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, diarrhoea).