Vioxx Scandal: Merck's COX-2 Painkiller That Caused Tens of Thousands of Heart Attacks
Merck's blockbuster {{COX-2 inhibitor}} {{rofecoxib}} (Vioxx), approved in 1999 and withdrawn in 2004, was estimated by FDA safety officer {{David Graham}} to have caused 88,000–139,000 heart attacks in the US alone before withdrawal, with 30–40% fatal.
Vioxx (generic name rofecoxib) was a COX-2 selective inhibitor painkiller developed by Merck, approved by the FDA on May 20, 1999 for osteoarthritis, rheumatoid arthritis, and acute pain. It became a blockbuster, reaching roughly $2.5 billion in annual revenue by 2003 with about 80 million patients worldwide and Dorothy Hamill as its public spokesperson. The VIGOR trial (March 2000, roughly 8,000 patients) compared Vioxx against naproxen and found 5 times more heart attacks in the Vioxx arm. Merck publicly pushed the naproxen hypothesis — the claim that naproxen was unusually cardioprotective rather than Vioxx being harmful. Internal Merck emails later revealed that company scientists already understood the real mechanism: Vioxx blocks COX-2-derived prostacyclin (an anti-clotting signal) while leaving COX-1-derived thromboxane (a pro-clotting signal) intact, tipping coagulation toward clot formation. Merck quietly explored anti-clotting reformulations during this period. In 2002, the FDA required Merck to add a cardiovascular warning to the Vioxx label; marketing continued at scale. In September 2004, the FDA approved Vioxx for juvenile rheumatoid arthritis just weeks before the drug was pulled. The APPROVe trial — a placebo-controlled study of Vioxx for colon polyp prevention — showed roughly 2 times the heart attack rate at the 18-month mark, with no naproxen arm to provide cover. The trial's independent safety monitoring board halted it, and Merck withdrew Vioxx globally on September 30, 2004, losing roughly $25 billion in market capitalization in one day. In November 2004, FDA safety officer David Graham testified before the Senate Finance Committee that Vioxx had caused an estimated 88,000–139,000 heart attacks in the US, with 30–40% fatal. His analogy — equivalent to two to four fully loaded jumbo jets crashing every week for five years — became the defining quantification of the toll. In 2007, Merck reached a $4.85 billion global civil settlement covering roughly 27,000 lawsuits, with no admission of guilt. Merck stock rallied on the news because the figure was well below the previously feared $25–50 billion in exposure. In November 2011, the Department of Justice settled criminal proceedings with a single misdemeanor plea for off-label marketing to juveniles and $950 million in penalties — roughly five months of peak Vioxx revenue. No individual Merck executive was charged. CEO Raymond Gilmartin retired with tens of millions of dollars in compensation. The 2007 FDA Amendments Act was a direct legislative response, giving the FDA new authority to mandate post-market safety studies.