- Impaired liver function (e.g., alanine aminotransferase [ALT] ≥2 times the upper limit of normal [ULN] or bilirubin ≥2 times ULN), known active hepatic disease (e.g., hepatitis), or evidence of clinically significant liver disease or other condition affecting the liver that may suggest the potential for an increased susceptibility to hepatic toxicity with oral gabapentin or pregabalin exposure.