Severe weight gain as an adverse drug reaction of psychotropics: Data from the AMSP project between 2001 and 2016.

Severe weight gain induced by psychotropics is a known problem in psychiatry. Various drugs from different classes may lead to weight gain that may further lead to potentially life-shortening diseases, such as diabetes or cardiovascular disease. A total of 344 cases of severe weight gain (>10% of body weight) have been documented by the drug safety in psychiatry program AMSP between 2001 and 2016. Patients gained 12.7 ± 5.5 kg weight within 12±15 weeks. This equals a Body Mass Index (BMI) gain of 4.4 ± 1.9 kg/m² to a final BMI of 28.8 ± 5.5 kg/m². In addition, 142 retrospective reports documented at admission have been analyzed. Within one year these patients gained 6.4 ± 4.0 kg/m² to a final BMI of 31.9 kg/m². The weight gain was extreme in some cases. For example, 35% of the patients gained more than 20 kg. On average the patients reached overweight or even adiposity. Only 27% of the patients could loose some weight at the end of their stay. This emphasizes the relevance of this long-term problem for the patients' health. Mostly second generation antipsychotics, and therein olanzapine, as well as antidepressants and anticonvulsants have been imputed. Severe weight gain is a slow process and it is rarely documented as adverse drug reaction under real-life conditions compared to the high percentage of patients with weight gain in clinical studies. It might often remain unnoticed due to shorter stationary treatment and changing treatment settings.