Additional treatment with clarithromycin reduces fever duration in patients with influenza

Influenza virus infection-induced inflammatory responses are associated with fever and other symptoms. Although macrolide antibiotics (macrolides) provide anti-inflammatory effects, these effects have not been well studied in influenza patients.

We examined the effects of clarithromycin on influenza symptoms. A randomized, prospective, and open-label study was performed between December 2010 and March 2011 and between December 2012 and March 2013 in patients with pandemic A/H1 2009 influenza or seasonal influenza virus infections. Patients aged >15 years received either neuraminidase inhibitors (control group) or clarithromycin plus neuraminidase inhibitors (clarithromycin group). Body temperature and other symptoms were recorded for 5 days after initiating treatment. Serum interleukin (IL)-6 and IL-8 levels were also measured.

Herein, 79 patients were enrolled over the two influenza seasons, and data from 63 patients were analyzed. All patients showed fever and other symptoms, including rhinorrhea (n=38), cough (n=50), sore throat (n=39), arthralgia or myalgia (n=46), and general malaise (n=50). Fever duration was approximately 42% shorter in patients with temperatures ≥38.5°C (p=0.02), decreasing from 42 h to 24 h. Among patients with pandemic influenza infections (n=20), the rhinorrhea improvement rate was higher in the clarithromycin group (p=0.03; 88% vs. 20%). Serum IL-6 levels decreased 5 days after treatment, but no differences between the two groups were detected.

Clarithromycin may have the additional clinical benefit of improving fever, the main symptom of influenza, in patients treated with neuraminidase inhibitors.