Influence of naloxone on relief of acute oro-facial pain by transcutaneous electrical nerve stimulation (TENS) or vibration.

Twenty-eight patients suffering acute pain following operative removal of impacted third molars took part in the present study. In 20 patients who reported pain reduction exceeding 25% of the initial pain intensity during vibratory stimulation (100 Hz) or TENS (2 or 100 Hz), only 1 patient (given 2 Hz TENS) reported pain increase after injection of 0.8 mg naloxone (i.v.). In 8 patients, not treated with afferent stimulation, 2 experienced increase in pain intensity after naloxone injection. The results show that pain relief using TENS or vibration is not influenced by naloxone.