The antidiabetic drug troglitazone has been taken off the market in the United States because the Food and Drug Administration says that it has been shown to be more toxic than newer drugs in the class.
The FDA announced on March 21 that it had asked troglitazone's manufacturer Warner Lambert to withdraw the drug. This followed a review, which showed that rosiglitazone and pioglitazone, both approved in the US last year, "offer the same benefits as troglitazone without the same risk". The FDA added: "After up to nine months of marketing experience with these two newer drugs, it has now become clear that these newer drugs have less risk of severe liver toxicity than troglitazone."
In the UK, troglitazone, marketed by Glaxo Wellcome, was withdrawn in 1997, after only two months on the market, because of hepatic toxicity. It remained available in the US but with strict requirements for liver monitoring. Neither rosiglitazone (Smithkline Beecham) nor pioglitazone (Lilly) is licensed in the UK but rosiglitazone was recently recommended for European licensing by the Committee for Proprietary Medicinal Products (PJ, March 25, p461).