Influenza (Flu) Treatment: Antivirals

Who Should Get Antiviral Drugs

People who are at high risk of serious complications from influenza may benefit most from antiviral medications. This includes: people 65 years of age and older, children 12-23 months of age, people with chronic medical conditions (e.g., heart or lung disease, diabetes), and pregnant women. (Note that none of the antivirals are approved for use in children less than 1 year of age.)

Although CDC has provided guidelines for health care professionals on the use of antiviral drugs, your doctor will decide whether you should receive antiviral drugs this season. The guidelines for use of influenza antivirals are not intended as recommendations for use of these medications in other situations, such as outbreaks of new strains of avian influenza.

For treatment: If you become sick with influenza-like symptoms this season, your doctor first may give you a test to find out whether you have influenza. Symptoms include fever (usually high), headache, tiredness, a sore throat and dry cough, nasal congestion, and body aches. Your doctor also will consider a number of factors before making a treatment decision, such as your risk for complications from influenza.

For prevention: In the event of an influenza outbreak in a home, institution, or community, your doctor may choose to prescribe antivirals to you as a preventive measure, especially if you are at high risk for complications from influenza. Also, if you are in close contact with someone who is considered at high risk for complications, you may be given antiviral drugs to reduce the chances of passing influenza to the high-risk person.

Side Effects

Amantadine and Rimantadine
Among some healthy adults and children, side effects can include central nervous system (CNS) side effects such as nervousness, anxiety, difficulty concentrating, and lightheadedness, and gastrointestinal side effects like nausea and loss of appetite. CNS side effects happen more often among persons taking amantadine than among persons taking rimantadine.

Among some other persons with long-term illnesses, more serious side effects, such as delirium, hallucinations, agitation, and seizures, can occur. Side effects usually diminish and disappear after 1 week.Zanamivir

This drug is inhaled and can cause side effects, especially in those with asthma or other chronic lung disease. Decreased respiratory function and bronchospasm have been reported with use of zanamivir. Zanamivir is generally not recommended for use in persons with underlying lung disease such as asthma and chronic obstructive pulmonary disease. Other side effects reported by less than 5% of those who have used this drug are diarrhea, nausea, sinusitis, nasal infections, bronchitis, cough, headache, and dizziness.

Oseltamivir
The side effects reported most often in those people who took this drug were gastrointestinal (i.e., nausea and vomiting). Nausea and vomiting may be less severe if oseltamivir is taken with food.