People with symptoms of a respiratory tract infection, including a cold and sore throat, may not always benefit from taking ibuprofen, according to a study carried out by the University of Southampton.

Researchers said that, compared with paracetamol (also known as acetaminophen, the active ingredient in Tylenol), ibuprofen does not live up to expectations.

According to the researchers, "compared with paracetamol, ibuprofen or a combination of both ibuprofen and paracetamol provide no advantage for patients overall with respiratory tract infections," a surprising find considering the frequency with which the anti-inflammatory drug ibuprofen is used in treating colds and sore throats.

The researchers also said there is no clear benefit to inhaling steam, another common treatment.

"Paracetamol, ibuprofen or a combination of both are the most common courses of treatment for respiratory tract infections," said research leader Paul Little. "Clinicians should probably not advise patients to use steam inhalation in daily practice as it does not provide symptomatic benefit for acute respiratory infections and a few individuals are likely to experience mild thermal injury. Similarly, routinely advising ibuprofen or ibuprofen and paracetamol together than just paracetamol is also not likely to be effective"

Little did add, however, that the research suggests "ibuprofen is likely to help children, and those with chest infections."

In a randomized study of 899 patients seeking treatment for a respiratory tract infection, 50 percent to 70 percent those who were prescribed ibuprofen or a combination of ibuprofen and paracetamol came back to the doctor within a month with worsening symptoms or new symptoms.

Little said he was surprised at the results and suggested that such treatment may contribute the the progress of an illness.

"This may have something to do with the fact the ibuprofen is an anti-inflammatory," he said. "It is possible that the drug is interfering with an important part of the immune response and leads to prolonged symptoms or the progression of symptoms in some individuals. Although we have to be a bit cautious since these were surprise findings, for the moment I would personally not advise most patients to use ibuprofen for symptom control for coughs colds and sore throat."

The National Institute for Health Research-funded study is published in the British Medical Journal.