On June 20, 1997, the FDA approved Posicor despite findings from a congestive heart failure study suggesting that it might fatally disrupt heart rhythm (arrhythmia) when used with other drugs. The 2,400-patient clinical study found that 142 patients suddenly died after taking either Posicor or a placebo. The patients given Posicor died at a rate about 10% greater than those who took a comparator.
Six months after approving Posicor, the FDA advised doctors of the pill's "life-threatening" danger. The agency announced that it had "received reports of dangerously lowered heart rates in about 20 patients." Roche, the manufacturer, thereafter agreed to change the label advising that Posicor should not be taken in combination with cholesterol-lowering drugs.
On June 8, 1998, after further reported complaints, Roche announced Posicor's withdrawal. Before it was removed from the market, Posicor caused multiple injuries and 24 deaths by interacting dangerously with other medications. Today, doctors suspect that Posicor may responsible in as many as 143 deaths.