RESUMO
OBJECTIVES: Painful diabetic neuropathy (PDN) is highly prevalent and annoyingly in patients with diabetes. The aim of this study was to investigate the effects of oral N-acetylcysteine (NAC) compared to pregabalin in PDN. METHODS: One hundred two eligible patients with type 2 diabetes and PDN were randomly recievied pregabalin (150 mg/day) or N-Acetylcysteine (NAC) (600 mg/ twice a day) for 8 weeks. Mean pain score, Sleep interference score (SIS), Patient Global Impression of Change (PGIC), Clinical Global Impression of Change (CGIC), and also, serum levels of total antioxidant capacity (TAC), total thiol groups (TTG), catalase activity (CAT), nitric oxide (NO), and malondialdehyde (MDA) were assessed at baseline and at the end of the study. RESULTS: NAC was well tolerated in all patients. The decrease in mean pain scores and increase in SIS was similar between two groups. More improvement in PGIC and CGIC from the baseline was reported in NAC group. NAC, significantly, decreased serum levels of MDA, and NO, but increased TAC, TTG, and CAT. Pregabalin, significantly, decreased serum levels of MDA, and NO and increased TAC. DISCUSSION: NAC is efficacious in alleviate symptoms of PDN which is probably related to its antioxidant effects. TRIAL REGISTRATION: The research protocol received approval from the Ethics Committee of Hamadan University of Medical Sciences (IR.UMSHA.REC.1397.137). The trial registry URL and number in Iranian Registry of Clinical Trials (IRCT): https://www.irct.ir/trial/33313 , IRCT20180814040795N2 (Registration date: 2019-01-21, Retrospectively registered).