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    DEA Class;  Rx

    Common Brand Names; Zarontin

    • Anticonvulsants, Succinimide

    Oral succinimide anticonvulsant
    Used for the treatment of absence seizures
    May increase the frequency of grand mal seizures when used alone in mixed types of epilepsy

    Indicated for the treatment of absence seizures.



    • Dizziness

    • Headache

    • Somnolence

    • Anorexia

    • Diarrhea

    • GI upset

    • Nausea

    • Vomiting

    Less Common

    • Ataxia, confusion, drowsiness, sleep disturbance

    • Gum hypertrophy, hiccoughs, swelling of tongue

    • Blood dyscrasias including aplastic anemia

    • Allergic reaction

    • Urticaria

    • Pruritic erythematous rashes

    • Blurred vision, myopia


    • Psychosis

    • Seizure

    • Suicidal thoughts and behavior

    • Stevens-Johnson syndrome

    • Systemic lupus erythematosus

    • Hirsutism

    Do not discontinue rapidly; proceed slowly when increasing or decreasing dosage, as well as when adding or eliminating other medications; abrupt withdrawal of anticonvulsant medication may precipitate absence (petit mal) status

    When used alone in mixed types of epilepsy, therapy may increase frequency of grand mal seizures in some patients

    Blood dyscrasias may occur; perform periodic blood counts; should signs and/or symptoms of infection (e.g., sore throat, fever) develop, consider blood counts

    Cases of systemic lupus erythematosus reported with use of drug; the physician should be alert to this possibility

    Serious dermatologic reactions reported including Stevens-Johnson syndrome (SJS); onset usually within 28 days, but can occur later; discontinue therapy at first sign of rash, unless rash is clearly not drug-related; if signs or symptoms suggest SJS, use of this drug should not be resumed; consider alternative therapy

    Drug reaction with Eosinophilia and Systemic Symptoms (DRESS), also known as multi organ hypersensitivity, reported; some fatal or life-threatening; early manifestations of hypersensitivity (e.g. fever, lymphadenopathy) may be present even though rash is not evident; if such signs or symptoms appear, the patient should be evaluated immediately and therapy discontinued if an alternative etiology for the signs or symptoms cannot be established

    Drug crosses placenta; reports suggest an association between use of anticonvulsant drugs by women with epilepsy and elevated incidence of birth defects in children born to these women

    The drug is excreted in human breast milk; because effects of ethosuximide on nursing infant are unknown, use caution when administering to a nursing mother; the drug should be used in nursing mothers only if the benefits clearly outweigh the risks


    1.5 g/day PO.


    1.5 g/day PO.


    1.5 g/day PO.


    3 to 11 years: 1.5 g/day PO.
    1 to 2 years: Safety and efficacy have not been established.


    Safety and efficacy have not been established.


    Safety and efficacy have not been established.



    • 250mg


    • 250mg/5mL