Taking anti-inflammatory drugs? Here is what to know about viral infections

If you take daily medication for joint pain or inflammation, you might not think much about how it affects your immune system. But scientists at the Norwegian University of Science and Technology (NTNU) have found that a widely used group of anti-inflammatory drugs may unintentionally make it easier for certain viruses to spread in the body.

The researchers studied JAK inhibitors, a class of medicines often prescribed for rheumatoid arthritis and other inflammatory conditions. Their laboratory findings, published in the journal NAR Molecular Medicine, suggest these drugs can weaken a key part of the immune system that normally fights off viral infections.

Because this was laboratory research using human cells and miniature organ models rather than a study of patients in clinics, it shows a possible biological mechanism rather than proving exactly what happens in every person taking these medicines.

Which viruses are affected?

According to the NTNU team, the viruses that may spread more easily when these drugs are used include:

• Influenza A, which causes seasonal flu
• SARS-CoV-2, the virus that causes COVID-19
• Adenovirus, a common cause of colds and eye infections
• Rift Valley fever virus

"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," said Denis Kainov, a professor at NTNU's Department of Clinical and Molecular Medicine.

How do these drugs change your defenses?

Your body uses specific genes to signal healthy cells to defend themselves against viruses. The study found that JAK inhibitors suppress this important signaling pathway.

Erlend Ravlo, a PhD research fellow at NTNU and the study's first author, explained that while these medications effectively reduce inflammation, they also interfere with the mechanisms that protect the body from viral attacks. The scientists tested this using human cells from the lungs, eyes, and brain, as well as miniature organ models grown in the laboratory.

What should you do if you take JAK inhibitors?

The researchers suggest doctors should be cautious when prescribing these medications during periods of high viral transmission or outbreaks. However, do not stop taking your medicine or change your dose on your own. Stopping suddenly could cause your inflammatory condition to flare up.

Talk to your doctor or pharmacist if you have questions about your treatment, especially during flu season or if you feel unwell. They can weigh the benefits of controlling your inflammation against the potential risks.

The bottom line is that managing inflammation and protecting yourself from viruses both matter, so work with your healthcare provider to find the safest balance for you.