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Updated: Sep 21, 2026

Self-Administration of Drugs in Mouse Models of Feeding and Obesity
Published on: June 8, 2021
[Randomized, open label study on the use of ranitidine at different doses for the management of weight gain
Andrea López-Mato1, Javier Rovner, Gonzalo Illa
1Instituto de Psiquiatría Biológica Integral, Buenos Aires, Argentina. ipbi@arnet.com.ar
Abstract:
Potential weight gain must be taken into account in the patient's comprehensive treatment approach when initiating antipsychotic treatment with Olanzapine. There are effective preventive and therapeutic pharmacological interventions to control this adverse effect. Not addressing this eventual treatment aspect of Olanzapine treatment may compromise the patient's health and his/her compliance with the pharmacological treatment indicated in serious psychiatric conditions. The decision to use a molecule must be made taking into account its efficacy, efficiency and adverse effect profile. In this study, concomitant administration of Ranitidine prevented or corrected weight gain in 59.6% of cases. Patients followed by 16 weeks had shown the following results: Olanzapine without Ranitidine, exhibited an average weight gain of 3.4 kilograms, ranging between -2.5 and +16 kg. This implies an average increase of 1.19 in BMI for this group. Patients treated additionally with Ranitidine at doses of 300 mg, a 0.9 kilogram weight gain ranging between -4 and +10.6 kg was observed, implying an average BMI change of 0.34. In patients treated with Ranitidine at doses of 600 mg, the weight gain curve trended toward normalization with a 1.6 kilogram decrease, ranging between -15 and +7 kilograms, accounting for a decrease of 0.6 points in BMI. While more extensive studies are required, our interest with this study is to demonstrate that we can count on a potentially simple and useful response for the treatment of weight gain associated with Olanzapine use. The risk/benefit ratio is a paradigm in the practice of medicine. In the case of Olanzapine, the scale clearly tips in favor of the latter, making it the drug of choice in the treatment of schizophrenia and other psychotic disorders.
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