The effect of reboxetine co-administration with olanzapine on metabolic and endocrine profile in schizophrenia patients

Rationale: We previously demonstrated that the addition of the selective norepinephrine reuptake inhibitor reboxetine attenuates olanzapine-induced weight gain. Using the same study sample, we also sought to determine whether reboxetine's weight-attenuating effect was accompanied by a beneficial effect on metabolic and endocrine parameters relevant to antipsychotic-induced weight gain and obesity. Method: Blood samples at baseline and at the end of the 6-week trial were available for 54 participants who participated in previous double-blind, placebo-controlled studies of reboxetine (4 mg BID) addition to olanzapine-treated schizophrenia patients. Fasting glucose, lipid profile, insulin, leptin, cortisol, dehydroepiandrosterone (DHEA), prolactin, and thyroid-stimulating hormone (TSH) were analyzed. Results: In contrast to the olanzapine/placebo group, the olanzapine/reboxetine group exhibited a reduction in blood triglyceride (p < 0.05) and leptin (p < 0.05) levels, and elevation in cortisol (p < 0.05) and DHEA (p < 0.008) levels. No significant between-group differences were detected in the changes in cholesterol, glucose, insulin, TSH, and prolactin. Conclusions: Reboxetine addition resulted in meaningful improvement of some metabolic and endocrine measures associated with olanzapine-induced weight gain. The potential role of reboxetine in the prevention of olanzapine-induced weight gain and cardio-metabolic morbidity merits further large-scale, long-term investigation.