Aminobutyric acid
In 2005–06, Neomycin was the fifth-most-prevalent allergen in patch test results (10.0%). It is also a known GABA "gamma"-Aminobutyric acid antagonist and can be responsible for seizures and psychosis. Like other aminoglycosides, neomycin has been shown to be ototoxic, causing tinnitus, hearing loss, and vestibular problems in a small number of patients. Patients with existing tinnitus or sensorineural hearing loss are advised to speak with a healthcare practitioner about the risks and side effects prior to taking this medication.