Is 5-HTP (5-Hydroxytryptophan) Safe with Meperidine (Pethidine)?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
Do not use 5-HTP in patients receiving meperidine. Advise patients to disclose all supplement use before any opioid is prescribed. If concurrent use is identified, discontinue 5-HTP and monitor for serotonin syndrome symptoms (agitation, tremor, hyperthermia, diaphoresis).
Why this interaction occurs
Meperidine has serotonin reuptake inhibiting properties in addition to its opioid activity. Combined with 5-HTP, a serotonin precursor, it can precipitate serotonin syndrome through excess serotonergic stimulation. Animal studies confirm meperidine induces serotonin syndrome-like behaviors, with exaggerated responses in SERT-deficient conditions.
Evidence
Evidence level: moderate.
Data source
PubMed - PMID 19275775
Reported safety data
The FDA’s adverse event reporting system (FAERS) has received 5,542 reports mentioning Meperidine (Pethidine). This reflects reported cases involving the medication in general — not confirmed causation, and not specific to the Meperidine (Pethidine) + supplement combination on this page.
FAERS reports are voluntary and cannot prove that a drug caused an event. Do not use report counts to assess the safety of this specific drug-supplement pair.
Frequently asked questions
Related interactions
All 5-HTP (5-Hydroxytryptophan) interactions → · All Meperidine (Pethidine) interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.