A PROSPECTIVE, RANDOMISED, COMPARATIVE STUDY OF EFFICACY AND SAFETY OF PREGABALIN, DULOXETINE AND AMITRIPTYLINE IN PATIENTS OF PAINFUL DIABETIC NEUROPATHY IN A TERTIARY CARE TEACHING HOSPITAL IN RURAL BENGAL

Painful Diabetic Polyneuropathy (DPN) is one of the commonest microvascular complications, affecting nearly 26% of diabetic patients. Amitriptyline, Duloxetine and Pregabalin are all approved internationally for managing neuropathic pain apart from strict glycaemic control. OBJECTIVES To compare efficacy and safety of Pregabalin, Duloxetine and Amitriptyline in reducing neuropathic pain as well as improving quality of sleep among patients of DPN. METHODOLOGY We performed an open label, prospective, randomized, 12 week, observational study, at the Neurology OPD at B. S. Medical College. A total of 93 DM patients with baseline pain score >4 in numeric pain rating scale were enrolled and randomized to receive Pregabalin (n=31), Duloxetine (n=31) and Amitriptyline (n=31). Severity of neuropathic pain as assessed by NPSI score was recorded at baseline after 4 weeks and 12 weeks interval along with measurement of glycaemic control. We also measured improvement in sleep quality using PSQI score at all visits. Safety assessment was done by comparing treatment emergent adverse effects and by comparing laboratory parameters. RESULT Final assessment was done in 87 patients excluding 6 dropouts. Status of glycaemic control among all three groups was not significantly different. A significant decrease in mean pain score was seen in all three groups across time (p<0.05), but no significant difference was noted between the groups. The decrease in pain severity occurred more slowly during first 4 weeks with Amitriptyline than other two drugs. Sleep quality improved in all three groups in the first 4 weeks significantly, but no further significant improvement happened at 12 weeks in any groups. ADRs were mostly mild, occurring in 24.1% of cases, with highest incidence in patients receiving Amitriptyline. CONCLUSION All these three drugs showed similar efficacy in reducing pain in diabetic polyneuropathy as well as improving the sleep quality. Amitriptyline, relatively inexpensive, may be preferred over the other two in this rural financially disadvantaged population. A large, blinded, multi-centric trial is being planned to find out superiority in safety or efficacy of these drugs.