These drugs are insulin-sensitizers that improve insulin sensitivity in skeletal muscle and suppress hepatic glucose output. Some drugs cause direct toxicity with predictable, dose-related injuries characteristic for the particular drug. Such reactions are characterized as idiosyncratic. Through the years, the distinction between the two types of reactions has become less clear. Thus, in situations previously thought to be allergic reactions in susceptible patients, there now appears to be damage directly to cell membranes as a result of drug toxicity.
Various drugs can produce what is essentially a cholestatic reaction.
Some drug induced liver damage is virtually indistinguishable from chronic hepatitis and may even progress to cirrhosis. Chronic liver injury that histologically mimics alcoholic liver disease is also capable of being produced by certain drugs. Significantly, these problems had been apparent while the drug was being tested according to Dr. Anne Peters, an endocrinologist at the University of California at Los Angeles. Instead, the drug was marketed without any recommendation for liver monitoring. Unfortunately, the injuries and deaths continued.