RESUMEN
Phentermine is a sympathomimetic amine, like amphetamine, which is one of the most often prescribed drugs for weight loss. Although exact mechanism of phentermine causing psychosis is still not clear, numerous reports already showed that phentermine can induce psychosis. Psychotic symptoms are generally resolved once the medications are stopped. In contrast, we present a case of a 25-years-old Asian female patient who developed psychotic symptoms repeatedly after phentermine administrations. This case suggests that phentermine can cause psychotic episodes repeatedly, resulting in chronic occupational and social impairment. Therefore, a precautious measure such as government regulations for physicians prescribing and an education for patients taking phentermine are urgently needed.