Low-dose methadone has an analgesic effect in neuropathic pain: a double-blind randomized controlled crossover trial

The analgesic effectiveness and adverse effect incidence of a daily dose of 10 or 20 mg of oral methadone were evaluated in 18 patients with a diverse range of chronic neuropathic pain syndromes, who had all responded poorly to traditional analgesic regimens. Analgesia was seen after each dose of methadone. As compared with placebo, the 20 mg daily dose (given as 10 mg bd) resulted in statistically significant (P=0.013–0.020) improvements in patient Visual Analogue Scale ratings of maximum pain intensity, average pain intensity and pain relief, recorded at the same time daily. The analgesic effects extended over 48 hours, as shown by statistically significant (P=0.013–0.020) improvements in all three outcomes on the rest days instituted between each daily dose. Analgesic effects (lowered maximum pain intensity and increased pain relief, on the day of dosing only) were also seen when the lower daily dose of 10 mg methadone (given as 5 mg bd) was used, but these failed to reach statistical significance (P=0...