Atomoxetine for weight reduction in obese women: a preliminary randomised controlled trial

Atomoxetine is a potent central norepinephrine uptake inhibitor, currently marketed for treatment of attention-deficit/hyperactivity disorder (ADHD). With the understanding that noradrenergic agents could be useful in assisting obese individuals to lose weight, we conducted this preliminary study to evaluate short-term efficacy and safety of atomoxetine in obese adults.

At 12-week randomised, double-blind, placebo-controlled trial, conducted at Duke University Medical Centre, USA, from May 2004 to December 2004.

A total of 30 obese women (mean (s.e.) body mass index of 36.1 (0.6) kg/m2).

Participants were randomly assigned to receive atomoxetine (n=15) or placebo (n=15). All participants were advised to follow a balanced hypocaloric diet (500 kcal/day deficit). Atomoxetine therapy was started at 25 mg/day orally, with gradual increase to 100 mg/day over 1 week. Placebo dosing was identical.

Body weight in kilograms was the primary outcome measure. Other measurements included waist circumference, blood pressure and heart rate, fasting plasma glucose and lipids, and depressive symptoms.

Last-observation-carried-forward analysis of the available data for participants who had completed at least one post-randomisation assessment, demonstrated that the atomoxetine group (n=12) lost more body weight over the 12-week period than the placebo (n=14) group (mean (s.e.) -3.6 (1.0) kg (-3.7% loss) vs 0.1 (0.4) kg (0.2% gain); F (4,96)=11.9; P<0.0001). Three participants in the atomoxetine group and none in the placebo group lost >or=5% weight. Side effects were minimal.

Atomoxetine demonstrated modest short-term weight loss efficacy relative to placebo in this preliminary study of obese women.