Acute Sensorineural Hearing Loss After Abuse of an Inhaled, Crushed Oxymorphone Extended-Release Tablet

Oxymorphone, a semisynthetic μ-opioid receptor agonist, is the major active metabolite of oxycodone. It is a highly potent narcotic analgesic due to its high lipid solubility, which allows it to readily cross the blood-brain barrier and enter the central nervous system. It is available as both an immediate-release and extended-release (ER) formulation. Oxymorphone can be abused by injection or inhalation of crushed tablets; thus, in 2011, the manufacturer of ER oxymorphone reformulated the drug with crush-resistant technology to deter its misuse and abuse. We describe the case of a previously healthy, 24-year-old male who experienced reproducible acute subjective bilateral temporary hearing loss that occurred after inhalation of oxymorphone. He presented to the emergency department complaining of acute bilateral hearing loss after he reported snorting a crushed oxymorphone ER 30-mg tablet. Emergency department evaluation revealed obvious bilateral hearing loss as well as coincidental aspiration pneumonia. The patient's medical history revealed that he had experienced a similar episode of hearing loss after a previous episode of oxymorphone inhalation. His hearing loss began to improve 3 hours after presentation to the emergency department and was completely resolved by the following day. Use of the Naranjo adverse drug reaction probability scale revealed oxymorphone to be a probable cause of this patient's acute hearing loss (score of 6). The mechanism of action of opioid-associated hearing loss (OAHL) is not completely understood, but it is thought to be due to disturbances within the cochlea, such as cochlear ischemia. To our knowledge, this is only the second published case report of acute reversible hearing loss following oxymorphone inhalation and the first published case report of reproducible OAHL. Since opioid misuse continues to be prevalent despite attempts at reformulations to make the drugs crush resistant, a high degree of clinical suspicion is needed to evaluate and treat patients who present with unique findings after episodes of substance abuse, especially those related to tamper-resistant formulations.