Propoxy Questions

Propoxy is an abbreviation of the chemical name propoxyphene, an opioid painkiller. Xanodyne, Inc,. sells propoxyphene under the brand names of Darvon (propoxyphene alone) and Darvocet or Darvocet-N (propoxyphene plus acetaminophen). On November 19, 2010, the Food and Drug Administration (FDA) voted to recommend the withdrawal of all brand name and generic forms of propoxyphene from the market.

Why Did the FDA Recommend Banning Propoxyphene?

• In 1976, the FDA approved propoxyphene as a Schedule IV Controlled Substance for the treatment of mild to moderate pain. As soon as 1978, the FDA received citizen petitions noting the drug's effect on patients' heart rhythm and requesting the removal of propoxyphene from the market. However, the FDA did not find that the side effects outweighed the benefits. Additional petitions were issued in 2006 and 2009. The 2009 petition cast enough doubts on the efficacy of propoxyphene that the FDA asked Xanodyne, Inc., to perform a study specifically measuring the drug's effects on the heart function of healthy subjects. The results were significant enough to recommend pulling propoxyphene from the market.

What Were the Study's Findings?

• Xanodyne, Inc., conducted a study in which the dosage of participants varied. Researchers monitored the QT intervals, which is the time between hearbeats, of the participants. Those subjects receiving 600 mg doses and those receiving 900 mg doses both saw spikes in their QT intervals. The 600 mg group saw an average change of 29.8 milliseconds, and the 900 mg group saw an average change of 38.2 milliseconds. The International Conference on Harmonisation (ICH) E14 Guideline1 states that any drug causing a QT interval greater than 20 milliseconds promotes arrhythmic conditions or irregular heartbeats. This could lead to low blood pressure, fainting, tachycardia or significant cardiac arrest.

How Do I Know If I Am Taking Propoxyphene?

• Check the label of your pain medication. The label may carry any one of these names, depending on whether it is a brand name or generic version: Darvon, Darvocet, Darvocet A500, Darvocet-N, propoxyphene, propoxyphene-N acetaminophen or proxoxyphene napsylate. If you are still uncertain, contact your doctor or pharmacist.

What Should I Do If I Am Taking Propoxyphene?

• Contact your doctor immediately and schedule an appointment to discuss alternative medicines. Currently, Xanodyne, Inc., voluntarily ceased production of propoxyphene medications, and the FDA has requested that generic manufacturers also comply. However, generic propoxyphene is still available. Even if you have taken propoxyphene without adverse side effects, you should talk to your doctor about alternative medications because you may not be able to purchase propoxyphene in the future.

Should I Stop Taking Propoxyphene Today?

• Do not stop taking propoxyphene without first consulting your doctor. You must slowly wean off propoxyphene to avoid developing withdrawal symptoms. In addition, you should have a backup pain medication ready to prevent a worsening of your condition.

I Have Been Taking Propoxyphene For 10 Years, Should I Be Concerned?

• According to Gerald Dal Pan, MD, MHS, director of the FDA's office of surveillance and epidemiology, long-term users of propoxyphene should not worry about adverse heart problems due to prolonged use of the drug. The effects of propoxyphene are not cumulative. However, changes in your medication or a worsening of your condition, particularly a decrease in kidney function, may increase your risk of developing arrhythmia.

How Do I Dispose Of Propoxyphene Pills?

• The FDA recommends mixing pills with coffee grounds or other garbage to make them unappetizing to children or anyone else who might go through your garbage. Alteratively, you can seal them in screw top bottles or other sealable containers and place them in the trash. Do not flush pills down the toilet or grind them in the garbage disposal.