A study published in Pain Medicine found that duloxetine was effective for treating moderate to severe central poststroke pain (CPSP).
As “[c]entral poststroke pain is often neglected and imposes a great burden on the patients and impairs their quality of life,” a team of investigators conducted a single center, randomized, double-blind, placebo-controlled study to determine the effectiveness of duloxetine for decreasing pain among patients with CPSP.
Patients (N=82) presenting with moderate to severe pain following a hemorrhagic or ischemic stroke and who were found to have a unilateral brain lesion detected by computed tomography or magnetic resonance imaging at the Banaras Hindu University in India between 2021 and 2022 were recruited to participate in this study. The patients were randomly assigned in a 1:1 ratio to receive 1 or two 30-mg tablets of flexible-dose duloxetine (n=41) or placebo (n=41) daily for 4 weeks. All patients started taking 1 tablet per day. At 2 weeks, patients who did not achieve a 2-point or greater decrease in numeric rating scale (NRS) pain scores were advised to take 2 tablets per day. Safety and efficacy were evaluated at 4 weeks.
The mean ages of patients in the intervention and control arms were 58.90±10.33 and 52.66±8.48 years, 26.8% and 19.5% had diabetes (P =.01), and 85.4% and 90.2% had sensory impairment (P =.02). Participants in both groups had been experiencing pain for a median of 60 days, and onset of pain among patients in the intervention and control arms occurred 30 (IQR, 10-360) and 45 (IQR, 7-224) days after stroke (P =.003), respectively.
At the 2-week follow-up, 22% of patients in the duloxetine group and 61% of patients in the placebo group had their dose increased due to inefficacy (P =.042). Among those receiving duloxetine, 78.1% responded to the 30 mg/d dosage, and 19.5% did not respond to the 60 mg/d dosage.
Participants in the duloxetine and placebo groups reported similar NRS (mean, 6.51 vs 6.37), Short Form McGill Pain Questionnaire-2 (SFMPQ-2; mean, 19.53 vs 20.29), and Pain Disability Index (PDI; mean, 42.95 vs 42.05) scores at baseline, respectively. At the end of 4 weeks of treatment, participants in the duloxetine cohort reported significantly lower NRS (mean, 3.02 vs 4.40; P =.002), SFMPQ-2 (mean, 8.85 vs 13.29; P =.032), and PDI (mean, 24.18 vs 30.05; P =.005) scores compared with those receiving placebo, respectively. In addition, duloxetine was also favored over placebo with regard to Patient Global Impression of Change scores (mean, 5.15 vs 3.89; P <.001).
The most common adverse events reported by duloxetine recipients were dizziness (n=7), somnolence (n=6), nausea (n=6), and vomiting (n=4).
This study found evidence to support the use of duloxetine for the treatment of moderate to severe CPSP. Additional, longer-term studies are needed to evaluate long-term safety and efficacy of duloxetine for the treatment of CPSP.
Mahesh B, Singh VK, Pathak A, et al. Efficacy of duloxetine in patients with central post-stroke pain: a randomized double blind placebo controlled trial. Pain Med. Published online November 21, 2022. doi:10.1093/pm/pnac182