Antiepileptic Drugs-Effect on the Pancreas

Exocrine pancreatic disease and pancreatitis have previously been reported in dogs treated for epilepsy with potassium bromide (KBr). A study of a new diagnostic test for canine pancreatic lipase immunoreactivity (cPLI) was performed to evaluate serum cPLI concentrations in dogs treated with KBr alone, phenobarbital alone, or a combination of KBr and phenobarbital. Serum cPLI is specifically of exocrine pancreatic origin, and studies suggest it is also highly sensitive for the diagnosis of pancreatitis. Of 337 serum samples, 98 were from dogs treated only with KBr, 118 were from dogs treated only with phenobarbital, and 121 were from dogs treated with both drugs. Twenty-three (6.8%) of the dogs treated with KBr and/or phenobarbital were found to have cPLI concentrations above the suggested cutoff value for pancreatitis (199.9 mcg/L). Because the samples were run blindly, it could not be determined whether these dogs had clinical signs of pancreatitis. The study indicates an increased risk for elevated serum cPLI levels in dogs treated with KBr and/or phenobarbital and suggests that dogs treated with these drugs should be evaluated for pancreatitis, especially if clinical signs are present. Further studies are necessary to determine 1) whether elevations of serum cPLI levels are caused by actual pancreatic inflammation or by induction of gene expression of pancreatic lipase and 2) whether elevations in serum cPLI levels correlate with clinical signs of pancreatitis.

COMMENTARY: The authors detail elevations in serum cPLI levels of dogs receiving KBr and/or phenobarbital and suggest that dogs receiving these drugs may be at risk for pancreatitis. Although preliminary data suggest that serum cPLI is sensitive for the diagnosis of pancreatitis, the study did not determine whether the dogs had clinical signs of pancreatitis or evaluate the clinical state of the dogs in any way. Further investigation is needed to determine whether the administration of these drugs has a causal effect on the development of pancreatitis in dogs and to determine the mechanism by which the administration of these drugs might increase serum cPLI levels.Serum pancreatic lipase immunoreactivity concentrations in dogs treated with potassium bromide and/or phenobarbital. Steiner JM, Xenoulis PG, Anderson JA, et al. VET THER 9:37-44, 2008.