Efficacy of duloxetine for multisite pain in patients with knee pain due to osteoarthritis: An exploratory post hoc analysis of a Japanese phase 3 randomized study
Naohiro Itoh, Toshinaga Tsuji, Mitsuhiro Ishida, Toshimitsu Ochiai, Shinichi Konno, Yuji Uchio, Naohiro Itoh, Toshinaga Tsuji, Mitsuhiro Ishida, Toshimitsu Ochiai, Shinichi Konno, Yuji Uchio
Abstract
Background: Central sensitization, including dysfunction of descending inhibitory pain pathways, may contribute to multisite pain in patients with chronic musculoskeletal conditions. Duloxetine is a centrally acting analgesic that effectively reduces pain in patients with knee osteoarthritis. Here we assessed the efficacy of duloxetine (60 mg/day) in Japanese patients (N = 353) with pain due to knee osteoarthritis based on the number of painful body sites, determined using the Michigan Body Map.
Methods: Post hoc analysis of a phase 3, randomized, placebo-controlled trial (ClinicalTrials.gov; NCT02248480).
Results: At Week 14, the change from baseline in Brief Pain Inventory-Severity average pain score ("pain reduction") was significantly greater with duloxetine compared with placebo in patients with 3, 4, or ≥5 painful sites, but not in patients with 1 or 2 painful sites. In patients with ≥3 painful sites (57% of patients), pain reduction was significantly greater with duloxetine (n = 100) compared with placebo (n = 101) throughout the study (least squares mean change from baseline to Week 14: -2.68 vs -1.68). Greater pain reduction with duloxetine (n = 77) than placebo (n = 75) also occurred in patients with ≤2 painful sites, although the between-group difference was significant only at Week 4.
Conclusions: These results are consistent with duloxetine enhancing the activity of descending inhibitory pain pathways that are dysfunctional in patients with central sensitization and multisite pain. In addition, these results suggest that duloxetine may be an effective choice of analgesic for patients with knee osteoarthritis and multisite pain.
Conflict of interest statement
Declaration of Competing Interest NI, TT, MI, and TO are full-time employees and minor stockholders in Shionogi & Co., Ltd. TT is also a stockholder in Takeda Pharmaceutical Company Limited. YU has received honoraria/consulting fees, travel support, fees for participation in review activities, fees for writing assistance, medicine, equipment, and administrative support, and/or grants from Shionogi & Co., Ltd. (this study); Eli Lilly Japan K.K. (this study); Astellas Pharma Inc.; Asahi Kasei Pharma Corporation; Chugai Pharmaceutical Co., Ltd.; Daiichi Sankyo Co., Ltd.; Kaken Pharmaceutical Co., Ltd.; Nippon Zoki Pharmaceutical Co., Ltd.; Seikagaku Corporation; Taisho Toyama Pharmaceutical Co., Ltd; Teijin Pharma Limited; Pfizer Japan Inc.; Japan Tissue Engineering Co., Ltd.; Ayumi Pharmaceutical Corporation; Hisamitsu Pharmaceutical Co., Inc.; Eisai Co., Ltd.; Meira Co.; Stryker Japan K.K.; and Takeda Pharmaceutical Company Limited. SK has received grants, honoraria, reviewing fees, payment for lectures, fees for writing assistance, medicines, equipment, and/or administrative support from Shionogi & Co., Ltd. (this study); Eli Lilly Japan K.K. (this study); Asahi Kasei Pharma Corporation; Eisai Co., Ltd.; Ono Pharmaceutical Co., Ltd.; Kaken Pharmaceutical Co., Ltd.; Johnson & Johnson K.K.; Daiichi Sankyo Co., Ltd.; Taisho Toyama Pharmaceutical Co., Ltd.; Takeda Pharmaceutical Company Limited; Nippon Zoki Pharmaceutical Co., Ltd.; Hisamitsu Pharmaceutical Co., Inc.; Pfizer Japan Inc.; Janssen Pharmaceutical K.K.; Ayumi Pharmaceutical Corporation; Taiho Pharmaceutical Co., Ltd.; Chugai Pharmaceutical Co., Ltd.; Teijin Pharma Limited; Astellas Pharma Inc.; Nippon Shinyaku Co., Ltd.; Stryker Japan K.K.; Tsumura & Co.; and Otsuka Pharmaceutical Co., Ltd.
Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.
Source: PubMed