Olanzapine is an effective antipsychotic drug and the only one, so far, to be demonstrated to minimize grey matter loss. However, it can lead to significant weight gain which can put people at risk of cardiovascular problems and diabetes. Previous trials have shown that switching from standard oral tablets to orally-disintegrating tablets can lead to weight loss but these have only been short-term studies. A study of 26 patients in Canada who switched tablets found that, on average, they had lost 2.7kg after a year. The peak weight loss was observed at 6 months although significant weight loss was achieved after only three. The majority of patients (81.9%) had lost weight after a year while 18.1% showed no change or a weight gain.
Bharat, Chawla and Luxton-Andrew, Heather - Long-term weight loss observed with olanzapine orally disintegrating tablets in overweight patients with chronic schizophrenia. A 1-year, open-label prospective trial Human Psychopharmacology March 2008, 23(3), 211-216