Liver histologic findings were consistent with drug-induced liver injury. Although other causes of acute liver disease were not identified and biopsy results did not suggest chronic liver disease, the patient had risk factors for chronic liver disease. Nonalcoholic steatohepatitis causes slowly progressive fibrosis in some obese diabetic patients, but histologic examination of the liver did not show steatosis, inflammation, or sinusoidal fibrosis, characteristics that define this syndrome. Medullary sponge kidney is also associated with hepatic fibrosis in rare cases, but our patient did not have the characteristic ductal plate malformations and broad portal fibrosis. Of note, the patient became aware of possible troglitazone-induced hepatotoxicity through information available on the Internet.
Patients increasingly obtain information of varying accuracy from the Internet.
In this case, the patient identified relevant drug information before her physicians had received new monitoring recommendations from the manufacturer. Unfortunately, it was still too late to affect her outcome. The cause of troglitazone hepatotoxicity remains unknown. Troglitazone is primarily metabolized to sulfate and glucuronide conjugates in the liver. It also induces cytochrome P450 3A4 activity, and a small fraction undergoes cytochrome P450 oxidation to a quinone derivative.