Researchers at Beaumont Hospital in Royal Oak, Mich., are enrolling patients in a phase 2 trial to evaluate a combination of naltrexone and ketamine as a treatment for COVID-19.

Low-dose naltrexone is used to treat pain and inflammation in multiple sclerosis, Crohn’s disease, fibromyalgia and other pain conditions. Ketamine, an anesthetic, shows anti-inflammatory effects when taken early in the inflammatory process.

The study aims to see if the combination can lessen the severity of COVID-19 symptoms by reducing inflammation.