When the Food and Drug Administration (FDA) took a closer look at the widely prescribed painkiller propoxyphene, known by the brand names Darvon and Darvocet, they discovered just how deadly the drug was.
Sure, it had been targeted by citizen groups who wanted the drug removed from the market years ago because of its high dependency and overdose risk. Overdoses of propoxyphene can be lethal, and combining the medication with other drugs or alcohol can have deadly results. These findings resulted in an FDA warning about the potential for overdose associated with the drug.
The elderly and patients with impaired kidney function were found to be at an even greater risk for toxicity because they tend to have a more difficult time fully eliminating the active ingredient through the kidneys. This can cause a buildup of the drug in the body that only compounds when a new dose is taken.
This accumulation of propoxyphene in the system was soon associated with serious cardiac problems that include bradycardia, decreased contractility, decreased electrical conductivity and prolonged QRS-intervals, which can be deadly. This was enough to get the FDA’s attention.
Then the FDA reviewed data from numerous sources, including The Drug Abuse Warning Network Emergency Department (DAWN-ED), The Drug Abuse Warning Network Examiner (DAWN-NE), and the Florida Department of Law Enforcement, and found that propoxyphene was associated with a higher frequency of deaths compared to the pain relievers tramadol and hydrocodone.
Over a five-year period, the number of drug-related deaths was approximately 16 deaths per 100,000 prescriptions for propoxyphene, compared to 10 deaths per 100,000 perscriptiosn for tramadol, and 8 deaths per 100,000 prescriptions for hydrocodone.
Finally, after more than 50 years on the market, the FDA banned propoxyphene-containing drugs. What took the agency so long to protect the public from this dangerous medication?