Symptomerne ved overdosering har inkluderet kvalme, opkastning, kramper, kredsløbsforstyrrelser rangerende fra asymptomatiske arytmier til hjertestop, pulmonal dysfunktion samt ændret CNS- status rangerende fra irritation til koma.
Symptoms of overdose have included nausea, vomiting, seizures, cardiovascular dysfunction ranging from asymptomatic arrhythmias to cardiac arrest, pulmonary dysfunction, and signs of altered CNS status ranging from excitation to coma.