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Olanzapine offers modest benefit in weight gain in adults with anorexia

Adult outpatients with anorexia nervosa who received olanzapine gained more weight each month on average than those who received placebo, study findings revealed.

“Efforts to develop effective pharmacological interventions for anorexia nervosa have been disappointing,” Evelyn Attia, MD, from the department of psychiatry, Columbia University Irving Medical Center, and the eating disorders research program, New York State Psychiatric Institute, and colleagues wrote.

“In recent decades, family-based methods of treatment have been developed and demonstrated to be effective for younger patients,” they continued. “However, among adult patients, anorexia nervosa is often refractory to psychological treatment and is associated with one of the highest mortality rates among all psychiatric disorders.”

Researchers conducted a randomized, double-blind, placebo-controlled trial of 152 adult outpatients with anorexia nervosa (96% women; mean BMI = 16.7) at multiple sites in North America to report the benefits of olanzapine compared with placebo.

After randomly assigning participants (1:1) to receive olanzapine or placebo, the investigators evaluated rate of change in body weight and rate of change in obsessionality via the Yale-Brown Obsessive-Compulsive Scale each week for 16 weeks. They also measured symptoms of eating disorder severity, depression and anxiety at baseline and 8 and 16 weeks after randomization. Initially, participants received 2.5 mg of medication each day for 2 weeks, then 5 mg per day for 2 weeks, followed by 10 mg per day at week 4.

Overall, 75 adults with anorexia nervosa received olanzapine and 77 received placebo, and many participants had co-occurring psychiatric diagnoses. Attia and colleagues found a statistically significant treatment-by-time interaction, which indicated a greater increase in BMI over time in the olanzapine group than the placebo group (0.259 vs. 0.095 per month).

Although the results showed no significant difference between treatment groups in change in the obsessionality total score of subscale scores, participants in the olanzapine group were three times more likely to be rated much or very much improved at week 16 (OR = 3.12; 95% CI, 0.83-11.78).

There were no significant differences in symptoms of eating disorder severity, depression or anxiety among those receiving olanzapine and those receiving placebo, the results showed. In addition, there were no significant differences in the frequency of abnormalities on blood tests that examined potential metabolic disturbances between treatment groups.

“The strengths of this study, including its relatively large sample size, the use of multiple sites, and the inclusion of patients with multiple other psychiatric disorders and on other psychotropic medications, suggest that the results are generalizable,” Attia and colleagues wrote. “Future studies should examine how best to combine olanzapine with other treatment interventions and assess longer-term outcomes.” – by Savannah Demko

Disclosure: The authors report no relevant financial disclosures.