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What is Zonisamide
Zonisamide is a sulfonamide anticonvulsant. It is a derivative of a series of compounds known as benzisoxazoles.
The pharmacological profile is similar to that of carbamazepine and phenytoin; however, no comparative double-blind trials have been published.
Zonisamide showed a significant reduction in seizure frequency as compared to placebo.
No less than 28% of patients achieved a >= 50% reduction in seizure frequency during three multicenter, placebo-controlled, double blind, 3-month clinical trials (two in the US, one in Europe).
Zonisamide appears to possess more than one mechanism of action which may make it effective in a broader range of seizures. Central nervous system adverse reactions (e.g., ataxia, psychosis, speech impairment, etc.) are common and can limit the usefulness of the drug in some patients.
Zonisamide is approved for adjunctive treatment of partial seizures in adults 16 years and older with epilepsy.
Although not approved for use in children in the US, the drug is often used ‘off-label’ in children; the drug is approved for use in children in Japan where it has been marketed since 1989. FDA approval for zonisamide was granted in March 2000.
Brand Name
Zonegran
Indications & Dosage
- partial seizures
For use as adjunctive therapy in the treatment of partial seizures
Side Effects
- abdominal pain
- acne vulgaris
- agitation
- agranulocytosis
- alopecia
- amblyopia
- amenorrhea
- anemia
- anhidrosis
- anorexia
- anxiety
- aplastic anemia
- apnea
- arthralgia
- asthenia
- ataxia
- atopic dermatitis
- atrial fibrillation
- azotemia
- bradycardia
- chest pain (unspecified)
- cholangitis
- cholecystitis
- cholelithiasis
- colitis
- confusion
- conjunctivitis
- constipation
- cough
- dehydration
- depression
- diarrhea
- diplopia
- dizziness
- drowsiness
- Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)
- dysarthria
- dysgeusia
- dyskinesia
- dyspepsia
- dysphagia
- dyspnea
- dystonic reaction
- dysuria
- ecchymosis
- edema
- encephalopathy
- esophagitis
- euphoria
- fatigue
- fecal incontinence
- flank pain
- flatulence
- gastritis
- gingival hyperplasia
- gingivitis
- glossitis
- gynecomastia
- hallucinations
- headache
- hearing loss
- heart failure
- heat intolerance
- hematemesis
- hematuria
- hemoptysis
- hepatic necrosis
- hirsutism
- hyperammonemia
- hyperesthesia
- hyperhidrosis
- hyperkinesis
- hyperreflexia
- hypertension
- hyperthermia
- hypertonia
- hypoglycemia
- hyponatremia
- hypotension
- hypotonia
- impotence (erectile dysfunction)
- increased urinary frequency
- influenza
- insomnia
- iritis
- irritability
- jaundice
- leukopenia
- libido decrease
- lupus-like symptoms
- lymphadenopathy
- maculopapular rash
- malaise
- melena
- memory impairment
- menorrhagia
- metabolic acidosis
- muscle cramps
- myalgia
- myasthenia
- myoclonia
- myopia
- nausea
- nephrolithiasis
- neuritis
- nocturia
- nystagmus
- ocular hypertension
- oligohidrosis
- oral ulceration
- osteomalacia
- palpitations
- pancreatitis
- paresthesias
- parosmia
- peptic ulcer
- peripheral edema
- peripheral neuropathy
- petechiae
- pharyngitis
- photophobia
- polyuria
- proteinuria
- pruritus
- psychosis
- pulmonary embolism
- rash
- renal failure (unspecified)
- rhabdomyolysis
- rhinitis
- seizures
- sinus tachycardia
- Stevens-Johnson syndrome
- stomatitis
- stroke
- suicidal ideation
