Serotonin syndromeThe development of a potentially life-threatening serotonin syndrome (also more recently classified as "serotonin toxicity")[35] may occur with venlafaxine treatment, particularly with concomitant use of serotonergic drugs (including but not limited to SSRI and SNRI)s, many hallucinogens such as tryptamines and phenethylamines(LSD/LSA, DMT, MDMA, MDPV, mescaline for example), dextromethorphan(DXM)/dextrorphan(DXO), ********, tapentadol, meperidine/pethidine and triptans) and with drugs that impair metabolism of serotonin (including MAOIs). Serotonin syndrome symptoms may include mental status changes (e.g., agitation, hallucinations, coma), autonomic instability (e.g., tachycardia, labile blood pressure, hyperthermia), neuromuscular aberrations (e.g., hyperreflexia, incoordination) and/or gastrointestinal symptoms (e.g., nausea, vomiting, diarrhea). Venlafaxine-induced serotonin syndrome has also been reported when venlafaxine has been taken in isolation in overdose.[36] An abortive serotonin syndrome state, in which some but not all of the symptoms of the full serotonin syndrome are present, has been reported with venlafaxine at mid-range dosages (150 mg per day)[37] A case of a patient with serotonin syndrome induced by low-dose venlafaxine (37.5 mg per day) has also been reported.[38]