Antiviral agent | Treatment dose | Prophylaxis dose | Contraindications |
Oseltamivir* | 75 mg orally twice daily for 5 days¶ | 75 mg orally once daily; usual duration 7 days*Δ | N/A |
Zanamivirפ | 10 mg (two 5 mg inhalations) twice daily for 5 days | 10 mg (two 5 mg inhalations) once daily; usual duration 7 days | Zanamivir (inhaled) is contraindicated in patients with asthma or chronic obstructive pulmonary disease, and it should not be used for treatment of severe influenza (given limited data). |
Peramivir* | 600 mg intravenously as a single dose¶¥ | N/A | Peramivir should be reserved for patients who cannot tolerate oral or inhaled agents. |
Baloxavir§‡ | 40 kg to <80 kg: 40 mg orally as a single dose ≥80 kg: 80 mg orally as a single dose | Postexposure prophylaxis: same dose as for treatment, single dose† | Baloxavir should not be used for treatment of severe influenza (given limited data), immunocompromised hosts (given concern for emergence of resistance), or pregnant patients (given limited data). |
* Dose reduction of oseltamivir and peramivir is recommended for patients with renal impairment.
¶ For patients with ongoing symptoms of severe lower respiratory tract disease (particularly in the setting of immunosuppression), an extended duration of antiviral treatment (up to 10 days) may be reasonable, particularly in those who continue to have detectable viral RNA from a respiratory specimen after 5 days of antiviral treatment.
Δ Longer courses may be warranted in the setting of institutional outbreaks. Refer to UpToDate topic on prevention of seasonal influenza for further discussion.
◊ Zanamivir is administered via oral inhalation by using a plastic device included in the package; patients will benefit from instruction and demonstration of the correct use of the device.
§ During outbreaks caused by oseltamivir-resistant influenza virus, zanamivir or baloxavir may be used. It is important to assess the risk of oseltamivir-resistant influenza before selecting an antiviral drug; clinicians should review regional influenza surveillance data to determine which influenza types and subtypes are circulating, as well as resistance patterns. This information is available via the United States Centers for Disease Control and Prevention website.
¥ If peramivir is used for treatment of severe influenza, we favor administration for 5 days[5].
‡ Coadministration of baloxavir with dairy products, calcium-fortified beverages, polyvalent cation-containing laxatives, antacids, or oral supplements (eg, calcium, iron, magnesium, selenium, zinc) should be avoided.
† Baloxavir is US Food and Drug Administration approved for postexposure prophylaxis but not for pre-exposure prophylaxis.Do you want to add Medilib to your home screen?