- syncope
- teratogenesis
- thrombocytopenia
- tinnitus
- toxic epidermal necrolysis
- tremor
- urinary incontinence
- urinary retention
- urinary urgency
- urticaria
- vertigo
- vomiting
- weight gain
- weight loss
- xerosis
- xerostomia
Monitoring Parameters
- serum bicarbonate
- serum creatinine/BUN
Contraindications
- abrupt discontinuation
- ambient temperature increase
- anticholinergic medications
- breast-feeding
- children
- depression
- diarrhea
- driving or operating machinery
- geriatric
- hepatic disease
- infants
- metabolic acidosis
- mitochondrial disease
- neonates
- pregnancy
- pulmonary disease
- renal disease
- renal failure
- renal impairment
- status epilepticus
- suicidal ideation
- sulfonamide hypersensitivity
Interactions
- Acetaminophen; Butalbital
- Acetaminophen; Butalbital; Caffeine
- Acetaminophen; Butalbital; Caffeine; Codeine
- Acetazolamide
- Afatinib
- Aliskiren
- Aliskiren; Amlodipine
- Aliskiren; Amlodipine; Hydrochlorothiazide, HCTZ
- Aliskiren; Hydrochlorothiazide, HCTZ
- Aliskiren; Valsartan
- Alogliptin; Metformin
- Alprazolam
- Amitriptyline
- Amitriptyline; Chlordiazepoxide
- Amlodipine; Atorvastatin
- Amobarbital
- Amoxicillin; Clarithromycin; Lansoprazole
- Amoxicillin; Clarithromycin; Omeprazole
- Amphetamines
- Anticholinergics
- Apalutamide
- Apixaban
- Aprepitant, Fosaprepitant
- Aripiprazole
- Asenapine
- Asparaginase Erwinia chrysanthemi
- Aspirin, ASA; Butalbital; Caffeine
- Aspirin, ASA; Butalbital; Caffeine; Codeine
- Atorvastatin
- Atorvastatin; Ezetimibe
- Atropine
- Atropine; Benzoic Acid; Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate
- Atropine; Difenoxin
- Atropine; Diphenoxylate
- Atropine; Edrophonium
- Atropine; Hyoscyamine; Phenobarbital; Scopolamine
- atypical antipsychotic
- Barbiturates
- Belladonna Alkaloids; Ergotamine; Phenobarbital
- Belladonna; Opium
- Benzoic Acid; Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate
- Benztropine
- Betrixaban
- Boceprevir
- Bosentan
- Brexpiprazole
- Budesonide
- Budesonide; Formoterol
- Bupropion
- Bupropion; Naltrexone
- Butabarbital
- Canagliflozin; Metformin
- Carbamazepine
- Carbonic anhydrase inhibitors
- Cariprazine
- Carvedilol
- Chlordiazepoxide; Clidinium
- Chlorpromazine
- Clarithromycin
- Clomipramine
- Clozapine
- Cobimetinib
- Codeine; Phenylephrine; Promethazine
- Codeine; Promethazine
- Colchicine
- Colchicine; Probenecid
- Colesevelam
- Cyclosporine
- Dabigatran
- Dapagliflozin; Metformin
- Dapagliflozin; Saxagliptin
- Dasabuvir; Ombitasvir; Paritaprevir; Ritonavir
- Desipramine
- Dexamethasone
- Dextromethorphan; Promethazine
- Dextromethorphan; Quinidine
- Dichlorphenamide
- Dicyclomine
- Digoxin
- Docetaxel
- Doravirine; Lamivudine; Tenofovir disoproxil fumarate
- Doxepin
- Doxorubicin
- Dronedarone
- Drospirenone; Ethinyl Estradiol
- Drospirenone; Ethinyl Estradiol; Levomefolate
- Efavirenz
- Efavirenz; Emtricitabine; Tenofovir
- Efavirenz; Lamivudine; Tenofovir Disoproxil Fumarate
- Elbasvir; Grazoprevir
- Eletriptan
- Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Disoproxil Fumarate
- Empagliflozin; Linagliptin; Metformin
- Empagliflozin; Metformin
- Emtricitabine; Rilpivirine; Tenofovir disoproxil fumarate
- Emtricitabine; Tenofovir disoproxil fumarate
- Enzalutamide
- Ertugliflozin; Metformin
- Erythromycin
- Erythromycin; Sulfisoxazole
- Ethinyl Estradiol
- Ethinyl Estradiol; Desogestrel
