Study shows that monotheraphy more effective in fighting flu

A randomized, placebo-controlled trial has shown that a combination of the drugs oseltamivir - tamiflu - and zanamivir - relenza - is less effective than oseltamivir monotherapy and it is not significantly more effective than a zanamivir monotherapy.

The trial was conducted with adults that presented influenza symptoms in France during a seasonal influenza epidemic in 2008 and 2009. Catherine Leport, from the University of Paris, France, and her colleagues conducted the study at general practices throughout France as reported in the recent issue of the journal PLoS Medicine.

Zanamivir and oseltamivir have been important drugs in the last few years to limit the impact of seasonal influenza collectively by slowing the virus’ spread to create time for vaccine production and in individuals by reducing mortality and morbidity.

The authors compared the effectiveness of the monotherapy of either drug with the combination to inform future influenza pandemic planning.

Adults who visited the general practices either received 75 milligrams of oral oseltamivir twice a day with 10 milligrams of zanamivir inhaled twice a day or one of the drugs plus a placebo.

The combination of oseltamivir and zanamivir was clinically and virologically less effective than oseltamivir alone. The combination was found to not be significantly different on time to resolution of symptoms than the zanamivir alone.

The study was conducted in three groups, with 192 people in group one, 176 in group two and 173 in group three. In total, 447 people were infected with influenza A in the study.

The authors concluded that their findings should caution the use of oseltamivir and zanamivir in combination of adult outpatients with influenza and that oseltamivir alone should be used for treatment.