Feds Pull Popular Pain Killer Darvocet Off the Market

WASHINGTON

The United States Food & Drug Administration has announced that the popular prescription drugs Darvon and Darvocet have been voluntarily pulled off the American market.  This move came after pressure from the FDA on the drug’s maker Xanodyne Pharmaceuticals to pull the drug, although no official mandates came down to enforce the FDA’s request.

Darvon and Darvocet are branded versions of the painkiller propoxyphene; an opioid based medication that is used to treat mild to moderate pain.  The drugs, which are similar to codeine, bind with opioid receptors in the brain to produce an analgesic and antitussive effect.  Darvon is the pure version of the drug, while Darvocet is a version that is mixed with acetaminophen.

The FDA requested that Xanodyne Pharmaceuticals remove the branded drugs from the US market in response to numerous reports and studies that indicate that taking propoxyphene can lead to serious, potentially fatal heart arrhythmias.  Additionally, the drug has been cited as being highly addicting and poses a serious risk for dependency and abuse.

Doctors in the United States were cautioned by the FDA to stop prescribing the drugs immediately.  Patients, on the other hand, were advised to continue taking any Darvon or Darvocet that they may currently be on and contact their health care provider as soon as possible to make arrangements for a reduced dosage and/or switch to another type of medication.

Healthcare officials have stated that it is extremely important that patients currently on propoxyphene continue to take the drug, as sudden reductions in dosage or stopping the drug altogether can have serious adverse side effects that could potentially lead to death.  This is because propoxyphene builds up tolerance in the human body over time.  Tolerance is the body’s natural response to foreign drugs in the system.  Essentially, the central nervous system will make changes to the body’s chemistry in order to cope with the drug.

Tolerance quickly leads to physical dependence, which is not the same as outright addiction.  In either case, patients who are in various stages of tolerance or dependency could place themselves in danger by discontinuing using propoxyphene suddenly.  Because the body has made chemical changes to compensate for the high level of drugs in the system, those changes will need to be reversed when the drug is no longer present in the bloodstream.  This causes painful and possible fatal side effects known as withdrawal syndrome.

Generic makers of propoxyphene pain medications were also requested to remove the drug from US shelves.  To date, the FDA and the US Center for Disease Control report that all manufacturers of the drug have voluntarily complied with the federal agency’s request.

However, health care practitioners and patient’s advocacy groups have said that the move took far too long to implement, citing at least 2 other requests for the drug to be pulled off the US market.  The first recorded request came in 1978, when patient’s rights groups lobbied unsuccessfully to have propoxyphene taken off the market due to its high risk of heart complications.  However, at that time the FDA indicated that the drug’s benefits outweighed its risks and allowed the drug to remain on American pharmacy shelves.

Other countries have recognized the risk and taken action.  In 2005, the United Kingdom pulled the drug from its pharmacies and dispensaries, citing safety issues related to addiction, heart problems, and overdoses.  The entire European Union followed suit in 2009, removing the drug completely from the market after extensive reviews of studies that have pointed out potentially deadly side effects from propoxyphene.  European health officials also stated that the drug appeared to have a high association with suicides in addition to accidental overdoses.

For the 10 million people who have been prescribed the drug since 2009, the most serious risk is that the drug has been shown to interfere with the electrical functions of the heart, causing irregular heartbeats, arrhythmias, and possibly heart attacks.  However, officials from the FDA have stated that the effects of the drug are not cumulative, and that when a patient stops taking the drug, the risk is no longer present.

Public Citizen, a US citizen’s and patient’s rights group, lobbied for the removal of the drug in 1978 and again in 2006- after the United Kingdom had pulled the drug from its pharmacies.  The group cited extensive research that implicated propoxyphene- including Darvon and Darvocet, in the deaths of thousands of people.  The group has stated that the FDA’s announcement this week is welcome, but should have come sooner.

Darvon and Darvocet, first approved for use in 1957, will likely be replaced by codeine and oxycodone.  These drugs are also opioids but do not pose the same risks for heart troubles that propoxyphene does.  Like all opioids, codeine and oxycodone do present a high potential for abuse, overdose, and suicide- but these risks tend to remain constant throughout the opioid family of drugs.

So far, there have been no rumors of lawsuits as a result of this week’s FDA request for manufacturers to remove the drug from the US market.