A gag reflex is a condition in which the gag reflex is significantly enhanced because of anatomical abnormalities of the oral and nasal cavity or unpleasant memories of past dental treatment. The patient in the present case was a 31-year-old male who had been referred to our clinic because of difficulty undergoing normal dental treatment as a result of a severe gag reflex, the onset of which had occurred at around the age of 20 years. Based on the results of an oral examination, a long-term treatment plan to be performed under intravenous sedation was developed. We first attempted to manage him with deep sedation using propofol and midazolam, but he had difficulty controlling his reflexes and also vomited during the dental treatment. In this case, we considered that peripheral input from stimulation of the oral mucosa and input from the cerebral cortex, such as past discomfort and fear, had been responsible for inducing vomiting, and we tried a new approach to suppress the gag reflex. We decided to use the histamine H1 receptor-antagonist hydroxyzine hydrochloride for direct inhibition of the vomiting center, pentazocine for analgesia against nociception, and famotidine, which antagonizes histamine H2 receptors and inhibits gastric acid. As a result, the patient’s gag reflex was sufficiently suppressed, and the dental treatments were performed without difficulty. Although various reports of patients with severe gag reflexes have been made, various management methods that are appropriate to the patient’s background, treatment, and the facility environment in which the anesthesia management is being performed should be considered, so that the best method can be selected for each patient.
