Methadone in the treatment of neuropathic pain.
BACKGROUND
Methadone, being an N-Methyl-D-Aspartate receptor antagonist, may have a potential role in the treatment of neuropathic pain.


OBJECTIVE
To evaluate the effect of methadone in the treatment of neuropathic pain and to estimate the possible dose ranges needed for pain control.


METHODS
Methadone was offered as a treatment option to consecutive cancer and noncancer patients with neuropathic pain. Pain intensity was measured by the visual analogue scale (VAS) (0-10 cm where 0 = no pain and 10 = worst possible pain). Mechanical allodynia and paroxysmal (shooting) pain were assessed clinically. All assessments were collected prospectively before treatment and once a stable dose of methadone was reached.


RESULTS
A total number of 18 patients met our inclusion criteria. The mean pretreatment VAS +/- SD was 7.7+/-1.5 cm and this dropped significantly to 1.4+/-1.7 cm on a stable dose of methadone (P<0.0001). Nine of 13 patients (70 %) had a complete resolution of mechanical allodynia and all eight patients (100%) with shooting pain reported a complete response. The median stable dose of methadone was 15 mg per day.


CONCLUSIONS
Methadone at relatively low doses seems to be useful in the treatment of neuropathic pain.
Gagnon
Bruno
B
Royal Victoria Hospital, Montreal, Canada. bruno.gagnon@clinepi.mcgill.ca
Almahrezi
Abdulaziz
A
Schreier
Gil
G
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008691:Methadone / Q000494:pharmacology* / Q000627:therapeutic use*; D008875:Middle Aged; D020422:Mononeuropathies / Q000188:drug therapy* / Q000503:physiopathology; D010147:Pain Measurement / Q000187:drug effects* / Q000379:methods; D010148:Intractable Pain / Q000188:drug therapy / Q000503:physiopathology
D008691:Methadone