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Zanamivir Dosage

Medically reviewed by Drugs.com. Last updated on Oct 4, 2022.

Applies to the following strengths: 5 mg

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.

Further information

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