Tamiflu Efficacy May Differ With Flu Type

Oseltamivir (Tamiflu) treatment initiated within 48 hours of influenza symptom onset was associated with significantly lower mortality in critically ill patients with influenza A/H3N2, according to a study published online in Clinical Infectious Diseases. However, early treatment with oseltamivir showed no effect on mortality among patients with influenza A/H1N1 or influenza B.

“Severely ill patients with suspected influenza should be promptly treated with oseltamivir, particularly when A/H3N2 is circulating,” researchers wrote. “The efficacy of oseltamivir should not be assumed to be equal against all types of influenza.”

The study included all adults in intensive care units (ICUs) in Greece with lab-confirmed influenza during the seasons 2010-2011 through 2017-2018 who received oseltamivir. Researchers assessed whether earlier treatment (within 48 of symptom onset) with oseltamivir reduced mortality compared with later treatment among the 1330 patients in the study, 46.8% of whom died in the ICU.

Earlier treatment with oseltamivir had no affect on overall mortality compared with later treatment after adjustment, the study found. Although for ICU patients with influenza A/H3N2, early oseltamivir treatment was linked with a 30% decrease in mortality, a drop researchers characterized as “especially significant.”

Among influenza survivors, the median length of stay in the ICU was 1.8 days shorter when oseltamivir treatment was initiated earlier, researchers reported.

—Jolynn Tumolo

References

Lytras T, Mouratidou E, Andreopoulou A, Bonovas S, Tsiodras S. Effect of early oseltamivir treatment on mortality in critically ill patients with different types of influenza: a multi-season cohort study. Clinical Infectious Diseases. 2019 February 7;[Epub ahead of print].