Efficacy and safety evaluation of pregabalin treatment over 52 weeks in patients with diabetic neuropathic pain extended after a double-blind placebo-controlled trial.
Aims/Introduction:  Diabetic peripheral neuropathy (DPN) is often associated with pain, and thus a new treatment option is anticipated. We recently showed the efficacy of pregabalin in a randomized, double-blind, placebo-controlled, 14-week trial in Japanese patients with painful DPN. In the present study, we evaluated the long-term efficacy and safety of pregabalin for the relief of painful DPN.


METHODS
A total of 123 patients were enrolled in a 52-week open-label study, from among those who participated in the preceding double-blind trial. The subjects received pregabalin 150-600 mg/day. Pain intensity was measured using the short-form McGill pain questionnaire (SF-MPQ: total score, visual analog scale and present pain intensity).


RESULTS
The efficacy parameter SF-MPQ showed a decrease over the treatment period. The changes in visual analog scale and present pain intensity at the final evaluation were -25.4 mm and -0.7, respectively, suggesting an analgesic effect of pregabalin. Commonly reported adverse events were somnolence, weight gain, dizziness and peripheral edema, but most of them were mild to moderate in intensity. No new concerns about safety as a result of long-term administration of pregabalin were identified.


CONCLUSIONS
The findings from this trial suggest that long-term treatment with pregabalin is beneficial for pain relief in patients with DPN. This trial was registered with ClinicalTrials.gov (no. NCT00553280). (J Diabetes Invest, doi: 10.1111/j.2040-1124.2011.00122.x, 2011).
Department of Diabetes and Metabolism, Iwate Medical University, Morioka, Iwate.
Jo
J
Satoh
Department of Molecular Pathology, School of Medicine, Hirosaki University, Hirosaki.
Soroku
S
Yagihashi
Department of Neurology, Aomori Prefectural Central Hospital, Aomori.
Masayuki
M
Baba
Clinical Research.
Makoto
M
Suzuki
Clinical Research.
Akio
A
Arakawa
Clinical Statistics, Pfizer Japan Inc., Tokyo, Japan.
Tamotsu
T
Yoshiyama
Diabetic peripheral neuropathy; Neuropathic pain; Pregabalin