Abstract Primidone is metabolized either into phenylethylmalondiamide or phenobarbital. 2- Hydroxyprimidone was synthesized and tested as a potential intermediate common to these two biodegradation pathways in dogs as well as in vitro. On the other hand, the mechanism of the formation of α-phenyl-γ-butyrolactone during intoxication was investigated and the role of precursor played by the phenobarbital generated in vivo was shown.
