Signs and symptoms of serotonin toxicity
Tremor
Hyperreflexia (increased reflexes)*
Clonus (rhythmic muscle spasms that can be spontaneous, inducible, or ocular)*
Mydriasis (dilated pupils)
Diaphoresis (sweating)
Tachycardia (increased heart rate)
Tachypnea (increased breathing rate)
Agitation
Excitement
Restlessness
Confusion
Delirium
Data from Dunkley et al,1 Boyer and Shannon,2 Ables and Nagubilli,12 and Isbister et al.13
↵* Hyperreflexia and clonus are often worse in the legs than in the arms.