Background: Olanzapine is used for treatment of psychiatric conditions but causes substantial weight gain. This study assessed safety, efficacy, and changes in metabolic cytokines associated with olanzapine administration in patients with cachexia due to advanced cancer.
Methods: Patients with cancer-related cachexia were treated with olanzapine (doses ranging from 2.5 to 20 mg daily by mouth). Patients also received anti-neoplastic treatments. Serum samples were collected at baseline and after weeks 1, 2, 4, and 8 for analysis of levels of leptin, growth hormone, ghrelin, and interleukin-6 (IL-6).
Results: Of the 39 participants, 31 were evaluable for weight change (N = 6 excluded for new ascites; N = 2, incomplete body weight of data). Toxicities related to olanzapine were somnolence (n = 1), pancreatitis (n = 1), extrapyramidal symptoms (n = 1), and nausea/vomiting (n = 1) (all grade 2). The recommended dose of Olanzapine is 20 mg PO daily for cancer patients (same as FDA approved dose for psychiatric conditions). Samples from 29 patients were eligible for analysis of serum cytokine levels. Mean values of leptin, ghrelin, and growth hormone did not change on treatment, though IL-6 levels increased, perhaps due to tumor progression. There was no association between changes in cytokines and weight. The mean change in slope of weight loss before versus after therapy was 0.24 (95 % CI, -0.08, 0.56; p = 0.13) indicating a trend, albeit not reaching statistical significance, toward attenuation of weight loss.
Conclusion: Changes in metabolic cytokines and body weight did not correlate. Treatment with olanzapine had only a modest effect in altering the trajectory of weight loss.