When used for the appropriate seizure type, antiseizure medications (ASMs) are roughly equivalent in efficacy. In addition to the seizure type, the choice of drug is usually based on factors such as ease of use, spectrum of activity, adverse effects, interactions with other drugs, presence of comorbid conditions, suitability for elderly persons and those with childbearing potential, and cost. Treatment should begin with a single drug, increasing the dosage gradually until seizures are controlled or adverse effects become unacceptable. If seizures persist, expert clinicians generally try at least one and sometimes a second alternative drug as monotherapy before considering use of two drugs at the same time.

The FDA is advising health care professionals not to prescribe valproate sodium (Depacon), valproic acid (Depakene, Stavzor, and generics) or divalproex sodium (Depakote, Depakote ER, and generics) for migraine prevention in pregnant women because a recently published study showed that IQ scores are decreased in children of mothers who took these drugs during pregnancy. The FDA recommends avoiding valproate altogether, if possible, in women of childbearing age.1

VALPROATE — Valproic acid and divalproex sodium dissociate to valproate in the GI tract. Valproate is considered the drug of choice for treatment of primary generalized tonic-clonic seizures. It is one of many drugs used for treatment of bipolar disorder and prevention of migraine.2,3

EFFECTS ON CHILDREN — The recent publication is the third in a series comparing IQ scores in a cohort of children exposed to various antiepileptic drugs throughout pregnancy.4 At 3 years of age, 4.5 years, and now 6 years, IQ scores were 6-11 points lower in children exposed to valproate than in those exposed to carbamazepine, lamotrigine or phenytoin. In addition, valproate taken during pregnancy has the highest demonstrated risk, compared to other antiepileptic drugs, of major congenital malformations, including oral cleft, cardiac, urinary tract and neural tube defects, and most recently, it has been associated with an increased risk of autism.5,6

USE IN MIGRAINE — Beta blockers such as propranolol and timolol and the antiepileptics valproate and topiramate are the drugs generally used for prevention of migraine. There is no evidence that any one is more effective than any other. Because of concerns about possible adverse fetal effects with all of these agents, preventive therapy for migraine is generally not recommended during pregnancy.7

CONCLUSION — Taking valproate during pregnancy can lower the IQ of exposed children and possibly could have other devastating effects. Those risks are certainly not worth taking for prevention of migraine.

1. FDA Drug Safety Communication: Valproate anti-seizure products contraindicated for migraine prevention in pregnant women due to decreased IQ scores in exposed children. Available at www.fda.gov/Drugs/DrugSafety/ucm350684.htm. Accessed May 28, 2013.

2. Drugs for psychiatric disorders. Treat Guidel Med Lett 2013; 11:53.

3. SD Silverstein et al. Evidence-based guideline update: pharmacologic treatment for episodic migraine prevention in adults: report of the Quality Standards Subcommittee of the American Academy of Neurology and the American Headache Society. Neurology 2012; 78:1337.

4. KJ Meador et al. Fetal antiepileptic drug exposure and cognitive outcomes at age 6 years (NEAD study): a prospective observational study. Lancet Neurology 2013; 12:244.

5. J Christensen et al. Prenatal valproate exposure and risk of autism spectrum disorders and childhood autism. JAMA 2013; 309:1696.

6. KJ Meador and DW Loring. Risks of in utero exposure to valproate. JAMA 2013; 309:1730.

7. Drugs for migraine. Treat Guidel Med Lett 2011; 9:7.

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Treatment of epilepsy should begin with a single drug, increasing the dosage gradually until seizures are controlled or adverse effects become unacceptable. If seizures persist, expert clinicians generally prescribe at least one and sometimes a second alternative drug as monotherapy before considering use of two drugs at the same time. When used for the appropriate seizure type, antiepileptic drugs are roughly equivalent in efficacy. The choice of drug is usually based on factors such as ease of use, adverse effects, interactions with other drugs, presence of comorbid conditions and cost.

Treatment of epilepsy should begin with a single drug, increasing the dosage gradually until seizures are controlled or adverse effects become unacceptable. If seizures continue and further dosage increases appear inadvisable because of adverse effects, most Medical Letter consultants generally prescribe at least one and sometimes a second alternative drug as monotherapy before considering use of two drugs at the same time. Most antiepileptic drugs initially approved by the FDA only as adjunctive therapy for partial seizures may also be effective for other types of seizures and as monotherapy. Studies suggest that when used for the appropriate seizure type, antiepileptic drugs are roughly equivalent in efficacy. The choice of a drug is usually based on factors such as ease of use, adverse effects and cost.

Treatment of epilepsy should begin with a single drug, increasing the dosage gradually until seizures are controlled or adverse effects become unacceptable. If seizures continue and further dosage increases appear inadvisable because of adverse effects, most Medical Letter consultants generally prescribe at least one and sometimes a second alternative drug as monotherapy before considering use of two drugs at the same time. Most antiepileptic drugs initially approved by the FDA only as adjunctive therapy for partial seizures may also be effective for other types of seizures and as monotherapy.

Treatment of epilepsy should begin with a single drug, increasing the dosage gradually until seizures are controlled or adverse effects become unacceptable. If seizures continue and further dosage increases appear inadvisable because of adverse effects, most Medical Letter consultants generally prescribe at least one and sometimes a second alternative drug as monotherapy before considering use of two drugs at the same time. Most antiepileptic drugs initially approved by the FDA only for adjunctive therapy are probably also effective as monotherapy. Many of the drugs used to treat epilepsy interact with each other (see table beginning on page 63) and with other drugs; for interactions with other drugs, see The Medical Letter Handbook of Adverse Drug Interactions, 2003. The treatment of status epilepticus is not included here.

Anticonvulsants are now widely used for treatment of psychiatric illnesses, particularly bipolar disorder. Lithium is the standard drug for treatment of bipolar disorder, but it can cause severe toxicity, serum concentrations must be monitored, and it is not effective in some patients.