Propoxyphene napsylate.

Propoxyphene napsylate differs from the hydrochloride salt in several ways. It is much less soluble and bitter and poses few stability problems when capsulated or tableted with aspirin. There is some evidence in several animal species that the pattern and severity of poisoning may be different with the two salts. Equimolar doses of the two salts are probably interchangeable in the relief of pain. The role of propoxyphene in clinical medicine and the questions of propoxyphene abuse and propoxyphene-related fatalities are discussed.