Comparative Clinical Trail Of Safety And Tolerability Of Gabapentin Plus Vitamin B1/B12 Versus Pregabalin In The Treatment Of Painful Peripheral Diabetic Neuropathy

Abstract

Introduction: The B complex vitamins (B1 and B12) have been shown to have antiallodynic, antihyperalgesic and antinociceptive effect. Neuromodulators as gabapentin (GBP) and pregabalin (PGB) are effective in the treatment of painful peripheral diabetic neuropathy, but are related to occurrence of adverse events at high doses (sleepiness, vertigo and dizziness). The aim of this study was to evaluate the efficacy and safety on pain intensity reduces of GBP + B1/B12 versus PGB in patients with painful diabetic peripheral neuropathy of moderate to severe intensity. Methodology: Multicenter, randomized, single-blind study. 336 patients were evaluated, 181 with GBP + B1/B12 and 165 with PGB, with an intensity average of 7/10 on the numerical pain scale; 5 visits (12 weeks) were set. The visual analog scale (VAS), the numerical pain scale (END), the clinical global impression (IGC) and patient’s global impression of change (IGCP) were used for the efficacy analysis. Reported adverse events were analyzed to assess safety. Outcomes: Both drugs showed reduction in pain intensity, with no statistically significant difference (P= 0.900) between the two treatment groups, although the reduction in group GBP/B1/B12 was associated with doses of 300 - 1800 mg/d, compared with 300-600 mg/d of PGB. Regarding the IGC and IGCP, both drugs improved the perception of improvement, with no statistically significant difference observed between the two treatment groups between basal and final visit (P= 0.586 and P= 0.429) and (P= 0.893 and P= 0.276) respectively. Higher frequency of dizziness (P = 0.012), and vertigo (P= 0.006) were observed in the group using PGB. Conclusions: This study shows that GBP + B1/B12 equally reduces pain intensity as PGB, although this reduction was obtained with lower doses (300 - 1800 mg) to those reported in clinical trial with GBP as monotherapy; likewise, a reduced occurrence of dizziness, vertigo and somnolence was also observed. These results are showing that the combination of vitamins B plus gabapentin is as effective as pregabalin in the painful diabetic neuropathy treatment; however, the combination improves the safety profile.