Pharmaceutical

Critics: US, Canada took too long to pull Darvon, Darvocet from market

The painkiller propoxyphene, known by the brand names Darvon and Darvocet, has been outlawed by several countries; however, critics are asking why it took so long for the drug to be banned, especially in the United States and Canada.

Propoxyphene is a prescription treatment for mild to moderate pain. It has been on the market in the United States for more than 50 years and has become one of the country’s most prescribed painkillers. But concerns about the drug’s safety surfaced as early as 1978, when the American watchdog group Public Citizen petitioned the Food and Drug Administration (FDA) to ban the drug because it endangered the lives of those who used it.

The FDA refused to hear the group’s concerns, until 2006, when the group petitioned the agency again, citing similar safety concerns. At that time, the United Kingdom had just pulled propoxyphene from the market, calling it too dangerous for its citizens.

It wasn’t until three years later, after the European Medicines Agency banned propoxyphene-containing drugs from its market, that an FDA advisory panel reviewed the drug and voted to recommend to the FDA that the drug be withdrawn from the market. However, those concerns seemed to fall on deaf ears with the FDA.

The agency instead opted to keep the drug on the market until more data became available from a new safety review on the drug’s effects on the heart. Data from that study, revealed this fall, showed an alarming trend. Even moderate users of propoxyphene were at great risk for experiencing deadly heart rhythm abnormalities.

In November, the FDA finally voted to pull propoxyphene from the U.S. market.

It wasn’t until the U.S. made its move that Health Canada issued a withdrawal of Darvon from the Canadian market, a delay that critics say may have cost thousands of lives.