Allergy Medicine Fails to Reduce Flu-Like Syndrome in Relapsing-remitting MS Patients, Study Shows

The allergy treatment cetirizine fails to alleviate a flu-like condition that interferon-beta treatment generates in people with relapsing-remitting multiple sclerosis (RRMS), a clinical trial indicates.

The results, which surprised researchers, apply to flu-like syndrome, or FLS. Cetirizine is an over-the-counter medicine sold under the brand names Zirtec, Zyrtec, Reactine, and Triz.

The pilot clinical trial (2013-001055-12) is known as Flu-LIGHT, for Flu Like Inhibition Giving anti-Histamine Therapy.

The study was published in the journal PLOS|One. Its title is “Management of flu-like syndrome with cetirizine in patients with relapsing-remitting multiple sclerosis during therapy with interferon beta: Results of a randomized, cross-over, placebo-controlled pilot study.”

FLS affects roughly 75 percent of patients who take interferon-beta, also known as IFN-beta. It can cause fever, chills, muscle pain, weakness, and headache.

The symptoms commonly occur three to six hours after an IFN-beta injection and last up to 24 hours. Although FLS usually subsides in the first three months of IFN-beta therapy, it persists in some patients, causing them to miss doses or even discontinue the treatment.

Cetirizine is an antihistamine for hay fever and allergies.

The purpose of the pilot, randomized, placebo-controlled trial was to determine whether cetirizine could alleviate RRMS patients’ FLS. Researchers had thought it might because Cetirizine reduces levels of IL-6, an inflammation-related protein associated with the development of FLS.

Thirty-nine RRMS patients took part in the study. They had received IFN-beta for at least three months, and a standard therapy for FLS that had failed to stop the condition. That therapy was either acetaminophen, a pain reliever and fever reducer, or a non-steroid anti-inflammatory drug.

All patients continued their IFN-beta treatment as they took cetirizine. They were divided into two groups. Group 1 received four weeks of standard therapy for FLS plus a placebo, followed by four weeks of standard therapy plus cetirizine. The sequence was reversed in Group 2: Patients received cetirizine plus standard therapy for four weeks, and then a placebo.

Patients did self-assessments of how much discomfort their FLS caused them.

There were no significant changes in the two groups’ average self-assessment scores at four and eights weeks of treatment, suggesting that cetirizine does not offer significant benefits to RRMS patients with FLS.

“The addition of a [cetirizine] to the standard of care for IFNβ-induced FLS in patients with RRMS does not seem to improve symptoms significantly compared with placebo,” the team wrote. “FLS continues to be inadequately treated in many RRMS patients. Further investigations are needed to elucidate the underlying mechanisms of IFNβ-induced FLS and develop adequate strategies for prevention and treatment.”