ISTANBUL, TURKEY – Early marked reduction in pain in response to duloxetine proved to be the strongest predictor of significant long-term improvement in depressive symptoms in depressed subjects in the German PADRE study.
A 50% or greater improvement in self-gauged overall pain symptoms on a visual analog scale (VAS) after 4 weeks on the selective norepinephrine reuptake inhibitor was associated with a threefold greater likelihood of achieving at least a 50% decrease on the clinician-rated Inventory for Depressive Symptomatology (IDS) scale at 6 months, the primary study end point, Dr. Michael Linden said at the annual congress of the European College of Neuropsychopharmacology.
PADRE was a prospective observational study in which 4,517 adult outpatients with a depressive episode received treatment with duloxetine (Cymbalta) at 693 centers in Germany. Lilly Deutschland and Boehringer Ingelheim sponsored the study. The mean age of participants was 52 years, and 72% were women.
The mean baseline score on the clinician-rated IDS was 40 on the 0–84 scale. Eighty percent of subjects had moderate to severe painful symptoms at baseline (VAS score of greater than 30 out of a possible 100). During the 6-month study, 26.5% of subjects dropped out.
The mean VAS pain score in the overall study population improved from 55 at baseline to 31 at 6 months. Forty-eight percent of patients reported at least a 50% reduction in pain on the VAS after 4 weeks of treatment, a clinically significant improvement. Nearly two-thirds of these early pain responders experienced remission of their depression by 6 months as defined by an Inventory for IDS score of 12 or less; this remission rate was twice that of patients who did not achieve at least a 50% decrease in pain at 4 weeks, noted Dr. Linden of Charit University Hospital, Berlin.
The secondary end point was the change over 6 months in the KUSTA, a 100-point German-language depression scale encompassing mood, activity, sleep, and tension/relaxation. The mean KUSTA improved from a baseline of 25 to 58 points at 6 months in those who did not show a significant pain response by 4 weeks, and by an additional 13.3 points in those who did.
Seventeen percent of PADRE participants reported one or more treatment-emergent adverse events, most commonly mild nausea and other GI side effects, hyperhidrosis, vertigo, and headache. There was no weight gain during the 6 months of therapy.