In Brief: Propoxyphene Toxicity

Accumulation of metabolites of propoxyphene can lead to central nervous system, cardiac and respiratory depression; convulsions and cardiotoxicity have occurred.

Are You Glad Darvocet Got Pulled by the FDA? Are You Sure?

I know many palliative care practitioners were cheering the news that the world's least effective opioid propoxyphene (Darvocet (w/ APAP) /Darvon) (similar efficacy to acetaminophen) is being pulled off the market by the FDA. Along with meperdine (Demerol) I am not sure if a medicine exists that produces as much disdain as propoxyphene amongst palliative care clinicians.

Darvon Pulled From Market by F.D.A.

Britain banned it in 2005 and the European Union followed in 2009, based partly on reports of an unusual number of deaths involving propoxyphene in Florida, where medical examiners do more toxicology work.

Darvon: Pulled from the Market in 2011

Since 1978, the FDA has received 2 requests to remove propoxyphene from the market. In January 2009, an advisory committee voted 14 to 12 against the continued marketing of propoxyphene products. At that time, the committee called for additional information about the drug's cardiac effects. The information is in. Propoxyphene causes fatal heart rhythms.

Petition to ban all Propoxyphene (Darvon) products

Many studies have shown the relative ineffectiveness of propoxyphene as a painkiller. In a recent comprehensive review of randomized clinical trials, Collins, et al., found that for most kinds of pain (e.g., post-operative pain), ibuprofen is more effective than propoxyphene/acetaminophen (the latter, the ingredient in Tylenol). Further, codeine/acetaminophen was found to be more effective than propoxyphene/acetaminophen, although that difference was not statistically significant.

The Influence of Propoxyphene Withdrawal on Opioid Use in Veterans

Propoxyphene is a short-acting, Drug Enforcement Agency Schedule IV, synthetic opioid introduced in 1957 that was indicated for mild to moderate pain. Propoxyphene was formulated either by itself (Darvon 65mg) or in combination with other analgesics, most commonly with acetaminophen. When compared to other analgesics in acute and chronic pain, propoxyphene with acetaminophen was consistently shown to be equivalent or inferior to other commonly used analgesics.

The World Of Darvon

One explanation for Darvon's effectiveness may be psychological. Because a doctor prescribes Darvon, patients may merely believe it works and, in a way, will it to work. The bigger question concerning Darvon, however, is safety.

What Is Propoxyphene and Why Was It Banned?

There are plenty of opioid drugs that have not been removed from the market, so why was propoxyphene banned? Propoxyphene was banned in 2010 because it was linked to a higher risk of developing serious and sometimes fatal heart rhythm abnormalities, even when taken at recommended doses.