Rezulin (troglitazone) — the Diabetes Pill Withdrawn in 2000 After 63 Liver-Failure Deaths
When the U.S. Food and Drug Administration asked Warner-Lambert to pull Rezulin from the market on 21 March 2000, it ended a three-year arc in which a celebrated first-in-class diabetes pill killed at least 63 people through liver failure while the warning that should have stopped it had been visible from before launch. Rezulin (troglitazone), the first thiazolidinedione — an oral “insulin sensitizer” acting on the PPAR-gamma receptor — was approved on 29 January 1997 and marketed as a breakthrough that let type 2 diabetics use their own insulin more effectively. The gap between that promise and the harm was not subtle: the drug produced idiosyncratic, sometimes fulminant hepatotoxicity, and Britain’s Glaxo Wellcome withdrew it from the U.K. market on 1 December 1997 — barely ten months after the U.S. approval — while the FDA kept it on American shelves for another twenty-eight months.
The signal was institutional, not merely clinical. The FDA medical officer originally assigned to the application, Dr. John Gueriguian, had recommended against approval over cardiac and liver concerns; he was removed from the review on 4 November 1996, and his negative analysis was purged from the official record before the drug was cleared on an expedited timeline. Within the first year of marketing, serious hepatotoxicity reports accumulated, and an internal FDA memorandum cited 135 reports of serious liver injury by late 1997. Public Citizen’s Health Research Group, led by Dr. Sidney Wolfe, petitioned for withdrawal in July 1998, asking the agency how many more Americans would have to die or need transplants.
The verdict is therefore plain at the outset: a profitable, regulator-blessed, heavily prescribed medicine reached nearly two million Americans while the evidence that condemned it — a foreign withdrawal, a buried internal review, mounting death reports, and an outside petition — sat fully legible in the record. The FDA’s response was incrementalism: four label changes between 1997 and 1999 adding ever-stricter liver-monitoring instructions that real-world prescribing could not reliably execute, rather than removal.
What finally forced the withdrawal was arithmetic the labels could not fix. Once two safer thiazolidinediones — rosiglitazone and pioglitazone — reached the market in 1999 without the same fatal liver signal, Rezulin’s risk-benefit case collapsed, and the FDA requested its removal on 21 March 2000. Litigation followed: Warner-Lambert, absorbed by Pfizer in 2000, ultimately resolved roughly 35,000 claims for an estimated $750 million, and “Rezulin” became a byword for how a buried safety review and an ignored foreign recall can keep a lethal drug on the market for years.