SAN ANTONIO – Teenagers with anorexia nervosa gained weight faster when taking the atypical antipsychotic drug olanzapine, according to results from an open-label study presented at the annual meeting of the American Academy of Child and Adolescent Psychiatry.
Olanzapine is used frequently off-label in the treatment of anorexia, said Dr. Wendy Spettigue of the Children’s Hospital of Eastern Ontario in Ottawa. In addition to the known metabolic effects of the drug, in clinical use “it seems to decrease eating disorder thoughts and preoccupations, and with that, resistance to taking the nutrition.” However, she noted, “there’s been little to date in terms of research in adolescents.”
One previous placebo-controlled pilot study in adolescent girls (n =20) found no differences in rate or amount of weight gain between olanzapine-treated and placebo groups (J Child Adolesc Psychopharmacol. 2011;21:207-12).
Dr. Spettigue and colleagues’ study, the largest to date to look at olanzapine in this patient group, compared low-weight patients who received standard care plus olanzapine (n = 22) to those who received standard care only (n = 10), which included nutritional support and therapy. All but three patients were girls, 85% were inpatients, and median age at baseline was 15.5 years. The mean percentage of ideal body weight was 77% and 78%, respectively, for the two groups. Doses of olanzapine ranged from 2.5 mg to 7.5 mg, with most patients on 5 mg at bedtime.
Both groups showed significant weight gains across the 6-week study period. However, the intervention group saw a significantly greater rate of increase after week 3, with the olanzapine group gaining a mean 1.53 kg between weeks 3 and 4 (vs. 0.81 in the comparison group) and 2.64 kg between weeks 4 and 6 of treatment (vs. 1.51; P = .012).
Patients in the study “were told that whether they take the medication or not they need to get to their healthy weight. We taper them off once they have reached their healthy weight, and many of them end up on SSRIs alongside family therapy as part of ongoing treatment,” Dr. Spettigue said.
Secondary outcomes in the study included the Multidimensional Anxiety Scale for Children, the Eating Disorder Examination Questionnaire, and the Children’s Depression Inventory. Both the intervention and comparison groups, which were well matched on these measures at baseline, saw decreases for anxiety (P = .27), depression (P less than .1), and eating disorders (P = .04). Between-group differences did not reach statistical significance.
The researchers did note elevations in lipid profiles in about a third of the olanzapine-treated patients. Dr. Spettigue said she did not find this worrisome in this patient group, who were only on the medication for a short time, but she stressed that medical monitoring was extremely important.
The W. Garfield Weston Foundation funded the study. The investigators reported no conflicts of interest.