Randomized, Double-blind, Placebo-controlled Phase III Trial of Duloxetine Monotherapy in Japanese Patients With Chronic Low Back Pain.
METHODS
A 14-week, randomized, double-blind, multicenter, placebo-controlled study of Japanese patients with chronic low back pain (CLBP) who were randomized to either duloxetine 60 mg once daily or placebo.


OBJECTIVE
This study aimed to assess the efficacy and safety of duloxetine monotherapy in Japanese patients with CLBP.


BACKGROUND
In Japan, duloxetine is approved for the treatment of depression, diabetic neuropathic pain, and pain associated with fibromyalgia; however, no clinical study of duloxetine has been conducted for CLBP.


METHODS
The primary efficacy measure was the change in the Brief Pain Inventory (BPI) average pain score from baseline to Week 14. Secondary efficacy measures included BPI pain (worst pain, least pain, pain right now), Patient's Global Impression of Improvement, Clinical Global Impressions of Severity, and Roland-Morris Disability Questionnaire, among other measures, and safety and tolerability.


RESULTS
In total, 458 patients were randomized to receive either duloxetine (n = 232) or placebo (n = 226). The BPI average pain score improved significantly in the duloxetine group compared with that in the placebo group at Week 14 [-2.43 ± 0.11 vs. -1.96 ± 0.11, respectively; between-group difference (95% confidence interval), - 0.46 [-0.77 to-0.16]; P = 0.0026]. The duloxetine group showed significant improvement in many secondary measures compared with the placebo group, including BPI pain (least pain, pain right now) (between-group difference: -1.69 ± 0.10, P = 0.0009; -2.42 ± 0.12, P P = 0.0230, respectively), Patient's Global Impression of Improvement (2.46 ± 0.07, P = 0.0026), Clinical Global Impressions of Severity (-1.46 ± 0.06, P = 0.0019), and Roland-Morris Disability Questionnaire (-3.86 ± 0.22, P = 0.0439). Adverse events occurring at a significantly higher incidence in the duloxetine group were somnolence, constipation, nausea, dizziness, and dry mouth, most of which were mild or moderate in severity and were resolved or improved.


CONCLUSIONS
Duloxetine 60 mg was effective and well tolerated in Japanese CLBP patients.


METHODS
2.
Department of Orthopedic Surgery, Fukushima Medical University, Fukushima, Japan.
Shinichi
S
Konno
Shionogi and Co. Ltd, Osaka, Japan.
Natsuko
N
Oda
Shionogi and Co. Ltd, Osaka, Japan.
Toshimitsu
T
Ochiai
Medicines Development Unit, Medical Science, Eli Lilly Japan K.K., Kobe, Japan.
Levent
L
Alev
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059350:Chronic Pain / Q000188:drug therapy*; D004311:Double-Blind Method; D000068736:Duloxetine Hydrochloride / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D005356:Fibromyalgia / Q000188:drug therapy*; D006801:Humans; D007564:Japan; D017116:Low Back Pain / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods; D010919:Placebos / Q000627:therapeutic use; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
D010919:Placebos; D000068736:Duloxetine Hydrochloride