Influenza A is treated with a combination of prescription antiviral medications and at-home symptom management. Most people recover within five to seven days, but the speed and severity of your illness depend heavily on how quickly you start treatment. Antivirals work best when taken within the first 48 hours of symptoms.
Antiviral Medications
Four FDA-approved antiviral drugs are currently recommended for treating influenza A in the United States. The most commonly prescribed is oseltamivir (Tamiflu), an oral medication taken twice daily for five days. It’s available as both a pill and a liquid, making it practical for adults and young children alike. It’s approved for patients as young as 14 days old.
Baloxavir (Xofluza) offers a simpler option: a single oral dose, taken once, and you’re done. It’s approved for adults, children 12 and older, and children ages 5 to 11 without chronic medical conditions. For people who want the convenience of one-and-done treatment, this is the most straightforward choice.
Two other options exist for specific situations. Zanamivir (Relenza) is an inhaled medication taken twice daily for five days, approved for ages 7 and up. It’s not recommended for anyone with asthma or chronic lung disease, since it can trigger breathing problems. Peramivir (Rapivab) is given as a single IV infusion, typically in a clinic or hospital setting, and is approved for patients 6 months and older.
Why the First 48 Hours Matter
Antiviral medications work by interfering with the flu virus’s ability to replicate inside your body. The earlier you start them, the less time the virus has to multiply and cause damage. Starting treatment within 48 hours of your first symptoms shortens the duration of illness and reduces the risk of serious complications like pneumonia.
If you fall into a high-risk group (more on that below), antivirals can still be beneficial even if you’re past the 48-hour window. But for the best outcome, contact a healthcare provider as soon as flu symptoms appear: sudden fever, body aches, chills, cough, sore throat, and fatigue that hits all at once rather than building gradually.
Managing Symptoms at Home
Whether or not you take an antiviral, symptom relief at home makes a real difference in how you feel during recovery. Acetaminophen (Tylenol) and ibuprofen (Advil, Motrin) both reduce fever and ease the muscle aches and headaches that make the flu so miserable. You can alternate between the two if one alone isn’t enough, since they work through different mechanisms.
One critical rule for children and teenagers: never give aspirin during a flu illness. Aspirin use during viral infections in young people is linked to Reye’s syndrome, a rare but potentially fatal condition that causes swelling in the liver and brain.
Staying Hydrated
Fever, sweating, and reduced appetite all pull fluid from your body faster than usual. Under normal conditions, the general recommendation is about 15 cups of fluid per day for men and 11 for women. During a high-fever illness, you need at least that much and often more. Water, broth, electrolyte drinks, and herbal tea all count. If nausea makes it hard to keep fluids down, take small sips of about an ounce every three to five minutes rather than trying to drink a full glass at once. This approach rehydrates you without overwhelming your stomach.
Rest and Recovery
Flu symptoms typically last five to seven days from the time they appear, with the worst of the fever and body aches concentrated in the first two to three days. Cough and fatigue often linger a bit longer, sometimes stretching into a second week. Plan on staying home and resting until your fever has been gone for at least 24 hours without fever-reducing medication. Pushing yourself back into normal activity too soon can slow your recovery and increase the chance of complications.
Treatment for High-Risk Groups
Certain people face a higher chance of flu complications and should start antiviral treatment as quickly as possible, regardless of how mild their symptoms seem at first. This includes adults 65 and older, children under 5 (especially those under 2), pregnant women, and anyone with chronic conditions like asthma, diabetes, or heart disease.
If you have diabetes, the flu can disrupt blood sugar levels in unpredictable ways. Following sick-day guidelines for your diabetes management plan is essential, and you should have at least a two-week supply of your regular medications on hand before flu season hits. The CDC recommends prompt antiviral treatment for all people with diabetes who develop flu symptoms.
People with asthma or chronic lung disease should be aware that zanamivir (the inhaled antiviral) is not a safe option for them. Oseltamivir or baloxavir are better choices. The flu itself can trigger severe asthma flares, so early treatment is especially important for this group.
Why Older Antivirals Are No Longer Used
You may come across references to an older class of flu drugs called adamantanes (amantadine and rimantadine). These are no longer recommended. Nearly all circulating influenza A strains have developed resistance to them, making them ineffective. The four currently recommended antivirals remain effective against the vast majority of seasonal flu strains, though resistance monitoring continues. A specific genetic mutation called H275Y can make certain H1N1 strains resistant to oseltamivir and peramivir, but this remains uncommon in circulating viruses.
Warning Signs That Need Immediate Attention
Most flu cases resolve on their own or with antiviral treatment, but some develop into emergencies. In adults, seek immediate care if you experience difficulty breathing or shortness of breath, persistent pain or pressure in the chest or abdomen, confusion or dizziness that won’t go away, seizures, inability to urinate, severe muscle pain, or a fever and cough that seem to improve but then return worse than before.
In children, the red flags include fast or labored breathing, ribs visibly pulling in with each breath, bluish lips or face, refusal to walk due to muscle pain, no urine output for eight hours, dry mouth with no tears when crying, or a fever above 104°F that doesn’t respond to medication. For infants under 12 weeks, any fever at all warrants immediate medical evaluation. A fever or cough in any child that improves and then worsens again can signal a secondary infection like pneumonia and needs prompt attention.