Efficacy and tolerability of carbamazepine for the treatment of painful diabetic neuropathy in adults: a 12-week, open-label, multicenter study

Abstract
Anticonvulsants are increasingly being used in the symptomatic management of several neuropathic pain disorders. The present observational study was designed to evaluate the efficacy, tolerability, and quality of life (QoL) of carbamazepine use for 12 weeks in patients with painful diabetic neuropathy, in Pakistan. This was a 12-week, multicenter, open-label, uncontrolled trial in adult type 2 diabetic patients (aged 18-65 years) suffering from clinically confirmed neuropathic pain (Douleur Neuropathique en 4 [DN4] score ≥4). Change in neuropathic pain at week 12 compared with baseline was assessed using the Brief Pain Inventory Scale-Short Form (pain severity score and pain interference score). QoL was determined by the American Chronic Pain Association QoL scale. Safety was assessed based on patient reported adverse events (AEs) and serious AEs. Of the total 500 screened patients, 452 enrolled and completed the study. The mean (± standard deviation [SD]) pain interference score decreased from 4.5±2.0 at baseline to 3.1±1.9 at week 12 (P<0.001). The mean (± SD) pain severity score decreased from 5.8±2.0 at baseline to 3.6±2.2 at week 12 (P<0.001). There was a decrease of ≥30% in the pain severity score between visits. The mean (± SD) QoL scale score improved from 5.9±1.6 at baseline to 8.0±1.7 at week 12. A total of ten (2.2%) patients reported AEs during the study period. No patient discontinued the study due to AEs. In this real-life experience study, carbamazepine, when prescribed for 12 weeks to adult diabetic patients suffering from neuropathic pain, showed pain-relief effect, with reduced mean pain severity and mean pain interference scores and with improved QoL and good tolerability profile.