Oseltamivir use should follow label for most hospitalized patients

Oseltamivir, an antiviral agent for the treatment of influenza, should be started within 48 hours of symptom onset for most hospitalized patients and outpatients who are suspected of H1N1 or other strains of the flu, according to a recent report in the American Journal of Health-System Pharmacy.

FDA grants waiver for influenza test

According to the prescribing label, oseltamivir is indicated for the treatment of uncomplicated influenza in individuals who are two weeks of age or older and who have had symptoms for no longer than two days. The recommended oral dose for those 13 years and older is 75 mg twice daily for up to five days. For individuals with renal insufficiency, the recommended oral dose is 30 mg twice daily or once daily for five days, depending on the degree of renal insufficiency.

In this recent report by Brianna McQuade, PharmD and Melissa Blair, PharmD, they reviewed the literature regarding the off-label use of oseltamivir. They found six reports in which oseltamivir was administered more than 48 hours after symptom onset, use of double the standard dose, or use beyond five days.

They concluded that following label guidelines of oseltamivir may increase survival of patients who are infected with H1N1 and require ICU admission. For those individuals who are hospitalized as general medicine patients or outpatients infected with H1N1 or other influenza strains, oseltamivir does not provide any benefits if given 48 hours after symptom onset.

“There are scant data supporting the use of oseltamivir for longer than five days in any patient population, with the possible exception of critically ill H1N1-infected ICU patients, who may benefit from high-dose treatment in some cases,” the authors reported.

The article was updated on Jan. 22, 2015 with the correct dosing for oseltamivir in adults with various degrees of renal insufficiency.