Intrathecal d-Ala2-d-Leu5-enkephalin (DADL) restores analgesia in a patient analgetically tolerant to intrathecal morphine sulfate

Abstract

DADL was administered to a patient who was analgetically tolerant to continuously infused, intrathecal morphine sulfate. DADL restored analgesia without respiratory depression but opiate withdrawal syndrome was not prevented. Somnolence, not responsive to naloxone but completely reversed with morphine, was seen as an idiosyncratic mu receptor opiate withdrawal symptom. Clonidine hydrochloride and decreasing doses of oral morphine were used to successfully treat the withdrawal syndrome, including somnolence. Further research is indicated to verify the findings of this one patient and investigate the efficacy of DADL to provide analgesia for morphine-tolerant patients.