Zanamivir Dosage

Medically reviewed by Drugs.com. Last updated on Oct 4, 2024.

Usual Adult Dose for Influenza

10 mg via oral inhalation twice a day for 5 days

Comments:

• This drug should be started within 48 hours after onset of symptoms.
• If possible, 2 doses should be taken on the first day, provided there are at least 2 hours between the doses.
• After the first day, doses should be about 12 hours apart (e.g., morning and evening) at about the same time each day.
• Safety and efficacy of repeated courses of therapy have not been studied.

Use: For the treatment of uncomplicated acute illness due to influenza A and B virus in patients symptomatic for no more than 2 days

Usual Adult Dose for Influenza Prophylaxis

10 mg via oral inhalation once a day

Duration of Therapy:

• Household setting: 10 days
• Community outbreak: 28 days

Comments:

• Dose should be administered at about the same time each day.
• Household setting: No data available on the efficacy of prophylaxis with this drug when started more than 1.5 days after onset of signs/symptoms in the index case.
• Community outbreak: No data available on the efficacy of prophylaxis with this drug when started more than 5 days after the outbreak was identified in the community.
• Safety and efficacy of prophylaxis with this drug not evaluated for durations exceeding 28 days.

Use: For prophylaxis of influenza

Usual Pediatric Dose for Influenza

7 years or older: 10 mg via oral inhalation twice a day for 5 days

Comments:

• This drug should be started within 48 hours after onset of symptoms.
• If possible, 2 doses should be taken on the first day, provided there are at least 2 hours between the doses.
• After the first day, doses should be about 12 hours apart (e.g., morning and evening) at about the same time each day.
• Safety and efficacy of repeated courses of therapy have not been studied.

Use: For the treatment of uncomplicated acute illness due to influenza A and B virus in patients symptomatic for no more than 2 days

Usual Pediatric Dose for Influenza Prophylaxis

5 years or older: 10 mg via oral inhalation once a day

Duration of Therapy:

• Household setting: 10 days
• Community outbreak: 28 days

Comments:

• Dose should be administered at about the same time each day.
• Household setting: No data available on the efficacy of prophylaxis with this drug when started more than 1.5 days after onset of signs/symptoms in the index case.
• Community outbreak: No data available on the efficacy of prophylaxis with this drug when started more than 5 days after the outbreak was identified in the community.
• Safety and efficacy of prophylaxis with this drug not evaluated for durations exceeding 28 days.

Use: For prophylaxis of influenza

Renal Dose Adjustments

No adjustment recommended.

Comments:

• Safety and efficacy not established in severe renal dysfunction.
• Due to low systemic bioavailability of this drug after oral inhalation, no dose adjustment needed with renal dysfunction; potential for drug accumulation should be considered.

Liver Dose Adjustments

Data not available

Precautions

CONTRAINDICATIONS:
History of allergic reaction to any of the ingredients, including milk proteins

Safety and efficacy for treatment and prophylaxis of influenza have not been established in patients younger than 7 and 5 years, respectively.

Consult WARNINGS section for additional precautions.

Dialysis

Data not available

Other Comments

Administration advice:

• The 10 mg dose is provided by 2 inhalations (one 5 mg blister per inhalation).
• For administration to the respiratory tract by oral inhalation only, using the included inhalation device
• Instruct patients/supervising adults in the use of the delivery system.
• Do not puncture any blisters of the drug until administering a dose using the included inhalation device.
• Consult the manufacturer product information regarding missed doses.

General:
Limitations of Use:

• This drug is not recommended for treatment or prophylaxis of influenza in patients with underlying airways disease (e.g., asthma, chronic obstructive pulmonary disease) due to risk of serious bronchospasm.
• This drug has not been proven effective for treatment in patients with underlying airways disease or as prophylaxis in nursing home residents.
• This drug is not a substitute for annual, early influenza vaccination as recommended by the US CDC Advisory Committee on Immunization Practices.
• As influenza viruses change over time, resistant or more virulent mutations may emerge and decrease the efficacy of antiviral drugs; available influenza drug susceptibility patterns and treatment effects should be considered when deciding whether to use this drug.
• No evidence of efficacy in any illness due to pathogens other than influenza virus A and B.

Monitoring:

• Psychiatric: For signs of abnormal behavior in patients with influenza
• Respiratory: Respiratory function in patients with underlying airways disease

Patient advice:

• Read the US FDA-approved patient labeling (Patient Information and Instructions for Use).
• Stop this drug and contact healthcare provider if respiratory symptoms increase during therapy (e.g., worsening wheezing, shortness of breath, other signs/symptoms of bronchospasm).
• If scheduled to use an inhaled bronchodilator at the same time as this drug, use the bronchodilator before using this drug.
• Watch for signs of unusual behavior; contact healthcare professional immediately if any signs of unusual behavior are seen.
• If prescribed for children, use only under adult supervision and instruction.
• Use of this drug for treatment of influenza has not been shown to reduce the risk of transmission of influenza to others.

See also:

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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