Fighting the Flu: Do I Need an Antiviral Medication?
A flu shot is the best way to prevent the flu. But if you do come down with it, antivirals may help.
You can’t be cured of influenza (flu) once you get it. But there are prescription medications that may make the illness shorter and less severe. These are called flu antivirals.
Getting a flu shot each year is still the best way to prevent the flu. But there are some cases in which a flu antiviral may help.
Learn more about antivirals, when and how they are used, and whether they might be right for you.
What are flu antivirals?
Flu antivirals are medicines that interfere with the growth of flu viruses. Four antivirals are available, but these 2 are used most often and are most effective:
- Tamiflu (oseltamivir) can be used to treat or prevent flu in adults and children age 1 year and older.
- Relenza (zanamivir) can be used to treat adults and children age 7 years and older and to prevent flu in adults and children age 5 years and older. It should not be used by people who have asthma or other chronic lung problems because it can cause wheezing.
Two other antivirals – amantadine and rimantadine – have limited use because influenza A viruses are becoming resistant to these medications.
When are flu antivirals recommended?
It normally takes about 2 weeks for the flu shot to become effective once it is given. If there is an outbreak of flu during this time, flu antivirals can be given under certain circumstances for added protection.
Flu antivirals can also be given once a person has the flu to help treat the illness and prevent complications.
Antivirals are most often prescribed for:
- People who have the flu and are very sick, including people hospitalized with a confirmed case of the flu or a flu complication like pneumonia
- People at high risk for complications from the flu, including adults older than 65, pregnant women, and people who have chronic diseases
- Children who are getting the flu vaccine for the first time and have not had time to build up immunity
- People who live or work around people at high risk for flu complications
- People who have HIV or weak immune systems
- People who aren’t able to get a flu shot
Flu antivirals can also be given if it is found that the strain of flu in an area is different from the one covered by the vaccine.
Certain people should not take flu antivirals. These include:
- People who are allergic to these drugs or any of their ingredients.
- People who have asthma or other chronic lung problems should not take Relenza because it can cause wheezing.
What are the drawbacks of taking flu antivirals?
Some of the possible drawbacks of antivirals are:
- Side effects. Antivirals may cause side effects, such as nausea, vomiting, dizziness, and headache. A few people have more serious reactions, such as confusion and abnormal behavior. Tell your doctor right away if you have any problems after taking the medication.
- Drug resistance. Viruses can become resistant to antivirals. Using antivirals when they aren’t really needed makes it more likely that they won’t work when they are needed.
- Cost. Antivirals can be expensive, costing from $60 to over $100.
Should I take an antiviral?
Doctors prescribe flu antivirals to help treat or prevent the flu in certain people. Your doctor can assess your need for these medications and help you weigh the benefits and risks of these drugs.
If you’re considering an antiviral to treat the flu, keep in mind that:
- Taking an antiviral drug will only shorten your illness by about 1 day.
- Flu antivirals are most effective if taken within 2 days of the onset of flu symptoms. They are unlikely to help if taken later than this.
If you want to avoid the flu, get a flu shot. That’s your best bet for prevention.