Selective serotonin reuptake inhibitor (SSRI) antidepressants are some of the most widely prescribed drugs in the world, and new research suggests they could also protect against serious infections and life-threatening sepsis. Scientists at the Salk Institute studying a mouse model of sepsis uncovered how the SSRI fluoxetine can regulate the immune system and defend against infectious disease, and found that this protection is independent to peripheral serotonin. The findings could encourage additional research into the potential therapeutic uses of SSRIs during infection.

“When treating an infection, the optimal treatment strategy would be one that kills the bacteria or virus while also protecting our tissues and organs,” commented professor Janelle Ayres, PhD, holder of the Salk Institute Legacy Chair and Howard Hughes Medical Institute Investigator. “Most medications we have in our toolbox kill pathogens, but we were thrilled to find that fluoxetine can protect tissues and organs, too. It’s essentially playing offense and defense, which is ideal, and especially exciting to see in a drug that we already know is safe to use in humans.”

Ayres is senior author of the team’s report in Science Advances. In their paper, titled “Fluoxetine promotes IL-10–dependent metabolic defenses to protect from sepsis-induced lethality,” the investigators stated, “Our work reveals a beneficial ‘off-target’ effect of fluoxetine, and reveals a protective immunometabolic defense mechanism with therapeutic potential.”