Duloxetine for the management of diabetic peripheral neuropathic pain: Evaluation of functional outcomes

Objective. To assess the effectiveness of duloxetine, compared with placebo, on patient-reported health outcomes over a 12-week period, in the management of diabetic peripheral neuropathic pain (DPNP). Methods. The results were pooled from three 12-week multicenter, double-blind studies. In study 1 (N=457), patients with DPNP were randomly assigned to treatment with duloxetine 20 mg once daily (QD), 60 mg QD, 60 mg twice daily (BID), or placebo. In studies 2 (N=334) and 3 (N=348), patients with DPNP were randomly assigned to treatment with duloxetine 60 mg QD, 60 mg BID, or placebo. Patient-reported functional outcomes were measured by the Short Form 36 (SF-36), the interference portion of the Brief Pain Inventory (BPI), and EuroQol 5D Health Questionnaire (EQ-5D). Results for all functional outcomes from the intent-to-treat and completer populations are discussed. Results. In the SF-36 health survey and the BPI interference, duloxetine 60 mg QD and 60 mg BID were significantly superior to placebo in all the domains (P≤0.03). In the analysis of the EQ-5D, duloxetine 60 mg QD (P=0.004) and 60 mg BID (P<0.001) were significantly better than placebo on all items. Conclusions. Acute treatment with duloxetine was associated with significant improvement in functional outcomes in persons with DPNP.