DRD2 and Lesch-Nyhan syndrome: However, metoclopramide (a D2 dopamine receptor antagonist) can worsen extrapyramidal symptoms and dystonia in LNS patients because they also have dopaminergic dysfunction.[11] Before administering general anesthesia, the airway anatomy should also be carefully assessed because repeated destruction and scarification of the oral mucosa, tongue and lips by persistent self-biting increase the likelihood of difficulties in securing the airway such as limitations in mouth opening, airway bleeding, or lack of teeth.