What is propoxyphene/acetaminophen?

Darvocet: A pain killer which has been removed off the market due to association with cardiac toxicity.

Treat pain: but propoxyphene (or Darvon) is no longer available in the US. This product, which is chemically quite close to methadone, was felt by many authorities to be an expensive and potentially dangerous placebo, and many studies of darvon failed to show any real analgesic effect outside of the apap (tylenol) part. Was shown to cause heart rhythm problems and was taken off market in 90s in US.