Ethotoin

Ethotoin can cause fetal harm when administered to a pregnant woman. There are multiple reports in the clinical literature which indicate that the use of antiepileptic drugs during pregnancy results in an increased incidence of birth defects in the offspring. Although data are more extensive with respect to phenytoin and phenobarbital, reports indicate a possible similar association with the use of other antiepileptic drugs. Therefore, antiepileptic drugs should be administered to women of child-bearing potential only if they are clearly shown to be essential in the management of their seizures.

Antiepileptic drugs should not be discontinued in patients in whom the drug is administered to prevent major seizures because of the strong possibility of precipitating status epilepticus with attendant hypoxia and risk to both mother and the unborn child. Consideration should, however, be given to discontinuation of antiepileptics prior to and during pregnancy when the nature, frequency and severity of the seizures do not pose a serious threat to the patient. It is not, however, known whether even minor seizures constitute some risk to the developing embryo or fetus.

Reports have suggested that the maternal ingestion of antiepileptic drugs, particularly barbiturates, is associated with a neonatal coagulation defect that may cause bleeding during the early (usually within 24 hours of birth) neonatal period. The possibility of the occurrence of this defect with the use of ethotoin should be kept in mind. The defect is characterized by decreased levels of vitamin k-dependent clotting factors, and prolongation of either the prothrombin time or the partial thromboplastin time, or both. It has been suggested that vitamin k be given prophylactically to the mother one month prior to and during delivery, and the infant, intravenously, immediately after birth.

If ethotoin is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus.

To provide information regarding the effects of in utero exposure to ethotoin, physicians are advised to recommend that pregnant patients taking ethotoin enroll in the North American Antiepileptic Drug (NAAED) Pregnancy Registry.

Ethotoin is excreted in breast milk. Because of the potential for serious adverse reactions in nursing infants from ethotoin, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

No data are available on long-term potential for carcinogenicity in animals or humans.

Adverse reactions associated with ethotoin, in decreasing order of severity, are:

Isolated cases of lymphadenopathy and systemic lupus erythematosus have been reported in patients taking hydantoin compounds, and lymphadenopathy has occurred with ethotoin. Withdrawal of therapy has resulted in remission of the clinical and pathological findings. Therefore, if a lymphoma-like syndrome develops, the drug should be withdrawn and the patient should be closely observed for regression of signs and symptoms before treatment is resumed.

Ataxia and gum hypertrophy have occurred only rarely—usually only in patients receiving an additional hydantoin derivative. It is of interest to note that ataxia and gum hypertrophy have subsided in patients receiving other hydantoins when ethotoin (ethotoin tablets, USP) was given as a substitute antiepileptic.

Occasionally, vomiting or nausea after ingestion of ethotoin has been reported, but if the drug is administered after meals, the incidence of gastric distress is reduced. Other side effects have included chest pain, nystagmus, diplopia, fever, dizziness, diarrhea, headache, insomnia, fatigue, numbness, skin rash, and Stevens-Johnson syndrome.