The Centers for Disease Control (CDC) now recommends against the use of two well-known anti-viral agents for treatment or prevention of the flu this year. Doctors report widespread viral resistance to amantadine and rimantadine. The two newer antivirals, oseltamivir (Tamiflu) and zanamivir (Relenza) are still effective and recommended to prevent complications in high-risk patients. This would include seniors, asthmatics, and diabetics.
While it is disturbing to discover that viral shifts have been made a standard medication ineffective, this development will not have much of an impact on the spread and care of influenza both in the US and Europe. Both agents were older therapies that were only effective against influenza A. In addition, they caused enough side effects (insomnia, anxiety, and jitteriness) to limit their acceptance with patients.
The newer anti-viral agents Tamiflu and Relenza still can be used for both prevention and treatment of both influenza A and B. These drugs are neuraminidase inhibitors that act blocking the receptor sites on the cell and prevent the virus from replicating. However, to avoid the development of resistance to these agents, public health officials urge physicians to limit their use in the current flu season. They feel it is important to preserve these anti-virals for an outbreak of severe flu for which there is little or no vaccine.
