What are antiviral medicines for the flu?
Antivirals are medicines that make it harder for
viruses to grow in your body. You can take an
influenza (flu) antiviral either to prevent the flu or
to treat the flu after you have it. Their main use is to help protect people
who are at high risk for serious complications from the flu, such as
There are two types of
antiviral medicines for the flu:
There are two main types of influenza virus-A and B. Type
A causes most flu outbreaks. The M2 inhibitors help fight influenza A viruses.
The neuraminidase inhibitors help fight both A and B viruses.
These antiviral medicines will not help fight other types of viral
infections, such as colds.
Note: How well
antiviral medicines work can vary from year to year as flu viruses change. For
the past few years, the U.S. Centers for Disease Control and Prevention (CDC)
has advised doctors not to use the M2 inhibitors (amantadine or rimantadine) to
treat or prevent the flu.1 These medicines have not
worked against most types of the flu virus. If you decide to take an antiviral,
your doctor can prescribe the best one for you. For the most recent information
on antiviral drugs, see the Centers for Disease Control and Prevention’s
influenza information at www.cdc.gov/flu.
Who can take antivirals?
Antivirals are most often
used to help control flu outbreaks in settings such as nursing homes and
hospitals, where people who are at high risk for serious problems live close
Antivirals may be given to:
- People who are at high risk for serious
complications from the flu. This includes children, people 65 and older, and
those with long-term (chronic) diseases or a
weak immune system.
- People who did not
have a flu shot and are in close contact with anyone at high risk for
- People at high risk for complications who are not
able to get a flu shot.
Doctors may also prescribe antivirals for anyone who has
been diagnosed with the flu within the first 2 days of illness. This may help
shorten the course of the flu and help prevent its spread.
Who should not take antiviral medicine?
who have serious breathing problems, such as
COPD, should not use Relenza.
antivirals are not prescribed for children. If your child needs an antiviral,
your doctor can prescribe the correct type.
Experts don't know if
antivirals are safe during pregnancy or for babies. Ask your doctor to help you
weigh the benefits and risks of taking an antiviral medicine if you are at risk
for the flu and you are pregnant or breast-feeding (which could pass the drug
to your baby through the milk). Also ask your doctor if you should get a flu
Antivirals can cost a lot-from about $70 to $100. They may
not be worth the cost for people who are not at high risk from the flu.
What are the benefits of taking antiviral medicine?
- Antiviral medicines can shorten the course
of flu by about 1 day if you take them within 2 days of getting sick.
- They make you less likely to spread the flu.
- They can
help control flu outbreaks in settings such as nursing homes, where people are
at high risk for complications.
- They may help prevent flu in
people who did not get a flu shot.
What are the risks of taking antiviral medicine?
- Antiviral medicines for the flu may cause
minor problems, such as diarrhea, sinus infection (sinusitis), or nausea and vomiting (more common with
- Relenza may cause breathing problems in people who have
serious lung problems.
- Tamiflu and Relenza may increase the risk for self-injury and
confusion in people who have the flu, especially children. People who use
Tamiflu or Relenza should be watched closely, and any odd behavior should be
reported to a doctor.
- Taking antivirals when you don't really need them may lead to
drug-resistant viruses that are harder to
If you need more information about the flu, see the