Common drugs may help dangerous viruses spread through the body

Medications are designed to treat diseases and relieve symptoms, but some can also produce unintended effects that put patients at risk. While side effects are common with many treatments, researchers have identified a particularly concerning possibility involving drugs used to control inflammation.

Scientists at the Norwegian University of Science and Technology (NTNU) have discovered that a widely used class of anti-inflammatory medications may make it easier for certain viruses to infect cells and spread throughout the body.

"We have found a surprising and potentially serious side effect of a class of anti-inflammatory drugs. They can help viruses spread more easily in the body," says Denis Kainov, a professor at the Department of Clinical and Molecular Medicine at the Norwegian University of Science and Technology (NTNU).

The medications at the center of the findings belong to a class called Janus kinase inhibitors, or JAKs. These drugs are widely prescribed to control inflammation, but their effects on the immune system may also leave the body more vulnerable to viral infections.

"Among the viruses that more easily affect the body with the help of these drugs are Rift Valley fever virus, influenza A, adenovirus and SARS-CoV-2, the virus that causes COVID-19," Kainov says.

These viruses can cause significant illness, making any treatment that potentially increases their ability to spread a serious concern.

In a new study published in NAR Molecular Medicine, Kainov and his colleagues investigated how JAK inhibitors influence the body's ability to defend itself against viruses.

"JAK inhibitors are often prescribed for autoimmune diseases and inflammatory conditions such as rheumatoid arthritis," says Erlend Ravlo, a PhD research fellow at NTNU and first author of the article.