Xofluza and Tamiflu are both indicated for acute influenza (flu) and for the prevention of flu following contact with a person who has the flu (post-exposure prophylaxis).

There are several differences between Xofluza (baloxavir marboxil) and Tamiflu (oseltamivir) including uses, dosing, how they work, and what they cost.

How do the uses and doses differ between Xofluza and Tamiflu?

The uses, doses and age ranges for Xofluza and Tamiflu are as follows:

Xofluza

• Xofluza (baloxavir marboxil) is given as single-dose, oral treatment for acute, uncomplicated influenza in otherwise healthy people 5 years and older, and in adults and children 12 years of age and older who are at high risk of developing complications from the flu. It should be taken within 48 hours of the start of flu symptoms.
• Xofluza is also used as a flu preventive in people who are at least 5 years old and who may have been exposed to flu but do not yet have symptoms.
• Xofluza is available as a tablet and as a liquid suspension.
• Do not take Xofluza with dairy products, calcium-fortified beverages, laxatives, antacids or oral supplements containing iron, zinc, selenium, calcium or magnesium due to possible drug interactions.

Tamiflu

• Tamiflu (oseltamivir) is also taken within 48 hours of flu symptom onset, but is taken twice a day for 5 days in a row to treat flu in people 2 weeks of age and older.
• Tamiflu is also used as a flu preventive in people who are at least 1 year old and who may have been exposed to flu but do not yet have symptoms.
• Tamiflu is available as a capsule and as a liquid suspension.
• There is less chance of stomach upset if you take Tamiflu with food.

How do Xofluza and Tamiflu work?

Both of these drug are considered antivirals that work against the influenza virus, but they do this in different ways:

• Xofluza works by blocking the cap-dependent endonuclease activity of the viral polymerase and prevents flu virus replication.
• Tamiflu is a neuraminidase enzyme inhibitor that frees viruses from the infected cells surface.
• Because Xofluza works with a new mechanism, theoretically it may be effective for viruses that have grown resistant to the antiviral action of Tamiflu.

What is the cost of Xofluza and Tamiflu?

• Xofluza costs over $150 for one treatment, according to Genentech, the drug’s manufacturer. If you have prescription insurance, your plan will most likely cover the costs of at least one flu drug, minus your copay or coinsurance. Genentech is also providing a coupon for patients with commercial insurance to lower the cost of Xofluza to $30.
  See Xofluza Prices, Coupons and Patient Assistance Programs
• Tamiflu is now available as a more affordable generic drug called oseltamivir. The cost of oseltamivir is roughly $50 to $60 for 10 capsules of the 75 mg dose using online coupons at your pharmacy. The cost for one 60 mL bottle of the 6 mg/mL oral oseltamivir suspension costs about the same.
  See Oseltamivir Prices, Coupons and Patient Assistance Programs
• The brand name Tamiflu runs about three times the cost of the generic, about $180 cash with online coupons, but this price may vary.
  See Tamiflu Prices, Coupons and Patient Assistance Programs

How do the side effects differ between Xofluza and Tamiflu?

• The most common side effects with Xofluza include diarrhea, bronchitis, nausea, sinusitis, and headache.
• The most common side effects of Tamiflu when used for treatment of the flu include nausea, vomiting, and headache.
• When used for prevention of the flu, Tamiflu side effects may also include nausea, vomiting, headache, as well as pain.