Double-blind randomized trial of tramadol for the treatment of the pain of diabetic neuropathy.
OBJECTIVE
The objective of this study was to evaluate the efficacy and safety of tramadol in treating the pain of diabetic neuropathy.


BACKGROUND
The pain of diabetic neuropathy is a major cause of morbidity among these patients and treatment, as with other small-fiber neuropathies, is often unsatisfactory. Tramadol is a centrally acting analgesic for use in treating moderate to moderately severe pain.


METHODS
This multicenter, outpatient, randomized, double-blind, placebo-controlled, parallel-group study consisted of a washout/screening phase, during which all analgesics were discontinued, and a 42-day double-blind treatment phase. A total of 131 patients with painful diabetic neuropathy were treated with tramadol (n=65) or placebo (n=66) tramadol, which were administered as identical capsules in divided doses four times daily. The primary efficacy analysis compared the mean pain intensity scores in the tramadol and placebo groups obtained at day 42 of the study or at the time of discontinuation. Secondary efficacy assessments were the pain relief rating scores and a quality of life evaluation based on daily activities and sleep characteristics.


RESULTS
Tramadol, at an average dosage of 210 mg/day, was significantly (p < 0.001) more effective than placebo for treating the pain of diabetic neuropathy. Patients in the tramadol group scored significantly better in physical (p=0.02) and social functioning (p=0.04) ratings than patients in the placebo group. No statistically significant treatment effects on sleep were identified. The most frequently occurring adverse events with tramadol were nausea, constipation, headache, and somnolence.


CONCLUSIONS
The results of this placebo-controlled trial showed that tramadol was effective and safe in treating the pain of diabetic neuropathy.
Harati
Y
Y
Baylor College of Medicine and Veterans Affairs Medical Center, Houston, TX 77030, USA.
Gooch
C
C
Swenson
M
M
Edelman
S
S
Greene
D
D
Raskin
P
P
Donofrio
P
P
Cornblath
D
D
Sachdeo
R
R
Siu
C O
CO
Kamin
M
M
D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000701:Analgesics, Opioid / Q000009:adverse effects / Q000627:therapeutic use*; D003929:Diabetic Neuropathies / Q000188:drug therapy* / Q000503:physiopathology; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000503:physiopathology; D010166:Palliative Care; D011788:Quality of Life; D012890:Sleep / Q000502:physiology; D014147:Tramadol / Q000009:adverse effects / Q000627:therapeutic use*
D000701:Analgesics, Opioid; D014147:Tramadol