A randomized controlled trial of duloxetine in diabetic peripheral neuropathic pain.
BACKGROUND
Serotonin (5-HT) and norepinephrine (NE) are involved in pain modulation via descending inhibitory pathways in the brain and spinal cord.


OBJECTIVE
To assess the efficacy of duloxetine, a dual reuptake inhibitor of 5-HT and NE, on the reduction of pain severity, as well as secondary outcome measures in patients with diabetic peripheral neuropathic pain (DPNP).


METHODS
In this double-blind study, patients with DPNP and without comorbid depression were randomly assigned to treatment with duloxetine 60 mg once daily (QD), duloxetine 60 mg twice daily (BID), or placebo for 12 weeks. The primary outcome measure was the weekly mean score of 24-hour average pain severity on the 11-point Likert scale. Secondary measures and health outcome measures were also assessed.


RESULTS
Duloxetine 60 mg QD and 60 mg BID demonstrated improvement in the management of DPNP and showed rapid onset of action, with separation from placebo beginning at week 1 on the 24-hour average pain severity score. For all secondary measures for pain (except allodynia), mean changes showed an advantage of duloxetine over placebo, with no significant difference between 60 mg QD and 60 mg BID. Clinical Global Impression of Severity and Patient's Global Impression of Improvement evaluation demonstrated greater improvement on duloxetine- vs placebo-treated patients. Duloxetine showed no notable interference on diabetic controls, and both doses were safely administered.


CONCLUSIONS
This study confirms previous findings that duloxetine at 60 mg QD and 60 mg BID is effective and safe in the management of diabetic peripheral neuropathic pain.
Wernicke
J F
JF
Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN 46285, USA. jfwernicke@lilly.com
Pritchett
Y L
YL
D'Souza
D N
DN
Waninger
A
A
Tran
P
P
Iyengar
S
S
Raskin
J
J
D000082:Acetaminophen / Q000008:administration & dosage / Q000627:therapeutic use; D018759:Adrenergic Uptake Inhibitors / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D000368:Aged; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage / Q000627:therapeutic use; D003929:Diabetic Neuropathies / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D000068736:Duloxetine Hydrochloride; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009437:Neuralgia / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D009638:Norepinephrine / Q000378:metabolism*; D010146:Pain / Q000503:physiopathology; D010166:Palliative Care; D010523:Peripheral Nervous System Diseases / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D017367:Selective Serotonin Reuptake Inhibitors / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D012720:Severity of Illness Index; D013876:Thiophenes / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D016896:Treatment Outcome
D000082:Acetaminophen; D018759:Adrenergic Uptake Inhibitors; D018712:Analgesics, Non-Narcotic; D000068736:Duloxetine Hydrochloride; D009638:Norepinephrine; D017367:Selective Serotonin Reuptake Inhibitors; D013876:Thiophenes