Race: No racial predilection is known.
TreatmentMedical Care: Treatment involves antiepileptic drugs (AEDs). Once the proper diagnosis (ie, of the specific epilepsy syndrome) is made, the likelihood of other coexistent seizure types, such as myoclonic or tonic-clonic, should be considered and an appropriate medication selected.Activity: Physical activity should not be restricted any more than necessary. Activities in which a seizure might pose a threat, such as swimming or rock climbing, may be allowed with appropriate supervision. A child with epilepsy should not be unnecessarily handicapped. Patients with uncontrolled absence seizures should not be allowed to drive. The situation may be unclear when the patient's clinical seizures are controlled but the EEG still shows some spike-wave activity.
Medication
Most AEDs are relatively toxic. Patients often take them every day, usually several times a day, for many years. Therefore, the decision to start such a medication is difficult. Once a patient has more than one unprovoked seizure, the decision to start medication is straightforward; EEG studies can help to confirm this decision. Drug Category: Antiepileptics -- If the patient has only absence seizures, then ETX (Zarontin) is an appropriate medication. This may be the case for patients with CAE. ETX also may be used in conjunction with an anticonvulsive AED, such as phenytoin (PHT, Dilantin) for patients at risk of tonic-clonic seizures in whom VPA is contraindicated.
Drug Name | ETX (Zarontin) -- Succinimide AED effective only against absence seizures. No effect on GTC, myoclonic, atonic, or partial seizures. Mechanism of action based on reducing current in T-type calcium channels on thalamic neurons. Spike-and-wave pattern during petit mal seizures thought to be initiated in thalamocortical relays by activation of these channels. Available in large 250-my capsules, which may be difficult for some children to swallow, and as syrup (250 mg/5 mL). |
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Adult Dose | 250 mg PO bid; increase by 250-mg increments q4-7d until seizures controlled or maximum daily dose reached; not to exceed 1.5 g/d |
Pediatric Dose | <6> >6 years: Administer as in adults Maintenance dose: 15-40 mg/kg/d PO divided bid |
Contraindications | Documented hypersensitivity; blood dyscrasias; renal or hepatic disease |
Interactions | Generally minimal; enzyme-inducing drugs (eg, PHT, carbamazepine, phenobarbital) may lower levels by 15-25%; valproic acid may elevate levels; has weak enzyme-inhibiting effect, usually insignificant with respect to metabolism of other drugs |
Pregnancy | C - Safety for use during pregnancy has not been established. |
Precautions | Blood dyscrasias may occur and may be fatal (monitor CBC); caution in hepatic or renal disease; abrupt withdrawal may precipitate absence status |
Drug Name | Valproic acid (Depakene, Depacon, Depakote, Depakote ER) -- DOC for patients who have absence and GTC and/or myoclonic seizures; aliphatic compound, carboxylic acid. Discovery was serendipitous; used as solvent potential AEDs, and all test compounds seemed to work. Mechanism of action not known but believed related to ability to increase brain GABA. May inhibit rapid opening of sodium channels and block T-type calcium channels. VPA (Depakene) available as syrup (250 mg/5 mL), 250- or 500-mg capsules, and IV preparation (100 mg/5 mL; Depacon). Divalproex sodium (Depakote) available as 250- or 500-mg tab and 125-mg capsule (Depakote Sprinkles), which can be opened and mixed with food. Syrup rapidly absorbed through stomach and produces gastric irritation. Rapidly produces high serum levels and may cause peak-dose toxicity. Must be given in 3-4 divided doses. Other oral preparations absorbed more slowly from GI tract and better tolerated. Because of slower absorption, some patients who have achieved control may be treated with bid dosing. Highly protein bound; protein binding is level dependent. At 40 mg/mL, 90% bound, but at 130 mg/mL, 80% bound. Therefore, as total level increases from 40 to 130 mg/mL, free level increases from 4 to 26 mg/mL. Therapeutic range originally 50-100 mg/mL; patients with hard-to-control seizures may require higher level. Depakote ER is extended-release product intended for once-a-day oral administration. When converting from Depakote to Depakote ER, dose 8-20% higher than total daily dose of Depakote is needed. IV Depacon may be given as maintenance therapy; amount mixed with at least 50 mL of compatible diluent and infused at rate not >20 mg/kg/min over at least 60 min; research ongoing concerning IV loading at more rapid rates. |
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Adult Dose | 10-15 mg/kg/d PO initially; increase by 5-10 mg/kg/d weekly until seizures controlled or adverse effects develop; not to exceed 60 mg/kg/d divided tid/qid |
Pediatric Dose | 15 mg/kg/d PO initial dose, increasing by 5-10 mg/kg/d weekly until seizures controlled or adverse effects develop; maximum recommended dosage 60 mg/kg/d divided tid/qid; for select patients with complete control, bid dosing may be tried |
Contraindications | Documented hypersensitivity; hepatic disease or dysfunction; because of teratogenicity, first trimester of pregnancy and in women of childbearing age who are not on adequate birth control, unless it is clearly the most effective drug for a woman planning pregnancy and aware of risks |
Interactions | Cimetidine, salicylates, felbamate, and erythromycin may increase toxicity; rifampin, phenytoin, phenobarbital, and carbamazepine may significantly reduce levels; in children, salicylates decrease protein binding and metabolism; carbamazepine may result in variable changes of carbamazepine concentrations with possible toxicity or loss of seizure control; may increase diazepam and ETX toxicity (monitor closely); may increase phenobarbital and phenytoin levels; may displace warfarin from protein-binding sites (monitor coagulation tests) and can displace phenytoin, resulting in transient increase in free levels; may increase zidovudine levels in HIV-seropositive patients |
Pregnancy | D - Unsafe in pregnancy |
Precautions | Hepatic dysfunction may occur (more common in children taking multiple AEDs) during first 6 mo of therapy, and may be fatal; assess liver function test (LFT) results before therapy and at frequent intervals during first 6 mo; clinical symptoms (loss of seizure control, malaise, weakness, lethargy, facial edema, anorexia, vomiting) may precede LFT abnormalities; hyperammonemia reported and may be occur despite normal LFTs; may cause lethargy or coma; when asymptomatic elevations of ammonia are present, more frequent monitoring indicated; carnitine supplementation may be beneficial in addition to platelet dysfunction, thrombocytopenia may occur and associated with high doses; pancreatitis may occur, even after several years of therapy; perform appropriate tests in patients with malabsorption, abdominal pain, or other GI symptoms; spina bifida in 1-2% of children born to women taking VPA during first 12 wk of pregnancy; women planning to become pregnant should take folic acid 1-5 mg/d, and consider crossing over to ETX before conception; for women with have GTC seizures, ETX and anticonvulsant AED can be used |