Symptoms: In some cases, overdoses were asymptomatic. In other cases, the overdose was followed by symptoms such as somnolence, nausea, gastritis, nystagmus, myoclonus, coma, bradycardia, reduced renal function, hypotension and respiratory depression.
Treatment: No specific antidotes for Zonisamide overdose are available. Emptying the stomach by gastric lavage or by induction of emesis may be indicated with the usual precautions to protect the airway. General supportive care is indicated, including frequent monitoring of vital signs and close observation. Hemodialysis reduced plasma concentrations of zonisamide in patients with reduced renal function, and may be considered as treatment of overdose if clinically indicated.