Heterocyclic phosphonium salts of the following compound ##STR1## wherein d is 1, 2 or 3; R is hydrogen or an alkyl containing 1-3 carbon atoms; R.sub.1, R.sub.2 and R.sub.3 is each an alkyl radical containing 1-6 carbon atoms, a cycloalkyl radical containing 5 or 6 carbon atoms, or ##STR2## wherein n is 0-4, and Y is hydrogen, halogen, alkyl containing 1-6 carbon atoms or alkoxy containing 1-6 carbon atoms; X.sup.- is a pharmacologically acceptable anion; and one of a and b is a double bond and the other is a single bond. The compounds display valuable pharmacological properties, and are particularly useful as analgesic agents.