UPTAKE OF ETORPHINE AND DIHYDROMORPHINE AFTER SUBLINGUAL AND INTRAMUSCULAR ADMINISTRATION

Preliminary studies using the dog indicated that the highly potent analgesic etorphine is relatively much more effective than morphine, after sublingual administration. Experiments using tritium labelled materials showed that this difference between the drugs could probably be explained by the fact that etorphine, unlike dihydromorphine, passes rapidly across the buccal mucosa into the systemic circulation. Etorphine was also found to pass extremely rapidly from an intramuscular site into the blood stream, and this is thought to contribute to its rapid onset of action, when given by this route. © 1969.