AVAILABILITY
5 mg/Rotadisk blister

ACTIONS/THERAPEUTIC EFFECTS
Zanamivir is an inhibitor of the influenza A and B viral enzyme and does not permit the release of newly formed virus from the surface of the infected cells. The inhibition of the viral neuroaminidase enzyme prevents the viral spread across the mucus lining of the respiratory tract, and inhibits the replication of influenza A and B virus.

USES
Uncomplicated acute influenza in patients symptomatic <2 d.

ROUTE & DOSAGE
Acute Influenza
Adult: Inhaled 2 inhalations (one 5 mg blister/inhalation) b.i.d. (approximately 12 h apart) x 5 d.

PHARMACOKINETICS
Absorption: 4-17% of inhaled dose is systemically absorbed. Peak: 1-2 h. Distribution: <10% protein bound. Metabolism: Not metabolized. Elimination: Half-life 2.5-5.1 h; excreted in urine.

ADMINISTRATION
Inhalation

• Initiate within 48 h of onset of flu symptoms.
• Give scheduled inhaled bronchodilator before zanamivir.
• Store at 25°C (77°F).

PRECAUTIONS Concurrent use of inhaled medication with inhaled zanamivir; pregnancy (category B); lactation. Safety & efficacy in children <12 y are unknown.

ADVERSE EFFECTS
Body as Whole: Headache. CNS: Dizziness. GI: Nausea, diarrhea, vomiting. Respiratory: Nasal symptoms, bronchitis, cough, sinusitis; ear, nose, throat infection.

NURSING IMPLICATIONS
Assessment & Drug Effects

• Therapeutic effectiveness: Indicated by relief of flu symptoms.

• Start within 30 h of onset of flu symptoms for most effective response.
• Use any scheduled inhaled bronchodilator first; then use zanamivir.
• Do not breast feed infants while taking this drug.

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