Trimethadione in pregnancy and breastfeeding


Risk Factor: D
Class: Central nervous system drugs/ Anticonvulsants

Contents of this page:
Fetal Risk Summary
Breast Feeding Summary

Fetal Risk Summary

Trimethadione is an oxazolidinedione anticonvulsant used in the treatment of petit mal epilepsy. Several case histories have suggested a phenotype for a fetal trimethadione syndrome of congenital malformations (1,2,3,4,5,6 and 7). The use of trimethadione in nine families was associated with a 69% incidence of congenital defects25 malformed children from 36 pregnancies. Three of these families reported five normal births after the anticonvulsant medication was stopped (1,4). The incidence of fetal loss in these families was also increased compared with that seen in the general epileptic population. Because trimethadione has demonstrated both clinical and experimental fetal risk greater than other anticonvulsants, its use should be abandoned in favor of other medications used in the treatment of petit mal epilepsy (8,9,10 and 11).

Features of Fetal Trimethadione Syndrome (25 cases) Feature No.* % Feature No.* % Growth: Cardiac: Prenatal deficiency 8

  • Septal defect 5
  • Postnatal deficiency 6
  • Not stated 4
  • Performance (19 cases): Patent ductus 4
  • Mental retardation 7
  • arteriosus Vision (myopia) 5
  • Limb: Speech disorder 4
  • Simian crease 7
  • Impaired hearing 2 8 Malformed hand 2 8 Craniofacial: Club foot 1 4 Low-set, cupped, or
  • 72 Genitourinary: abnormal ears Kidney and ureter 5
  • High-arched or cleft
  • 64 abnormalities lip and/or palate Inguinal hernia(s) 3
  • Microcephaly 6
  • Hypospadias 3
  • Irregular teeth 4 6 Ambiguous genitalia 2 8 Feature No.* % Feature No.* % Epicanthic folds 3
  • Clitoral hypertrophy 1 4 Broad nasal bridge 3
  • Imperforate anus 1 4 Strabismus 3
  • Other: Low hairline 2 8 Tracheoesophageal 3
  • Facial hemangiomata 1 4 fistula Unusual facies 3
  • Esophageal 2 8 (details not given) atresia *Not mutually exclusive.

    Breast Feeding Summary

    No data are available.



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