Introduction: Duloxetine hydrochloride is a dual reuptake inhibitor of both serotonin and
norepinephrine. In the present open-label study, the safety of duloxetine at a fixed-dose of
60 mg twice daily (BID) for up to 52 weeks was evaluated and compared to routine care in
the therapy of patients diagnosed with diabetic peripheral neuropathic pain (DPNP).
Methods: Patients who completed a 13-week, double-blind, duloxetine and placebo acute
therapy period were rerandomly assigned in a 2:1 ratio to therapy with duloxetine 60 mg BID
(N = 161) or routine care (N = 76) for an additional 52 weeks. Routine care consisted primarily
of gabapentin, amitriptyline, and venlafaxine. The study included male or female outpatients
18 years of age or older with a diagnosis of DPNP caused by type 1 or type 2 diabetes.
Results: A higher percentage of routine care-treated patients experienced 1 or more serious
adverse events. No statistically significant therapy-group difference was observed in the overall
incidence of treatment-emergent adverse events (TEAEs). The TEAEs reported by 10% or
more of duloxetine 60 mg BID-treated patients were nausea, and by the routine care-treated
patients were peripheral edema, pain in the extremity, somnolence, and dizziness. Duloxetine
did not appear to adversely affect glycemic control, lipid profiles, nerve function, or the
course of DPNP. There were no statistically significant therapy-group differences observed
in the 36-item Short-Form Health Survey subscales or in the EuroQol 5-Dimension Questionnaire.
Conclusions: In this study, duloxetine was safe and well tolerated compared to routine care
in the long-term management of patients with DPNP.
