Colds and the Flu - Medications

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Highlights	Risk Factors	Resources
Introduction	Prevention	References
Diagnosis	Treatment
Complications	Medications

Candidates. Their current use in different age and patient groups are as follows:

Adults. Both are approved for treatment in adult patients.
Children. Oseltamivir is approved for use in children age one and older. Studies report significant reduction in symptoms and in the incidence of ear infections. Zanamivir is approved for children over age 7, and studies are currently underway to determine its safety in younger children.
High-Risk Patients. Recent studies indicate they are safe and effective in patients with serious medical problems or other conditions that put them at risk for complications of flu.

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Comparing Anti-Viral Medications for the Flu

	Amantadine (Symmetrel) and rimantadine (Flumadine)	Oseltamivir (Tamiflu) and Zanamivir (Relenza)
Type of Drug	M2 inhibitor	Neuraminidase inhibitor
Treats infection with Influenza type A?	Yes	Yes
Treats infection with Influenza type B?	No	Yes
Useful for 2006 - 2007 flu season?	No -- many strains of influenza A have become resistant to these drugs.	Yes
Shortens duration of flu symptoms?	Yes	Yes
Reduces transmission of the virus (nasal shedding)?	No	Yes
Prevents respiratory complications of the flu such as pneumonia and bronchitis?	No	Maybe
Sources: CDC, The Lancet

Antiviral drugs are not a substitute for vaccines. Oseltamivir and Relenza may be important as add-on protection agents during a serious epidemic or pandemic, when used in conjunction with public health measures such as quarantine and rigorous hygiene practices.

Oseltamivir is the only drug studied for protection against avian flu. Although it is active in lab experiments, it has not been successful clinically. Experience is very limited, however, and it is not clear whether people infected with avian flu received the drug in time for it to be useful. Further study is necessary.

Viral Influenza Vaccines

Description of Vaccines. Vaccines against influenza employ inactivated (not live) viruses. They are designed to provoke the immune system to attack antigens contained on the surface of the virus. (Antigens are foreign molecules that the immune system specifically recognizes as alien and so targets for attack.)

Unfortunately, the antigens in these influenza viruses undergo genetic alterations (called antigenic drift) over time, so they are likely to become resistant to a vaccine that worked in the previous year. Vaccines are then redesigned annually to match the current strain.