Tamiflu may work best alone

PARIS, Nov. 3 (UPI) -- A randomized, placebo-controlled trial finds using influenza drugs tamiflu and relenza together is less effective than tamiflu alone, French researchers say.

Catherine Leport of the University of Paris and colleagues says the trial involved 541 adults presenting with influenza symptoms at general practices throughout France during the seasonal influenza epidemic in 2008-2009.

Adults who visited their doctor with symptoms of an influenza-like illness within 36 hours and who had a positive influenza A rapid test were randomized to oral tamiflu, or oseltamivir, 75 mg twice daily plus relenza, or zanamivir 10 mg by inhalation twice daily; oral oseltamivir 75 mg twice daily plus inhaled placebo or zanamivir 10 mg by inhalation twice daily plus oral placebo.

The study, published in the journal PLoS Medicine, finds overall the tamiflu-relenza combination was both virologically and clinically less effective than tamiflu alone.

The findings call for caution in the use of the oseltamivir-zanamivir combination in treatment of adult outpatients with influenza, the study authors say.