Efficacy of Duloxetine in the Management of Diabetic Neuropathy: A Prospective Observational Cohort Study

TL;DR

This study shows that duloxetine effectively reduces pain and improves nerve function in diabetic neuropathy patients over eight weeks.

Contribution

The study provides empirical evidence on duloxetine's efficacy and safety in managing diabetic neuropathy in a real-world clinical setting.

Findings

Duloxetine significantly reduced pain scores on the Visual Analog Scale over eight weeks.

Nerve conduction velocity improved significantly for both median and peroneal nerves.

Adverse effects were mild and manageable, with no serious complications reported.

Abstract

Background

Diabetic neuropathy (DN) is a prevalent complication of diabetes mellitus (DM), often leading to chronic pain and impaired quality of life. Duloxetine, a serotonin-norepinephrine reuptake inhibitor (SNRI), has been widely studied for its potential role in alleviating neuropathic pain.

Objective

This study aimed to evaluate the efficacy and safety of duloxetine in the management of DN.

Methods

A cross-sectional study was conducted in the Medicine Department of Sandeman Provincial Hospital, Quetta, from November 2022 to October 2023. A total of 113 patients aged between 25 and 65 years with clinically diagnosed DN were included. Patients received duloxetine, starting at 20 mg daily, with gradual dose escalation based on tolerance. Pain severity was assessed using the Visual Analog Scale (VAS), and nerve conduction studies (NCS) were performed at baseline, four weeks, and eight weeks post-treatment. Biochemical parameters, including fasting blood glucose (FBG), postprandial blood glucose (PPBS), and HbA1c levels, were measured at baseline. Adverse effects were recorded at each follow-up visit. Statistical analyses were conducted using IBM SPSS Statistics for Windows, Version 26.0 (Released 2019; IBM Corp., Armonk, NY, United States), with paired t-tests for continuous variables and chi-square tests for categorical variables. A p < 0.05 was considered statistically significant.

Results

The mean age of participants was 52.7 ± 8.1 years, with a mean diabetes duration of 6.3 ± 2.1 years. Eighty patients (70.8%) had poor glycemic control, with an HbA1c level > 6.5%. The mean baseline pain score on the VAS was 7.6 ± 1.1, which significantly reduced to 4.3 ± 0.9 at four weeks and 2.5 ± 0.8 at eight weeks (p < 0.001). NCS showed significant improvements in median and peroneal nerve conduction velocity, with mean median nerve conduction velocity increasing from 48.5 ± 6.2 m/s at baseline to 51.1 ± 5.9 m/s at four weeks and 54.3 ± 5.8 m/s at eight weeks (p < 0.001). Peroneal nerve conduction velocity also improved from baseline to follow-up at four weeks and eight weeks (p < 0.001). Adverse effects were reported in 32 (28.3%) patients, with nausea (12, 10.6%), dizziness (8, 7.1%), and somnolence (7, 6.2%) being the most common.

Conclusion

Duloxetine demonstrated significant efficacy in reducing neuropathic pain and improving nerve conduction parameters in patients with DN over an eight-week period. The drug was well tolerated, with mild and manageable adverse effects. These findings support the use of duloxetine as an effective and safe therapeutic option for managing DN.