Use of olanzapine in anorexia nervosa.

Sir: Barbarich et al. 1 report the potential benefits of olanza-pine in treating anorexia nervosa. I disagree with their results and conclusions for the following reasons. The study's small sample size of 17 patients, 12 of whom completed the study, could result in a type II error. That 71% of patients completed the study is not " noteworthy, " as the authors claim. Powers and colleagues 2 published a 10-week trial of olanzapine treatment of anorexia nervosa with a 64% completion rate. Fassino and colleagues 3 reported a 75% completion rate in a randomized, placebo-controlled study of citalopram treatment of anorexia nervosa. Curiously, for the 3 patients who terminated the study against medical advice, Barbarich et al. did not explain their reasons for doing so. It is reasonable to conclude that weight gain resulting from olanzapine treatment was a factor. By definition , patients with anorexia nervosa have a morbid fear of weight gain and obesity, and olanzapine-induced weight gain makes this medication a poor treatment option. Woodside and colleagues 4 found that concerns about weight gain among ano-rexia nervosa patients were a predictor in their premature termination from inpatient programs specializing in treating eating disorder. Proposed mechanisms of olanzapine-induced weight gain include increased food intake, decreased motor activity, and increased ratio of weight gain:weight of food consumed. 5 In fact, olanzapine may not be a suitable medication for treating patients with anorexia nervosa due to its high incidence of weight gain. Studies reporting weight gain during olanzapine use can be divided into short-term (less than 2 months) and long-term (3 months or more). Numerous short-term studies report significant weight gain during olanzapine treatment. 2,6,7 Patel and colleagues 6 found that patients treated with olanzapine gained an average of 3.8 kg. A 10-week, single-blind study of children aged 7 to 13 years with Tourette's syndrome found that olanzapine's most common side effect was weight gain (mean = 12.0 lb). 7 An open-label, 10-week study of olanzapine treatment of anorexia nervosa found an average 8.75-lb weight gain. 2 Regarding long-term studies, Eli Lilly's package insert for Zyprexa 8 disclosed that, during treatment lasting a median of 238 days, 56% of patients gained more than 7% of their baseline weight, with an average weight gain of 5.4 kg. Haberfellner and Rittmannsberger 9 found that 67% of olanzapine-treated patients gained more than 7% of baseline initial body weight with a mean weight gain …