Tamiflu (Oseltamavir) and Relenza (Zanamavir) for Treatment of Influenza
These newer anti-viral medications are effective for the treatment and prevention of infection from influenza A and B. Zanamavir is an inhaled medication, while oseltamivir is an oral medication; both work by preventing the influenza virus from replicating inside the cells of a person’s respiratory tract. Either medication is effective at reducing the severity and duration of influenza symptoms, however, they need to be taken within 48 hours of the start of influenza symptoms to be effective. Either medication is taken for 5 days, and can be used in children.
Oseltamavir is known to cause side effects of nausea and vomiting, but if taken with food these side effects are decreased. Most people don’t have to stop oseltamavir as a result of these side effects. Because zanamavir is an inhaled medication, it doesn’t cause any more nausea or vomiting than placebo.
There have been reports of people with asthma or COPD experiencing worsening breathing symptoms after inhaling zanamavir. Many studies show that zanamavir appears to be safe for people with asthma, showing no difference when compared to placebo, and no change in methacholine challenge testing (meaning the lungs were no more sensitive after taking zanamavir). Despite this, the Food and Drug Administration has urged caution for people with asthma or COPD to use caution with zanamavir, and to consider using albuterol a few minutes prior to using zanamvir to prevent any worsening asthma symptoms.
Learn more about the treatment of influenza in asthmatics.
Sources:
Nathan RA et al. Management of Influenza in Patients With Asthma or Chronic Obstructive Pulmonary Disease. Ann Allergy Asthma Immunol. 2001;87:447-54.
Patient Information Sheet for Zanamavir. CDC Website. Accessed April 29, 2009.
DISCLAIMER: The information contained in this site is for educational purposes only, and should not be used as a substitute for personal care by a licensed physician. Please see your physician for diagnosis and treatment of any concerning symptoms or medical condition.
