The use of benzodiazepines for sedation undoubtedly enhances the perception and tolerance during FB and they are by far the most widely used drugs because of their ease of administration, their speed of action and the possibility to administer an antidote. The drawback of these sedative agents is related to a high variable individual sensitivity, which can lead to drug overdose and to severe respiratory depression requiring ventilatory assistance. In addition, their sedative and amnesic effects might persist several hours after the procedure.