Rezulin (Troglitazone), developed and marketed by Warner-Lambert/Parke-Davis, is used to treat Type 2 Diabetes. Rezulin makes the body's use of insulin more efficient, thereby improving glucose control. Pfizer Inc. acquired Warner-Lambert Company in July, 2000.
Rezulin proved extremely popular starting with its release in 1997, and soon approximately 1 million diabetes patients were taking the medication. It was known even at that time that Rezulin was associated with liver damage in some users. As a result, regular testing was instituted to monitor the liver health of Rezulin users, with testing to occur about once per month. However, some users experienced very rapid onset of liver toxicity within the weeks between their scheduled tests.
Liver toxicity caused by Rezulin can result in liver failure, necessitating liver transplant or causing death. Sympoms of this liver toxicity include jaundice, loss of appetite, nausea, abdominal pain, fatigue, and darkened urine. Among users of Rezulin, there have been at least thirty-eight cases of acute liver failure.
Following a safety review by the FDA, in March, 2002, Warner-Lambert/Parke-Davis announced its voluntarily withdrawal of Rezulin from the market. That FDA safety review involved the comparison of Rezulin to other similar drugs, and concluded that Rezulin was significantly more dangerous than available alternative medications, and that the risk of Rezulin use was unacceptable. Prior to its withdrawal from the market, Rezulin generated approximately 1.8 billion dollars in revenue for its manufacturer.
A number of individual and class action lawsuits were filed in relation to Rezulin injuries. In July, 2004, Pfizer settled an Illinois class action lawsuit filed over marketing practices used to advance the sales of Rezulin for $60 million. In announcing the settlement, Pfizer insisted that the medication was safe, and that the lawsuit was without merit.