenfluramine: 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 serotonin and catecholamine activity, so combining them raises the risk of serotonin syndrome and of additive blood pressure and heart rate increases. Fenfluramine is also associated with valvular heart disease and pulmonary hypertension, which adds concern with other sympathomimetics.
What this interaction means in plain words
Dextroamphetamine and Fenfluramine 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.
Dextroamphetamine belongs to Central Nervous System; Fenfluramine belongs to Central Nervous System.
Why it happens
Additive serotonergic and sympathomimetic effects through monoamine release.
What to do
Avoid combining where possible and use only with close monitoring for serotonin toxicity, blood pressure and heart rate. Continue echocardiographic surveillance as required for fenfluramine.
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 Dextroamphetamine
- Dextroamphetamine + Isocarboxazid Contraindicated
- Dextroamphetamine + Linezolid Contraindicated
- Dextroamphetamine + Methylene blue Contraindicated
- Dextroamphetamine + Phenelzine Contraindicated
- Dextroamphetamine + Rasagiline Contraindicated
- Dextroamphetamine + Safinamide 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 Dextroamphetamine with Fenfluramine?
MediHelp rates the interaction as major. Dextroamphetamine and Fenfluramine 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 serotonin and catecholamine activity, so combining them raises the risk of serotonin syndrome and of additive blood pressure and heart rate increases. Fenfluramine is also associated with valvular heart disease and pulmonary hypertension, which adds concern with other sympathomimetics.
How serious is the interaction between Dextroamphetamine and Fenfluramine?
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 combining where possible and use only with close monitoring for serotonin toxicity, blood pressure and heart rate. Continue echocardiographic surveillance as required for fenfluramine.
What other medicines interact with Dextroamphetamine?
MediHelp also lists interactions of Dextroamphetamine with, for example, Isocarboxazid, Linezolid, Methylene blue. The full list is on the Dextroamphetamine page.
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