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Painkiller DARVOCET Now Phased Out of U.K. Market; Still Widely Prescribed in the U.S.

Worst Pills, Best Pills Newsletter article January, 2008

The beginning of 2008 marks the end of the United Kingdom’s two-year phase-out of the combination propoxyphene and acetaminophen (DARVOCET), the narcotic painkiller which has been pulled from the U.K. market due to high numbers of accidental and intentional overdoses and deaths.

In 2005, British health authorities ordered a phased withdrawal of the drug, known in the U.K. as co-proxamol. It was withdrawn gradually rather than immediately because the narcotic has addictive properties and...

The beginning of 2008 marks the end of the United Kingdom’s two-year phase-out of the combination propoxyphene and acetaminophen (DARVOCET), the narcotic painkiller which has been pulled from the U.K. market due to high numbers of accidental and intentional overdoses and deaths.

In 2005, British health authorities ordered a phased withdrawal of the drug, known in the U.K. as co-proxamol. It was withdrawn gradually rather than immediately because the narcotic has addictive properties and patients require adequate time to switch to other painkillers.

Yet the U.S. Food and Drug Administration (FDA) has taken no steps to remove this dangerous drug from the U.S. market.

Almost two years ago, Public Citizen’s Health Research Group filed a petition with the FDA proposing a phased withdrawal of all drugs containing propoxyphene as an ingredient from the market. The agency has yet to respond to our petition, and the drug remains widely prescribed. In 2006, 22 million prescriptions for just the combination of propoxyphene and acetaminophen were filled in U.S. pharmacies, making it the 17th most-prescribed generic drug in this country.

According to British health authorities, the drug was banned because “each year there are 300- 400 fatalities following deliberate or accidental drug overdose involving  propoxyphene/acetaminophen in England and Wales alone. Approximately one-fifth [60-80] of these deaths are considered to be accidental.” The British government further stated that the drug’s effectiveness “is poorly established and the risk of toxicity in overdose, both accidental and deliberate, is unacceptable.... It has not been possible to identify any patient group in whom the risk-benefit [ratio] may be positive.” In other words, there is no group of people for whom the benefits outweigh the risks.

Not surprisingly, the number of accidental deaths in the U.S. is even higher: more than 2,500 accidental deaths have been reported in association with propoxyphene in the U.S. since 1981.

Drug unsafe, unimpressive painkiller
Multiple controlled clinical trials, the “gold standard” in research on drugs, have shown that propoxyphene is a relatively weak painkiller. In a study published almost 40 years ago in the Journal of the American Medical Association, propoxyphene was found to be no more effective than two aspirin tablets.

Further, the drug has dangerous side effects. When propoxyphene is broken down in the body, it is converted into a compound that is toxic to the heart.

The drug has a very small margin of safety – a dangerous dose is only slightly higher, or may be no higher than an effective dose. The safety margin can become even more unfavorable to patients taking the drug who have not experienced relief and thus take more of the drug, accidentally causing heart toxicity.

What You Can Do
Patients taking a propoxyphene-containing product should consult their physician about switching to a safer, more effective painkiller.

Do not stop taking propoxyphene suddenly. Withdrawal symptoms may occur. Discontinue under a physician’s supervision only.