Propoxyphene hydrochloride is a powerful pain relief medication that is now banned in most countries due to its high abuse potential and deadly side effects. However, there are several synonyms for this drug that might be useful to know for medical professionals or researchers studying this drug. Some of the alternatives to propoxyphene hydrochloride include Darvon, Darvocet, PPC, PPX, and CAP. These names are often used interchangeably or as brand names for specific formulations of propoxyphene hydrochloride, and they all have the same chemical structure and similar effects on the body. However, it is important to note that the use of this drug is highly restricted and it should only be prescribed by a licensed physician.