zanamivir

zanamivir /za·nam·i·vir/ (zah-nam´i-vir) an inhibitor of viral neuraminidase used for the prophylaxis and treatment of influenza A and B.

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zanamivir

Relenza

Pharmacologic class: Neuraminidase inhibitor

Therapeutic class: Antiviral

Pregnancy risk category C

Action

Inhibits influenza virus neuraminidase, an enzyme essential for viral replication

Availability

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

Contraindications

• Hypersensitivity to drug or its components

Precautions

Use cautiously in:
• chronic obstructive pulmonary disease, asthma, lactose intolerance
• pregnant or breastfeeding patients
• children younger than age 7 (safety not established).

Administration

• 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.

Route	Onset	Peak	Duration
Inhalation	Rapid	1-2 hr	12 hr

Adverse reactions

CNS: headache, dizziness

EENT: sinusitis, EENT infections

GI: nausea, vomiting, diarrhea

Respiratory: bronchitis, cough

Other: allergic reaction

Interactions

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's 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.

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zanamivir Relenza^® Infectious disease An inhaled viral neuraminidase inhibitor used to treat and prevent influenza A and B infection. See Influenza. Cf Amantadine, Rimantidine.