Health Library Should I Take Antiviral Medicine for the Flu?From Healthwise

This information will help you understand your choices, whether you share in the decision-making process or rely on your doctor's recommendation.

Key points in making your decision

Doctors can prescribe antiviral medicines that can help prevent the flu or help you fight it off after you have it.

Consider the following when making your decision:

• Most healthy adults who get the flu don't need an antiviral medicine. Taking an antiviral may be a good idea if you are at high risk for serious problems (complications) from the flu.
• Antiviral medicines can shorten the course of the flu but only by about 1 day. And you need to take the medicine within 2 days of getting sick for it to work.
• Antivirals can help control flu outbreaks in settings where people are at high risk of complications, such as nursing homes. If you live or work in such a setting during an outbreak, you should take an antiviral medicine, even if you got a flu shot in the fall.
• Experts don't know if antivirals are safe during pregnancy. If you are pregnant or breast-feeding and you are at risk for the flu, ask your doctor to help you weigh the benefits and risks of taking an antiviral medicine. And ask your doctor if you should get a flu shot.
• Antivirals do not take the place of flu shots. The best way to avoid getting the flu is to get a flu shot each fall.

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 pneumonia.

There are two types of antiviral medicines for the flu:

• Neuraminidase inhibitors, which include oseltamivir (Tamiflu) and zanamivir (Relenza)
• M2 inhibitors, which include amantadine (Symadine, Symmetrel) and rimantadine (Flumadine)

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 together.

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 complications.
• 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?

People who have serious breathing problems, such as asthma or COPD, should not use Relenza.

Some 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 shot.

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 Tamiflu).
• Relenza may cause breathing problems in people who have serious lung problems.
• Tamiflu may increase the risk for self-injury and confusion in people who have the flu, especially children. They 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 treat.

If you need more information about the flu, see the topic Influenza.

Your choices are:

• Take antiviral medicine to treat or prevent the flu.
• Do not take antiviral medicine.

The decision whether to take antiviral medicine takes into account your personal feelings and the medical facts.

These personal stories may help you make your decision.

Use this worksheet to help you make your decision. After completing it, you should have a better idea of how you feel about taking antivirals for flu. Discuss the worksheet with your doctor.

Circle the answer that best applies to you.

*NA=Not applicable

Use the following space to list any other important concerns you have about this decision.

What is your overall impression?

Your answers in the above worksheet are meant to give you a general idea of where you stand on this decision. You may have one overriding reason to take or not take antiviral medicine for the flu.

Check the box below that represents your overall impression about your decision.

Return to the topic Influenza.

Organization

Citations

1. Centers for Disease Control and Prevention (2006). CDC Health Alert: CDC Recommends Against the Use of Amantadine and Rimantadine for the Treatment or Prophylaxis of Influenza in the United States During the 2005–06 Influenza Season. Available online: http://www.cdc.gov/flu/han011406.htm.

Other Works Consulted

• Centers for Disease Control and Prevention (2006). Prevention and control of influenza: Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR, 55(RR-10): 1–44. Also available online: http://www.cdc.gov/mmwr/preview/mmwrhtml/rr55e628a1.htm. [Erratum: (2006). MMWR, 55(RR-10): 743. Also available online: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5529a4.htm.]

Author:	Sydney Youngerman-Cole, RN, BSN, RNC	Last Updated: September 29, 2006
Medical Review:	Adam Husney, MD - Family Medicine W. David Colby IV, MSc, MD, FRCPC - Infectious Disease
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