Comparison of analgesic effects and patient tolerability of nabilone and dihydrocodeine for chronic neuropathic pain: randomised, crossover, double blind study.
OBJECTIVE
To compare the analgesic efficacy and side effects of the synthetic cannabinoid nabilone with those of the weak opioid dihydrocodeine for chronic neuropathic pain.


METHODS
Randomised, double blind, crossover trial of 14 weeks' duration comparing dihydrocodeine and nabilone.


METHODS
Outpatient units of three hospitals in the United Kingdom.


METHODS
96 patients with chronic neuropathic pain, aged 23-84 years.


METHODS
The primary outcome was difference between nabilone and dihydrocodeine in pain, as measured by the mean visual analogue score computed over the last 2 weeks of each treatment period. Secondary outcomes were changes in mood, quality of life, sleep, and psychometric function. Side effects were measured by a questionnaire.


METHODS
Patients received a maximum daily dose of 240 mg dihydrocodeine or 2 mg nabilone at the end of each escalating treatment period of 6 weeks. Treatment periods were separated by a 2 week washout period. Results Mean baseline visual analogue score was 69.6 mm (range 29.4-95.2) on a 0-100 mm scale. 73 patients were included in the available case analysis and 64 patients in the per protocol analysis. The mean score was 6.0 mm longer for nabilone than for dihydrocodeine (95% confidence interval 1.4 to 10.5) in the available case analysis and 5.6 mm (10.3 to 0.8) in the per protocol analysis. Side effects were more frequent with nabilone.


CONCLUSIONS
Dihydrocodeine provided better pain relief than the synthetic cannabinoid nabilone and had slightly fewer side effects, although no major adverse events occurred for either drug.


BACKGROUND
Current Controlled Trials ISRCTN15330757 controlled-trials.com] .
Frank
B
B
Pain Management Unit, Royal Victoria Infirmary, Newcastle upon Tyne NE1 4LP. bernhard.frank@ncl.ac.uk
Serpell
M G
MG
Hughes
J
J
Matthews
J N S
JN
Kapur
D
D
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000701:Analgesics, Opioid / Q000008:administration & dosage* / Q000009:adverse effects; D002908:Chronic Disease; D003061:Codeine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D013759:Dronabinol / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*; D006801:Humans; D008875:Middle Aged; D010146:Pain / Q000517:prevention & control*; D016896:Treatment Outcome
D000701:Analgesics, Opioid; C011941:nabilone; D013759:Dronabinol; C014481:dihydrocodeine; D003061:Codeine