Trimethadione Chemical formula
Synonyms: Trimetadion; Trimetadiona; Trimetadionas; Trimetadioni; Trimethadion; Triméthadione; Trimethadionum; Trimethinum; Troxidone. 3,5,5-Trimethyl1,3-oxazolidine-2,4-dione.
Cyrillic synonym: Триметадион.

💊 Chemical information

Chemical formula: C6H9NO3 = 143.1.
CAS — 127-48-0.
ATC — N03AC02.
ATC Vet — QN03AC02.


In Eur., Int., and Jpn.

Ph. Eur. 6.2

(Trimethadione). Colourless or almost colourless crystals. Soluble in water; very soluble in alcohol. Protect from light.

💊 Profile

Trimethadione is an oxazolidinedione antiepileptic that has been given in the treatment of absence seizures refractory to other antiepileptics. However, because of its potential toxicity, other antiepileptics are preferred.


Trimethadione has been associated with acute attacks of porphyria and is considered unsafe in porphyric patients.


Characteristic congenital malformations, termed the fetal trimethadione syndrome, have been associated with the use of trimethadione in pregnancy. For comments on the management of epilepsy during pregnancy.

💊 Preparations

Published November 28, 2018.