Hepatic cirrhosis associated with long-term primidone therapy in a dog

The anticonvulsant drug, primidone, was believed to be responsible for the development of hepatic cirrhosis in a 9-year-old German Shepherd Dog with idiopathic epilepsy. Marked increases in serum alanine aminotransferase, serum alkaline phosphatase, total bilirubin, and sulfobromophthalein retention, as well as decreases in albumin and BUN supported the diagnosis of hepatic failure. Biochemical abnormalities improved after primidone was discontinued. Previous reports indicated a poor prognosis for anticonvulsant-induced hepatic failure; however, this dog has remained stable for over a year after diagnosis and proper therapy.