Symptomerne på serotoninsyndrom kan omfatte: ændringer i mentaltilstand (f. eks. agitation, hallucinationer, koma), autonom ustabilitet (f. eks. takykardi, ustabilt blodtryk, hypertermi),
As with other serotonergic agents, serotonin syndrome, a potentially life-threatening condition, may occur with venlafaxine treatment, particularly with concomitant use of other agents, such as MAO- inhibitors, that may affect the serotonergic neurotransmitter systems (see sections 4.3 and 4.5).