Zonisamidum

Description
Medication for epilepsy, sulfonamides.
Indications
Treatment in adults with epilepsy, presenting with partial seizures with secondary generalization or without, as an adjunctive therapy.
Contraindications
Hypersensitivity to the active substance, any excipient, or sulfonamides.
Dosage
For adults. Oral administration. Initially 50 mg per day (in 2 doses), after 1 week can be increased to 100 mg and then every 1 week (every 2 weeks when not taking CYP3A4 inducers) – not exceeding 100 mg each time; maintenance daily dose – up to 300-500 mg. Increase the dose every 2 weeks.
Common side effects: anorexia; agitation, irritability, confusion, depression; ataxia, dizziness, memory impairment, drowsiness; diplopia; decreased bicarbonate concentration.
Common: ecchymosis; increased sensitivity; affective lability, anxiety, insomnia, mental disorders, bradyphrenia, attention disorder, nystagmus, paresthesia, speech disorder, tremor; abdominal pain, constipation, diarrhea, dyspepsia, nausea; rash; nephrolithiasis; fatigue, flu-like symptoms, fever; weight loss.
Uncommon: pneumonia, urinary tract infection; hypokalemia; anger, aggression, suicidal thoughts, suicide attempt; seizures; vomiting; cholecystitis, cholelithiasis; urinary stones.
Very rare: agranulocytosis, aplastic anemia, leukocytosis, leukopenia, lymphadenopathy, pancytopenia, thrombocytopenia; drug-induced hypersensitivity syndrome; drug-induced rash with eosinophilia and systemic symptoms; metabolic acidosis, renal tubular acidosis; hallucinations; amnesia, coma, status epilepticus, myasthenia syndrome, malignant neuroleptic syndrome, epileptic state; dyspnea, aspiration pneumonia, respiratory disorder; pancreatitis; liver damage; anhidrosis, multiform erythema, itching, Stevens-Johnson syndrome, toxic epidermal necrolysis; rhabdomyolysis; hydronephrosis, IFN, urinary changes; increased creatine kinase, creatinine, salicylate concentration, altered liver function tests; heat stroke.
Pregnancy
Do not use except in clearly necessary cases.
Breastfeeding
Do not breastfeed (can only breastfeed 1 month after the last dose).
Warnings
Not recommended in severe renal dysfunction. Use with caution in IFN, risk factors for kidney stones, mild or moderate renal dysfunction, risk factors for acidosis, increased risk of metabolic acidosis-related disorders (check bicarbonate concentration), as well as <40 kg weight and elderly patients. Use with caution in combination with carbonic anhydrase inhibitors and anticholinergic drugs. Ensure adequate hydration and avoid heat. Monitor for suicidal thoughts and signs of suicidal behavior. If pancreatitis is suspected, investigate pancreatic lipase and amylase concentrations. In case of severe muscle pain and/or significant weakness, investigate creatine kinase and aldolase concentrations (if elevated for unknown reasons, consider discontinuing use). In addition, consider discontinuing use if a rash of unknown cause appears (possible Stevens-Johnson syndrome) or pancreatitis of unknown cause, in case of significant unexplained weight loss, clinically significant increase in creatinine concentration. Gradually discontinue use.

Source | Drug Guide | Lithuanian University of Health Sciences | Institute of Physiology and Pharmacology | Doctor of Medical Sciences Rimas Jankūnas, Doctor of Medical Sciences Arvydas Milašius | Clinic of Internal Diseases | Doctor of Medical Sciences Palmira Leišytė