Efficacy and safety of duloxetine in patients with chronic low back pain.
Author(s): Skljarevski V, Desaiah D, Liu-Seifert H, Zhang Q, Chappell AS, Detke MJ, Iyengar
S, Atkinson JH, Backonja M.
Affiliation(s): Lilly Research Laboratories, Indianapolis, IN, USA. vladimir@lilly.com
Publication date & source: 2010, Spine (Phila Pa 1976). , 35(13):E578-85
STUDY DESIGN: This was a randomized, double-blind, placebo-controlled clinical
trial.
OBJECTIVE: To assess the efficacy and safety of duloxetine in the treatment of
chronic low back pain (CLBP).
SUMMARY OF BACKGROUND DATA: Imbalance of serotonin and norepinephrine within
modulatory pain pathways has been implicated in the development and maintenance
of chronic pain. Duloxetine, a selective reuptake inhibitor of serotonin and
norepinephrine, has demonstrated clinical efficacy in 3 distinct chronic pain
conditions: diabetic peripheral neuropathic pain, fibromyalgia, and chronic pain
because of osteoarthritis.
METHODS: In this randomized double-blind trial, adult nondepressed patients with
a non-neuropathic CLBP and a weekly mean of the 24-hour average pain score>or=4
at baseline (0-10 scale) were treated with either duloxetine or placebo for 13
weeks. The dose of duloxetine during first 7 weeks was 60 mg once daily. At week
7, patients reporting<30% pain reduction had their dose increased to 120 mg. The
primary outcome measure was the Brief Pain Inventory (BPI) 24-hour average pain
rating. Secondary measures included Roland-Morris Disability Questionnaire-24;
Patient's Global Impressions of Improvement; Clinical Global Impressions-Severity
(CGI-S); BPI-Severity and -Interference (BPI-I); and weekly means of the 24-hour
average pain, night pain, and worst pain scores from patient diaries.
Quality-of-life, safety, and tolerability outcomes were also assessed.
RESULTS: Compared with placebo-treated patients (least-squares mean change of
-1.50), patients on duloxetine (least-squares mean change of -2.32) had a
significantly greater reduction in the BPI 24-hour average pain from baseline to
endpoint (P=0.004 at week 13). Additionally, the duloxetine group significantly
improved on Patient's Global Impressions of Improvement; Roland-Morris Disability
Questionnaire-24; BPI-Severity and average BPI-Interference; weekly mean of the
24-hour average pain, night pain, and worst pain. Significantly more patients in
the duloxetine group (13.9%) compared with placebo (5.8%) discontinued because of
adverse events (P=0.047). The most common treatment-emergent adverse events in
the duloxetine group included nausea, dry mouth, fatigue, diarrhea,
hyperhidrosis, dizziness, and constipation.
CONCLUSION: Duloxetine significantly reduced pain and improved functioning in
patients with CLBP. The safety and tolerability were similar to those reported in
earlier studies.
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