Taken once daily, Cymbalta (duloxetine HCI) can significantly reduce pain severity in patients with knee pain caused by osteoarthritis, according to the results of a double-blind, placebo-controlled clinical trial. Results of the study conducted at research sites in five countries were presented at the annual meeting of the American Academy of Pain Medicine.

Patients were randomized to duloxetine (n = 128) or placebo (n = 128) and stratified by whether or not they used nonsteroidal anti-inflammatory drugs. At week seven, 33 patients who showed suboptimal response to the 60-mg dose had their dose increased to 120 mg. At the end of the 13-week trial, 65% of duloxetine-treated patients experienced a clinically significant (at least 30%) improvement in pain, compared with 44% of placebo-treated patients.

The duloxetine-treated patients also showed improved physical function, as measured by the Western Ontario and McMaster Osteoarthritis Index. However, they did not show statistically significant improvements in mood, walking ability, sleep, or enjoyment of life, according to the Brief Pain Inventory Pain Inference scales.