Table 1.

Agents associated with an increased risk of serotonin syndrome.

Monoaminoxidase (MAO) inhibition

MAOI antidepressants Linezolid Methylene blue MAO B inhibitors

Serotonin-reuptake inhibition

SSRIs SNRIs antidepressants or other SNRI agents such as atomoxetine or sibutramine TCAs Bupropion (indirect effect) Some opioids such as tramadol, pethidine (meperidine), pentazocine or dextromethorphan Metoclopramide Setrones Valproate Carbamazepine MDMA (‘Ecstasy’)*

Serotonin release

Amphetamines and amphetamine derivatives including central stimulants and fenfluramine or recreational stimulants Levodopa, carbidopa–levodopa (indirect effect)

Other/unspecified mechanisms leading to increased serotonin activity

Fentanyl Lithium Buspirone Ergotamine LSD

Complementary medicines/dietary supplements with serotonergic activity

Tryptophan Panax ginseng St John’s wort (Hypericum perforatum) SAMe

Unclear/debated whether associated with increased risk

Triptans Mirtazapine 5HT2-blocking antipsychotics

^*Also promotes serotonin release.

5HT, 5-hydroxytryptamine; LSD, lysergic acid diethylamide; MAOI, monoaminoxidase inhibitors; MDMA, 3,4-methylenedioxymethamphetamine; SNRI, serotonin–noradrenaline-reuptake inhibitor; SSRI, selective serotonin-reuptake inhibitor; TCA, tricyclic antidepressant.