Both darvon (proproxyphene hydrochloride) and darvocet (proproxyphene napsylate with apap) or darvon-n (plain proproxyphene hydrochloride) are approximately 1-2 to 2/3 the strength of 60 mg of codeine. But their real use often is as a kick pill for people addicted to heroin, or those coming down from heavy hydro habits because they're cross tolerant. They're cousins to methadone, very weak ones. People on the methadone program claim they are equal to about 2.5 mg, a "half a capful" and use them to boost their dose. They're hard on the liver, especially darvocet, which contains 650mg apap. They do do something when mixed with valium that is more severe than on their one. They stay in your system a long time. In terms of killing heavy pain, they don't really work well. And they can give you breathing stops. Remember the rock journalist Lester Bangs? He OD'd from them, they can cause pulmonary edema (fluid in the lungs) - in fact the PDR warns against giving them out to suicidal individuals. So for a "minor" painkiller they're actually more dangerous than hydro or percs. If I was in any serious pain I'd reject them immediately, and probably would, anyway.