A Real-world Pilot Observational Study of Neuropathic Pain Medications in Older Adult Patients in North India

Aims: This pilot study aimed to make head-to-head comparisons of multiple classes of drugs used in the management of neuropathic pain in North Indian older adult patients presenting to the geriatric clinic of a tertiary medical institution. Background: Chronic neuropathic pain is a condition affecting nearly one third of older adults. There is paucity of data on head-to-head comparisons of drugs used in neuropathic pain in older adults. Real world studies may be a useful tool to study diverse neuropathic pain medications in this population. Objectives: The study objective was to measure NPRS (numeric pain rating scale), GDS (geriatric depression scale), IADL (instrumental activities of daily living), HMSE (Hindi mental state examination) scores at baseline, and 4- and 12-week follow-ups in all older adult patients receiving neuropathic pain medications. Methods: A prospective observational study was conducted involving older adult patients ≥ 50 years of age with painful peripheral neuropathy of any etiology (n=60; mean age 63±8.4 years). The patients received either gabapentin, pregabalin, duloxetine, amitriptyline, or methyl- cobalamin complex. NPRS, GDS, IADL, and HMSE scores were measured at baseline and post-therapy. Results: All groups except amitriptyline showed statistically significant improvement in NPRS at 4 weeks and 12 weeks compared to baseline. 30% response rate at 4 weeks was maximum for pregabalin (72%) and 50% response rate at 12 weeks was maximum for gabapentin (58%). Numerically maximum improvement in depression was seen with duloxetine. There was no statistically significant difference in the measured parameters between the drug groups across time. Mean daily dose was 172 mg (gabapentin group), 75 mg (pregabalin group) and 20 mg (duloxetine group). The adverse drug reaction rate was 10.5%. Conclusion: All drug groups showed beneficial effects on neuropathic pain at much lower doses than those described in the literature. The effectiveness at these low doses and the lower rates of adverse effects sets the foundation for larger studies in the future in diverse ethnic and aged populations.