Xanodyne Pharmaceuticals Agrees to Withdraw Propoxyphene at FDA’s Request

• Date: November 26, 2010
• Source: Admin

Propoxyphene, which is sold under the brand names Darvocet, Darvon, Darvon-N, and Dolene is a narcotic pain-reliever. It is a cough suppressant but is weaker than morphine. Its precise mechanism of action is not known but may involve the stimulation of opioid (narcotic) receptors in the brain. Propoxyphene increases pain tolerance and decreases discomfort but the presence of pain is apparent. Additionally, propoxyphene causes sedation and respiratory depression. The FDA approved propoxyphene in August 1957. An estimated 10 million patients have used propoxyphene-based products since.

Anticipated Troubles Caused by Propoxyphene

New clinical data shows that when propoxyphene is taken at therapeutic doses, there are significant changes to the electrical activity of the heart: prolonged PR interval, widened QRS complex and prolonged QT interval. These changes can increase the risk for serious abnormal heart rhythms. At a press conference, John Jenkins, MD, director of the Office of New Drugs, said the new numbers tipped the risk–benefit ratio against the drug.

The US Food and Drug Administration (FDA) has therefore revoked its approval of the drug and asked Xanodyne Pharmaceuticals to recall it from the US market containing. This decision will also affect generic manufacturers and the makers of Propoxyphene- products.  The latter should also recall their products. FDA has notified healthcare professionals that Xanodyne Pharmaceuticals had agreed to withdraw propoxyphene, with the new data showing that it can cause serious cardiac toxicity, even at therapeutic doses.

Health care professionals have been advised by the FDA to stop prescribing and dispensing propoxyphene-containing products to patients. Further, they have also been requested to contact patients, currently on propoxyphene-containing products and advise them of the risks associated with propoxyphene, and discuss alternative pain management strategies. Patients have been advised to dispose of unused propoxyphene in household trash in line with the Federal Drug Disposal Guidelines.

Propoxyphene gives rise to the following side effects:

• Lightheadedness
• Dizziness
• Sedation
• Nausea
• Vomiting
• Drowsiness,
• Constipation
• Propoxyphene can depress breathing and should be used with caution in elderly, debilitated patients and in patients with serious lung disease.
• It can impair thinking and the physical abilities required for driving or operating machinery.
• Propoxyphene may be habit-forming.

Petitions against Darvon till Date

In June 2008, the consumer interest group Public Citizen filed a federal lawsuit against the U.S. Food and Drug Administration in Washington, D.C. The lawsuit alleged that the agency violated the law by failing to act on a petition it filed in 2006.  The petition sought the withdrawal of Darvocet , Darvon , and generic propoxyphene drugs from the market.  They had been associated with over 2,000 accidental deaths; they were physically addictive and no more effective than other safer painkillers. According to data compiled by the Federal Drug Abuse Warning Network, deaths related to Darvocet, Darvon and other generic propoxyphene drugs accounted for over 5% of all drug-related deaths between 1987 and 2006. In November 2010, four years after the petition was filed, the FDA mandated the withdrawal of Propoxyphene.

Sources:

http://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm234389.htm