Doctors primarily prescribe antiviral medications for the flu, with oseltamivir (Tamiflu) being the most common choice for patients of all ages. These drugs work best when started within 48 hours of your first symptoms, so timing matters. Beyond antivirals, your doctor may also prescribe medications to manage specific symptoms like severe cough, and in some cases, antibiotics if a bacterial infection develops on top of the flu.
Antiviral Medications: The Main Treatment
Four FDA-approved antiviral drugs are currently used to treat influenza. They don’t cure the flu outright, but they shorten the illness, reduce symptom severity, and lower the risk of serious complications. All four are approved for treatment within two days of symptom onset.
- Oseltamivir (Tamiflu) is the first-line choice and the most widely prescribed. It’s a pill taken twice daily for five days. Adults take 75 mg per dose, while children’s doses are based on weight. It’s approved for anyone 14 days and older, and it’s the only antiviral the CDC recommends for hospitalized flu patients.
- Baloxavir (Xofluza) is a single-dose pill, which makes it the most convenient option. It works by blocking the flu virus from replicating in your upper respiratory tract, and virus levels drop rapidly after the dose. It’s approved for people aged 5 and older. Your dose depends on your weight: 40 mg if you’re under 176 pounds, 80 mg if you’re above.
- Zanamivir (Relenza) is an inhaled powder, taken as two inhalations twice daily for five days. It’s approved for ages 7 and up for treatment. Because it’s inhaled, it’s not a good fit for people with asthma or chronic lung disease.
- Peramivir (Rapivab) is the only antiviral given by IV infusion. It’s a single dose administered over at least 15 minutes, typically in a clinic or emergency room. This option exists mainly for people who can’t swallow pills or inhale medication.
For outpatients with uncomplicated flu, any of the four can be used depending on age and individual circumstances. But for anyone sick enough to be hospitalized, oseltamivir is the clear recommendation. The other three don’t have enough clinical data showing benefit in hospitalized patients.
The 48-Hour Window
Every flu antiviral is approved for use within two days of when symptoms start. This is the window where the drugs have the greatest impact on shortening your illness and preventing complications. If you’re in a high-risk group, your doctor may start treatment based on symptoms alone, without waiting for a flu test to come back positive.
That said, the CDC recommends that doctors not delay treatment for anyone who is hospitalized, has severe or worsening illness, or is at higher risk for complications. During flu season, especially when COVID-19 is also circulating, doctors are encouraged to start antiviral treatment empirically for these patients, meaning they prescribe it on suspicion rather than waiting for lab confirmation.
Who Gets Treated First
Doctors prioritize antiviral treatment for people most likely to develop dangerous complications. This includes pregnant women, young children, adults 65 and older, and people with chronic conditions like asthma, diabetes, heart disease, or weakened immune systems.
Pregnancy deserves special mention. Pregnant women are at significantly increased risk for flu complications, and antiviral treatment is recommended during any trimester, as well as up to two weeks postpartum. Oseltamivir is the preferred drug during pregnancy because it has the most safety data. Baloxavir is not recommended for pregnant or breastfeeding women due to a lack of safety studies. In some cases, doctors may consider a slightly higher oseltamivir dose during pregnancy because the body processes the drug differently, though this isn’t routine.
If you’re otherwise healthy and have mild symptoms, your doctor may still offer antivirals based on clinical judgment, particularly if you’re within that 48-hour window. But the urgency is highest for people in the priority groups listed above.
Prescription Cough Relief
The flu often brings a harsh, persistent cough that over-the-counter remedies barely touch. When coughing is severe enough to disrupt sleep or daily life, doctors sometimes prescribe benzonatate, a non-narcotic cough suppressant. It works directly on the lungs and breathing passages (and possibly the brain’s cough center) to quiet the cough reflex. The typical dose for adults and children 10 and older is 100 mg three times a day, with a maximum of 600 mg per day. It’s specifically indicated for coughs caused by colds and influenza.
In rare cases, doctors may prescribe codeine-containing cough syrups, though these are used more cautiously due to sedation and dependency concerns. Most of the time, benzonatate or supportive care is enough.
When Antibiotics Enter the Picture
Antibiotics don’t work against influenza. The flu is a viral infection, and antibiotics only kill bacteria. However, the flu can weaken your respiratory defenses enough that bacteria move in and cause a secondary infection, most commonly bacterial pneumonia, sinus infections, or ear infections.
If your symptoms start improving and then suddenly worsen, with a new or higher fever, worsening cough, or shortness of breath, that pattern often signals a secondary bacterial infection. At that point, your doctor will likely prescribe antibiotics to treat the bacterial problem, not the flu itself. Routine preventive antibiotics during the flu are not recommended because overuse contributes to antibiotic resistance. Antibiotics are reserved for when there’s a clear sign that bacteria have taken hold.
What You’ll Actually Experience
If you visit a doctor or urgent care with flu symptoms, here’s what typically happens. They may do a rapid flu test (a nasal swab with results in 15 to 30 minutes) or a more accurate molecular test. If the flu is suspected or confirmed and you’re within 48 hours of symptom onset, you’ll likely leave with a prescription for oseltamivir or baloxavir.
With oseltamivir, expect to take pills twice a day for five days. Many people notice their symptoms improving a day or two sooner than they would without treatment. Nausea is the most common side effect, and taking it with food helps. With baloxavir, you take a single dose and you’re done, which is a major advantage if you want simplicity.
Beyond the prescription, your doctor will likely recommend the same supportive measures you’ve heard before: fluids, rest, and over-the-counter pain relievers like acetaminophen or ibuprofen for fever and body aches. The antivirals handle the virus; everything else manages how you feel while your body finishes the fight.