Drug interactions
Dextroamphetamine transdermal + Dextromethorphan
Severity: Major
Dextroamphetamine transdermal 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
Both drugs enhance serotonergic neurotransmission, and amphetamines release serotonin in addition to catecholamines. Combined use increases the risk of serotonin syndrome, with agitation, tremor, hyperthermia, clonus and autonomic instability.
What this interaction means in plain words
Dextroamphetamine transdermal 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 from amphetamine-induced serotonin release and dextromethorphan serotonin reuptake inhibition.
What to do
Avoid combining where possible, and use lower starting doses if needed with monitoring for serotonin toxicity at initiation and dose increases. Stop the serotonergic agents and treat if serotonin syndrome 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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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 Dextroamphetamine transdermal with Dextromethorphan?
MediHelp rates the interaction as major. Dextroamphetamine transdermal 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. Both drugs enhance serotonergic neurotransmission, and amphetamines release serotonin in addition to catecholamines. Combined use increases the risk of serotonin syndrome, with agitation, tremor, hyperthermia, clonus and autonomic instability.
How serious is the interaction between Dextroamphetamine transdermal 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 combining where possible, and use lower starting doses if needed with monitoring for serotonin toxicity at initiation and dose increases. Stop the serotonergic agents and treat if serotonin syndrome develops.
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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