- Ethinyl Estradiol; Ethynodiol Diacetate
- Ethinyl Estradiol; Etonogestrel
- Ethinyl Estradiol; Levonorgestrel
- Ethinyl Estradiol; Levonorgestrel; Ferrous bisglycinate
- Ethinyl Estradiol; Levonorgestrel; Folic Acid; Levomefolate
- Ethinyl Estradiol; Norelgestromin
- Ethinyl Estradiol; Norethindrone
- Ethinyl Estradiol; Norethindrone Acetate
- Ethinyl Estradiol; Norethindrone Acetate; Ferrous fumarate
- Ethinyl Estradiol; Norethindrone; Ferrous fumarate
- Ethinyl Estradiol; Norgestimate
- Ethinyl Estradiol; Norgestrel
- Ethotoin
- Felbamate
- Flavoxate
- Fluoxetine; Olanzapine
- Fluphenazine
- Fosamprenavir
- Fosphenytoin
- Glecaprevir; Pibrentasvir
- Glipizide; Metformin
- Glyburide
- Glyburide; Metformin
- Glycopyrrolate
- Glycopyrrolate; Formoterol
- Haloperidol
- Homatropine; Hydrocodone
- Hydroxychloroquine
- Hyoscyamine
- Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate; Sodium Biphosphate
- Idelalisib
- Iloperidone
- Imipramine
- Indacaterol; Glycopyrrolate
- Indinavir
- Isavuconazonium
- Isocarboxazid
- Isoniazid, INH; Pyrazinamide, PZA; Rifampin
- Isoniazid, INH; Rifampin
- Itraconazole
- L-Asparaginase Escherichia coli
- Lacosamide
- Lamivudine; Tenofovir Disoproxil Fumarate
- Lapatinib
- Ledipasvir; Sofosbuvir
- Lefamulin
- Linagliptin; Metformin
- Loperamide
- Loperamide; Simethicone
- Lopinavir; Ritonavir
- Loxapine
- Lumacaftor; Ivacaftor
- Lumacaftor; Ivacaftor
- Lumateperone
- Lurasidone
- Maprotiline
- Maraviroc
- Mefloquine
- Mepenzolate
- Meperidine; Promethazine
- Mephobarbital
- Mesoridazine
- Metformin
- Metformin; Pioglitazone
- Metformin; Repaglinide
- Metformin; Rosiglitazone
- Metformin; Saxagliptin
- Metformin; Sitagliptin
- Methadone
- Methazolamide
- Methenamine; Sodium Acid Phosphate; Methylene Blue; Hyoscyamine
- Methohexital
- Methscopolamine
- Mitomycin
- Mitotane
- Molindone
- Monoamine oxidase inhibitors
- Morphine
- Morphine; Naltrexone
- Nelfinavir
- Nevirapine
- Nortriptyline
- Olanzapine
- Ombitasvir; Paritaprevir; Ritonavir
- Omeprazole; Amoxicillin; Rifabutin
- Ondansetron
- Oritavancin
- Oxybutynin
- Paclitaxel
- Paliperidone
- Panobinostat
- Pazopanib
- Pegaspargase
- Pemoline
- Pentobarbital
- Perphenazine
- Perphenazine; Amitriptyline
- Phenelzine
- Phenobarbital
- Phenothiazines
- Phentermine; Topiramate
- Phenylephrine; Promethazine
- Phenytoin
- Pimozide
- Posaconazole
- Primidone
- Prochlorperazine
- Promethazine
- Propantheline
- Protriptyline
- Quetiapine
- Quinidine
- Quinine
- Rabeprazole
- Ranolazine
- Rifabutin
- Rifampin
- Rifapentine
- Rimegepant
- Riociguat
- Risperidone
- Ritonavir
- Rivaroxaban
- Romidepsin
- Rufinamide
- Saquinavir
- Saxagliptin
- Scopolamine
- Secobarbital
- Segesterone Acetate; Ethinyl Estradiol
- Selegiline
- Selexipag
- Simeprevir
- Sirolimus
- Sofosbuvir
- Sofosbuvir; Velpatasvir
- Sofosbuvir; Velpatasvir; Voxilaprevir
- St. John’s Wort, Hypericum perforatum
- Talazoparib
- Telaprevir
- Telithromycin
- Telotristat Ethyl
- Temsirolimus
- Teniposide
- Tenofovir Alafenamide
- Tenofovir, PMPA
- Testosterone
- Thiethylperazine
- Thiopental
- Thioridazine
- Thiothixene
- Ticagrelor
- Tipranavir
- Tolvaptan
- Topiramate
- Topotecan
- Trandolapril; Verapamil
- Tranylcypromine
- Tricyclic antidepressants
- Trifluoperazine
- Trihexyphenidyl
- Trimipramine
- Trospium
- Ubrogepant
- Valproic Acid, Divalproex Sodium
- Vemurafenib
- Venetoclax
- Verapamil
- Zafirlukast
- Zileuton
- Ziprasidone
