Increased Food Intake and Energy Expenditure Following Administration of Olanzapine to Healthy Men

Pfizer Global Research and Development, New London, Connecticut, USA.
Obesity (Impact Factor: 4.39). 08/2010; 18(8):1646-51. DOI: 10.1038/oby.2010.6
Source: PubMed

ABSTRACT Atypical antipsychotic medications like olanzapine (OLZ) induce weight gain and increase the risk of diabetes in patients with schizophrenia. The goal of this study was to assess potential mechanisms of OLZ-induced weight gain and accompanying metabolic effects. Healthy, lean, male volunteers received OLZ and placebo (PBO) in a randomized, double-blind, crossover study. In periods 1 and 2, subjects received OLZ (5 mg for 3 days then OLZ 10 mg for 12 days) or matching PBO separated by a minimum 12-day washout. Twenty-four hour food intake (FI), resting energy expenditure (REE), activity level, metabolic markers, and insulin sensitivity (IS) were assessed. In total, 30 subjects were enrolled and 21 completed both periods. Mean age and BMI were 27 years (range: 18-49 years) and 22.6 +/- 2.2 kg/m(2), respectively. Relative to PBO, OLZ resulted in a 2.62 vs. 0.08 kg increase in body weight (P < 0.001) and 18% (P = 0.052 or 345 kcal) increase in FI. Excluding one subject with nausea and dizziness on the day of OLZ FI measurement, the increase in FI was 547 kcal, (P < 0.05). OLZ increased REE relative to PBO (113 kcal/day, P = 0.003). Significant increases in triglycerides, plasminogen activator inhibitor-I (PAI-I), leptin, and tumor necrosis factor-alpha (TNF-alpha) were observed. No significant differences in activity level or IS were observed. This study provides evidence that OLZ pharmacology drives the early increase in weight through increased FI, without evidence of decreased energy expenditure (EE), activity level, or short-term perturbations in IS.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Antipsychotic medications are associated with major metabolic changes that contribute to medical morbidity and a significantly shortened life span. The mechanisms for these changes provide us with a broader understanding of central nervous and peripheral organ-mediated metabolic regulation. This paper reviews an extensive literature regarding putative mechanisms for effects of antipsychotic medications on weight regulation and glucose homeostasis as well as potential inherent metabolic risks of schizophrenia itself. We present a model suggesting that peripheral antipsychotic targets play a critical role in drug-induced weight gain and diabetes. We propose that a better understanding of these mechanisms will be crucial to developing improved treatments for serious mental illnesses as well as providing potentially novel therapeutic targets of metabolic disorders including diabetes.
    Trends in Endocrinology and Metabolism 11/2014; 25(11). DOI:10.1016/j.tem.2014.07.004 · 8.87 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Second-generation antipsychotics (SGA) are associated with weight gain and metabolic alterations including hyperglycemia, dyslipidemia, hypertension and metabolic syndrome. These metabolic side effects increase cardiovascular risk and are related to medication non-compliance. Patients without previous exposure to these or other antipsychotic drugs (naive patients) seem to be more prone to develop these metabolic abnormalities. The mechanisms behind weight gain can be an increase in food intake and/or a decrease in energy expenditure. This review comprehensively examines the current knowledge on the impact of these drugs on food intake and energy expenditure. The influence of these drugs on appetite and food intake (total caloric intake and food sources) is reviewed as well as the evidence of abnormal eating behaviors. The studies evaluating the effect on resting energy expenditure are critically examined, taking into account the influence of body composition and previous exposure to antipsychotics (naive vs non-naive patients). Finally, the influence of these drugs on physical activity is also discussed. The knowledge of the mechanisms of weight gain in patients starting these drugs may be useful to further prompt research in this field and ameliorate the metabolic side effects associated with these treatments.European Journal of Clinical Nutrition advance online publication, 11 December 2013; doi:10.1038/ejcn.2013.253.
    European journal of clinical nutrition 12/2013; 68(2). DOI:10.1038/ejcn.2013.253 · 2.95 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The role of olanzapine added to a dopamine antagonist and benzodiazepine for the treatment of refractory chemotherapy-induced nausea and vomiting (CINV) is incompletely characterized in all levels of chemotherapy emetogenicity. This retrospective study evaluated the efficacy of the addition of olanzapine in adults experiencing refractory CINV stratified by chemotherapy emetogenicity. Thirty-three adults who experienced CINV refractory to guideline-recommended prophylaxis and breakthrough antiemetics (dopamine antagonists and benzodiazepines) and received at least one dose of olanzapine 5-10 mg per os were evaluated. Failure was defined as >5 emesis events in 24 h or more than 10 cumulative doses of rescue antiemetics following first olanzapine dose per treatment cycle. Post hoc analyses investigated variables impacting olanzapine efficacy. The addition of olanzapine demonstrated an overall success rate of 70 %. This success rate did not differ between chemotherapy regimens of high versus low-to-moderate emetogenicity (p = 0.79), prophylaxis with serotonin antagonist plus corticosteroid and aprepitant versus serotonin antagonist alone (p = 0.77), or age over 50 versus ≤50 years (p > 0.99). A trend toward greater benefit was seen in women (p = 0.08). The addition of olanzapine to a dopamine antagonist and benzodiazepine demonstrated high efficacy rates for refractory CINV irrespective of chemotherapy emetogenicity. The high success rates among all groups suggests that incomplete resolution of CINV with prophylactic serotonin antagonists and breakthrough dopamine antagonists plus benzodiazepine may benefit from the addition of olanzapine regardless of gender, degree of chemotherapy emetogenicity, number of prophylactic antiemetics, or age. The trend toward greater control of emesis in women merits further investigation.
    Journal of Cancer Research and Clinical Oncology 10/2013; DOI:10.1007/s00432-013-1540-z · 3.01 Impact Factor