Butalbital has the same chemical formula as talbutal but a different structure one that presents as 5-allyl-5-isobutylbarbituric acid.
3.
Although all known members of the class possess relevant enzyme induction capabilities the degree of inhibition overall as well as the impact on each specific enzyme span a broad range with phenobarbital and secobarbital being the most potent enzyme inducers and butalbital and talbutal being among the weakest enzyme inducers in the class.