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Pharmacologic class: Neuraminidase inhibitor

Therapeutic class: Antiviral

Pregnancy risk category C


Inhibits influenza virus neuraminidase, an enzyme essential for viral replication


Powder for inhalation: 5 mg/blister

Indications and dosages

Prevention of influenza

Adults and children ages 5 and older: Prophylaxis in the household setting, 2 inhalations (10 mg) once daily for 10 days. Prophylaxis during community outbreaks, 2 inhalations (10 mg) once daily for 28 days.

Influenza virus A or B

Adults and children ages 7 and older: Two oral inhalations (5 mg/inhalation) b.i.d. for 5 days


• History of allergic reaction to components of drug, including lactose milk proteins


Use cautiously in:

• chronic obstructive pulmonary disease, asthma, lactose intolerance

• concurrent use of live attenuated intranasal influenza vaccine (Don't administer until 48 hours after cessation of zanamivir and don't administer zanamivir until 2 weeks after administration of live attenuated influenza vaccine, unless medically indicated.)

• pregnant or breastfeeding patients

• children younger than age 7 (safety not established).


• Give two doses on day 1, spaced at least 2 hours apart. On subsequent days, space doses 12 hours apart, and give at approximately same time each day.

Adverse reactions

CNS: headache, dizziness

EENT: sinusitis, EENT infections

GI: nausea, vomiting, diarrhea

Respiratory: bronchitis, cough

Other: allergic reaction


None significant

Patient monitoring

• Assess respiratory status. Watch closely for signs and symptoms of declining respiratory function.

Patient teaching

• Explain therapy to patient. Demonstrate how to use Diskhaler device.

• Tell patient to take drug exactly as prescribed for as long as directed, even if symptoms improve.

• If patient is also taking an inhaled bronchodilator, advise him to take bronchodilator before zanamivir.

• Emphasize that drug doesn't prevent spread of influenza to others.

• Instruct patient to immediately report worsening respiratory symptoms.

• As appropriate, review other significant adverse reactions.


(za-na-mi-veer) ,


(trade name)


Therapeutic: antivirals
Pharmacologic: neuraminidase inhibitors
Pregnancy Category: C


Treatment of uncomplicated acute illness caused by influenza virus in patients ≥7 yr who have been symptomatic ≤2 days.Prevention of influenza in patients ≥5 yr.


Inhibits the enzyme neuramidase, which may alter virus particle aggregation and release.

Therapeutic effects

Reduced duration or prevention of flu-related symptoms.


Absorption: 4–17% of inhaled dose is systemically absorbed.
Distribution: Unknown.
Protein Binding: <10%.
Metabolism and Excretion: Mainly excreted by kidneys as unchanged drug; unabsorbed drug is excreted in feces.
Half-life: 2.5–5.1 hr.

Time/action profile (blood levels)

Inhalationrapid1–2 hr12 hr


Contraindicated in: Hypersensitivity to zanamivir or lactose.
Use Cautiously in: Chronic obstructive pulmonary disease or asthma (↑ risk of decreased lung function and/or bronchospasm); Obstetric / Lactation: Safety not established; Pediatric: Children <7 yr (for treatment) or <5 yr (for prophylaxis) (safety not established; may be at ↑ risk for neuropsychiatric events).

Adverse Reactions/Side Effects

Central nervous system

  • seizures (life-threatening)
  • abnormal behavior
  • agitation
  • delirium
  • hallucinations
  • nightmares


  • bronchospasm


  • allergic reactions


Drug-Drug interaction

None noted.



Inhalation (Adults and children ≥7 yr) 10 mg (given as 2 inhalations of 5 mg each) twice daily for 5 days.


Inhalation (Adults and children ≥5 yr) 10 mg (given as 2 inhalations of 5 mg each) daily for 10 days (for household setting) (28 days for community outbreaks).


Powder for inhalation: 5 mg/blister

Nursing implications

Nursing assessment

  • Assess patient for signs and symptoms of influenza (fever, headache, myalgia, cough, sore throat) before administration. Determine duration of symptoms. Indicated for patients who have been symptomatic for up to 2 days.
  • Determine if patient is lactose intolerant; may cause allergic reaction.

Potential Nursing Diagnoses

Risk for infection (Indications)


  • Consider available information on influenza drug susceptibility patterns and treatment effects before using zanamivir for prophylaxis.
  • Inhalation: Administer 2 doses on the first day of treatment whenever possible; must have at least 2 hours between doses. Doses should be administered 12 hr apart on subsequent days. Zanamivir is only for oral inhalation via DISKHALER; do not attempt via nebulization or mechanical ventilation.

Patient/Family Teaching

  • Instruct patient to use zanamivir exactly as directed and to finish entire course, even if feeling better.
  • Instruct patient in the use of the DISKHALER. Patient should read the accompanying Patient Instructions for Use.
  • Advise patients that zanamivir is not a substitute for a flu shot. Patients should receive annual flu shot according to immunization guidelines.
  • Patients with a history of asthma should be advised to have a fast-acting inhaled bronchodilator available in case of bronchospasm following zanamivir administration. If using bronchodilator and zanamivir concurrently, administer bronchodilator first.
  • Advise patients to report behavioral changes (hallucinations, delirium, and abnormal behavior) to health care professional immediately.
  • Inform patient that zanamivir does not replace flu shot. Flu shot should be taken according to instructions of health care professional.
  • Advise female patient to avoid zanamivir if pregnant or breast feeding.

Evaluation/Desired Outcomes

  • Reduced duration or prevention of flu-related symptoms.


A trademark for the drug zanamivir.


Zanamivir Infectious disease An neuraminidase inhibitor used to treat and prevent influenza A and B infection. See Influenza. Cf Amantadine, Rimantidine.
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