The World Health Organization (WHO) on Tuesday recommended that people experiencing COVID-19 symptoms avoid taking ibuprofen and other anti-inflammatory drugs, which are commonly used to treat fever and mild to severe pain.

The WHO’s recommendation comes after a study published on March 11 in The Lancet medical journal speculated that an enzyme stimulated by anti-inflammatory drugs like ibuprofen could potentially worsen coronavirus symptoms.

According to the study, drugs like ibuprofen increase the number of ACE-2 receptors on cell surfaces, which COVID-19 uses to infect cells. 

In a tweet Saturday, French Health Minister Olivier Véran noted that drugs like ibuprofen and aspirin can worsen coronavirus symptoms.

When asked about the study, WHO spokesperson Christian Lindmeier told reporters in Geneva that the agency’s experts were looking into the study.

"In the meantime, we recommend using … paracetamol, and do not use ibuprofen as a self-medication. That's important," he said. However, he also noted patients who have been prescribed ibuprofen by a health care professional should use their own discretion regarding whether to continue using it.

However, some experts say that there is no evidence to substantiate the claims that anti-inflammatory drugs could exacerbate coronavirus symptoms.

“It’s all anecdote, and fake news off the anecdotes,” Dr. Garret FitzGerald, chair of the Department of Pharmacology at the Perelman School of Medicine at the University of Pennsylvania, is quoted as saying by the New York Times. “That’s the world we are living in.”

“Until there is evidence, there is no reason at all to be issuing public health guidance,”  he added.

In general, the human body is able to fight infections better when its temperature is higher, which is the purpose of a fever. However, for every 1 degree Celsius that body temperature increases, the metabolic rate - the amount of energy the body uses at rest in a given time frame - also rises by 12%.

“We don’t want to pay that metabolic price when we don’t have to, so we only make a higher temperature when we need it,” Paul Offit, an infectious disease expert at the University of Pennsylvania and Children’s Hospital of Philadelphia, is quoted as telling the New York Times.

Thus, while taking drugs such as aspirin, paracetamol or ibuprofen can alleviate a fever, doing so may mean the body will need more time to fight an infection.