 As part of the REMS requirements, prescribers and patients must adhere to the required cardiac monitoring with echocardiograms to receive fenfluramine.At higher therapeutic doses, headache, diarrhea, dizziness, dry mouth, erectile dysfunction, anxiety, insomnia, irritability, lethargy, and stimulation have been reported with fenfluramine.There have been reports associating chronic fenfluramine treatment with emotional instability, cognitive deficits, depression, psychosis, exacerbation of pre-existing psychosis (schizophrenia), and sleep disturbances.