“…21 Agents capable of increasing serotonin levels and precipitating serotonin syndrome include antidepressants (SSRIs, SNRIs, TCAs, MAOIs) alone or in combination with other proserotonergic medications such as phenylpiperidine opioids (particularly meperidine, but potentially fentanyl and its derivatives) tramadol, dextromethorphan, ondansetron, metoclopramide, methylene blue, erythromycin, metronidazole, the antimigraine medications ''triptans,'' selegiline, the second generation (atypical) antipsychotics (eg, aripiprazole, clozapine, olanzapine, quetiapine, risperidone) St. John's wort, and 3,4-methylenedioxy-methamphetamine (MDMA or ecstasy). 1,3,9,12,[14][15][16]20,[22][23][24] It should be noted that serotonin antagonists, such as the 5-HT 3 antagonist antiemetics, may inhibit binding of serotonin to this subset of receptors thus increasing availability of serotonin to other serotonin receptors. In this way, serotonin syndrome may be precipitated.…”