Pharmacodynamics of drug-induced weight gain.

Body weight gain during treatment with drugs for any kind of disease may represent improvement of the disease itself. However, sometimes these drug-induced alterations of the body's appetite-regulating mechanisms result in excessive weight gain, thus jeopardizing compliance with prescribed medication. A number of drugs are capable of changing body weight as an adverse consequence of their therapeutic effect. Included in this category are the psychotropic drugs such as antipsychotics, antidepressants and mood stabilizers. Antipsychotics are well-known culprits of weight gain. The low-potency (e.g., chlorpromazine and thioridazine) and atypical agents (e.g., clozapine, olanzapine, quetiapine and risperidone) are most often associated with weight gain. Antidepressants such as tricyclic antidepressants and monoamine oxidase (MAO) inhibitors are most often associated with significant weight gain. The tertiary tricyclic antidepressant amitriptyline is thought to induce the most weight gain. Mood stabilizers such as lithium carbonate, valproic acid and carbamazepine also induce weight gain in a considerable number of patients. Treatment with corticosteroids is associated with dose-dependent body weight gain in many patients and corticosteroid-induced obesity aggravates other corticosteroid-associated health risks. Insulin therapy in diabetic patients usually increases body weight. Finally, sulfonylurea derivatives, antineoplastic agents used for the treatment of breast cancer and several drugs used in migraine prophylaxis may cause body weight gain as well. (c) 2001 Prous Science. All rights reserved.