Adverse Drug Reactions

Zonisamide has been administered to over 1,200 patients in clinical studies, more than 400 of whom received Zonisamide for at least 1 year. The most common adverse reactions in controlled adjunctive therapy studies were somnolence, dizziness and anorexia. Adverse reactions associated with Zonisamide obtained from clinical studies and post-marketing surveillance are tabulated below*.

System Organ Class Very Common
(0.1 – 1%)
Very Rare
(<0.001 %)
Blood and lymphatic system Ecchymosis Agranulocytosis
Aplastic anemia
Immune system disorders Hypersensitivity
Metabolism & Nutrition disorders Anorexia
Psychiatric disorders Affect lability, agitation,
anxiety, depression, insomnia, irritability, psychotic disorder
Suicide attempt
Nervous system disorders Dizziness, somnolence Ataxia, bradyphrenia, confusion, convulsion, disturbance in attention, memory impairment,
nystagmus, paresthesia, speech disorder, tremor
Status epilepticus
Eye disorders Diplopia
Gastrointestinal disorders Abdominal pain, constipation, diarrhea, dyspepsia, nausea Pancreatitis
Skin & subcutaneous tissue disorders Rash Anhidrosis, erythema multiforme, Stevens- Johnson syndrome, Drug
reaction with eosinophilia and systemic symptoms
Renal and urinary disorders Nephrolithiasis Renal failure
General disorders and administration site conditions Fatigue, influenza like
Hyperthermia, sudden unexplained death in epilepsy
Investigations Decreased bicarbonate Weight decreased Increase in alanine aminotransferase, aspartate aminotransferase, blood
creatine phosphokinase,
blood creatinine, blood urea
* The basic rule used in creating the table was to include in the tabulation for the very common & common adverse reactions those adverse reactions experienced by >2% and more by Zonisamide treated patients than the placebo in the double blind studies. The one exception is Nephrolithiasis which is based on the reported
incidence in the open label studies because it appears to increase in frequency with increased duration of therapy. The other events are based on post marketing reports.

Reporting of suspected adverse drug reactions
Please contact:
HI-Eisai Pharmaceutical, Inc.
+63 2 88875837 / +63 2 88875160 / +63 9088672236
Or Report to FDA Philippines: