MAOIs + DXM
MAOIs + DXM: the short answerDXM (in cough syrups and robotripping) is a serotonin-releasing drug — combined with an MAOI it can cause serotonin syndrome and death. Anyone on an MAOI must avoid DXM entirely, including ordinary cough medicine.
Why it’s dangerous
Dextromethorphan raises serotonin by blocking its reuptake and promoting its release. With MAO enzymes disabled by an MAOI, serotonin cannot be cleared and rapidly reaches toxic levels. Fatal cases have involved nothing more than therapeutic cough-syrup doses taken by people on MAOIs.
What happens
- Serotonin syndrome: agitation, sweating, high fever, rigid muscles
- Severe nausea, vomiting, and diarrhea
- Blood-pressure spikes and racing heartbeat
- Seizures and coma in severe cases
Warning signs
- Confusion, tremor, and sweating after taking a DXM product
- Fever above ~38.5°C/101°F with stiff or jerking muscles
- Severe headache or pounding heartbeat
What to do
- Call emergency services and say the person takes an MAOI and used DXM
- Do not take any further doses of anything
- On an MAOI? Check every cold/flu product — many contain dextromethorphan
- This applies for about two weeks after stopping an MAOI too