According to a recently concluded study, four years before Merck’s anti-inflammatory medication was taken off the market, various studies had already linked it to substantial cardiovascular dangers, information not available to consumers and physicians at the time.

Newly published research in the Archives of Internal Medicine, researchers analyzed 30-studies for their study, of which 12 were not available to the public at the time Vioxx was still on the market. It was only after the filing of lawsuits by consumers harmed by the drug that they were made available. The studies, involving over 20,000-people, showed those who were taking Vioxx had an increased risk of heart attacks, strokes and hypertension.

In 2004, the non-steroidal anti-inflammatory medication was withdrawn from the market, when the risk became public. The US Food and Drug Administration (FDA) expressed concerns about the effect of Vioxx on the heart before it was even approved in 1999. By June 2001, on completion of most of the 30-studies, there was conclusive evidence of a 35% increase in a cardiovascular event or death risk among users.

The authors of a commentary accompanying the study say, concerns expressed by some medical experts about Vioxx were lost amidst Merck & Co.’s direct-to-consumer marketing.

Disagreeing with the study’s conclusions, Merck officials in their statement released Monday say, unreliable methods were used by the Mount Sinai investigators to assess the data.

The Vioxx controversy lead to the enactment of new government regulations requiring public disclosure of study results within 12 to 24-months of completion on both drug efficacy and safety. However, some loopholes remain, as manufacturers are only required to report clinical trial summaries, not individual reports of the side effects.