Safety and efficacy of duloxetine versus gabapentin in painful diabetic polyneuropathy

Abstract

To evaluate safety and efficacy of Gabapentin and Duloxetine in patients with painful diabetic neuropathy.This is a prospective randomized double blinded parallel group study done for a period of 12 weeks. Total of 60 patients were enrolled and randomly allocated to two groups with 30 patients each, group A received Duloxetine 30 mg twice daily and group B received Gabapentin 300mg twice daily and followed every 2 weeks. Patients of age 35 to 60 years with painful diabetic peripheral polyneuropathy are included in the study. Primary objective is improvement in pain assessed by NPRS; Secondary objective is improvement in sleep and clinical condition of the patient, assessed by Sleep Interference Score and Clinical Global Impression of Change (CGIC). Assessment was done at beginning and at four, eight and twelve weeks. Data was analysed using SPSS 12.0 version.Numerical pain rating scores and daily sleep interference scores were reduced significantly with course of treatment within both groups (p = <0.05 in both groups), but there was no significant difference observed between two groups at baseline, 4th week, 8th week and 12th week. There is significant reduction in CGIC severity scores with course of treatment within both groups (p = <0.05 in both groups), but there was no significant difference observed between groups at baseline and at end of treatment. Common adverse events seen are nausea, dry mouth, dizziness, somnolence and constipation in both groups. There is high incidence of nausea and dry mouth with Duloxetine when compared to Gabapentin.Monotherapy with either Duloxetine or Gabapentin was equally effective at 12 weeks treatment with minor side effects. In addition, Gabapentin showed fewer side effects. It can be concluded that for preventing side effects, Gabapentin can be used. Further large head to- head comparator and combination trials are required.