Epidural beta-endorphin in treatment of pain

Epidural administration of 3 mg of synthetic beta-endorphin produced analgesia in 10 patients with intractable pain due to disseminated cancer. Mean onset of relief of pain was 24 +/- 3 minutes and the mean duration of analgesia was 19 +/- 3 hours. The onset of analgesia produced by the epidural injection of beta-endorphin was slower and the duration less than those observed after intrathecal injection.