MAOIs + Tramadol/Meperidine
MAOIs + Opioids (tramadol/meperidine): the short answerCertain opioids — tramadol, meperidine (pethidine), methadone, and tapentadol — can cause fatal serotonin syndrome in people on MAOIs. This interaction has killed people at normal doses; it is one of the strictest contraindications in medicine.
Why it’s dangerous
These particular opioids block serotonin reuptake in addition to their opioid effects. With the serotonin-clearing enzyme disabled by an MAOI, serotonin floods the system — producing serotonin syndrome plus, in some cases, extreme blood-pressure reactions and profound respiratory depression. The reaction can begin within an hour of a single dose.
What happens
- Serotonin syndrome: agitation, high fever, rigid and jerking muscles
- Dangerous blood-pressure swings
- Exaggerated sedation and breathing suppression
- Rapid deterioration — coma and death are documented
Warning signs
- Sweating, tremor, and confusion soon after the opioid dose
- High temperature with stiff muscles or twitching
- Severe headache, pounding heart, or very slow breathing
What to do
- Call emergency services immediately and say the person is on an MAOI
- Give naloxone if breathing is dangerously slow — it helps the opioid side
- Keep the person cool; do not give any further doses
- If you take an MAOI, treat tramadol, meperidine, methadone, tapentadol, and DXM-containing products as off-limits; wear or carry something that says you take an MAOI