Penthrox, also known as methoxyflurane, is a handheld inhaler used for the emergency relief of moderate to severe pain in conscious adult patients with trauma, self-administered under supervision of a trained person. It was banned in the United States by the FDA in 2005 due to safety concerns, specifically the risk of severe and irreversible nephrotoxicity and hepatotoxicity. | Mahyar "Max" Maddahali, MD