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Related to zanamivir: amantadine, Oseltamivir, Relenza


an inhibitor of viral neuraminidase used for the prophylaxis and treatment of influenza A and influenza B; administered by inhalation.



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.


An agent that inhibits neuraminidase of influenza virus.


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


An antiviral drug, C12H20N4O7, that is used in inhalant form for the treatment and prevention of influenza.


an antiviral administered by oral inhalation.
indication Zanamivir is used in the treatment and prophylaxis of type A and B influenza in patients who have had symptoms for no more than 2 days.
contraindication Known hypersensitivity to this drug prohibits its use.
adverse effects Adverse reactions to this drug include fatigue, ear-nose-throat infections, diarrhea, nasal symptoms, cough, sinusitis, and bronchitis. Common side effects include headache, dizziness, nausea, and vomiting.


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


A neuraminidase inhibitor antiviral drug used for the treatment of influenza A and influenza B. To be effective, the drug must be taken within 48 hours of the onset of symptoms. It is liable to cause tightening of the bronchial tubes and this may be dangerous in people with ASTHMA. A brand name is Relenza.
References in periodicals archive ?
Recommended dosage of antiviral agents for treatment Age group Weight (kg) Oseltamivir Zanamivir dosage * dosage * Adults 75 mg twice per Two 5 mg day inhalations (10 mg total) twice per day Premature neonates ([dagger]) <38 weeks 1 mg/kg twice per day 38-40 weeks 1.
Detection of resistance mutations to antivirals oseltamivir and zanamivir in avian influenza A viruses isolated from wild birds.
Intravenous zanamivir became available on a compassionate use basis during the pandemic.
He says that Oseltamivir (Tamiflu of Roche and Antiflu of Cipla) or Zanamivir (Relenza of Roche and Virenza of Cipla) are taken for the treatment and/or prevention of H1N1 viruses.
The country is in the process of acquiring the drug zanamivir, marketed by GlaxoSmithKline as Relenza.
Moreover, a person only should take an antiviral, such as oseltamivir or zanamivir, on the advice of a health care provider.
H1N1 is susceptible to oseltamivir and zanamivir and resistant to amantadine and ramantadine.
The DH guidance advises that some antiviral drugs are not recommended for pregnant women, and that zanamivir (Relenza) is the best course of treatment.
Testing has shown the antiviral drugs oseltamavir (Tamiflu) and zanamivir (Relenza) appear to be effective against the H1N1 strain.
Relenza, known generically as zanamivir, and Tamiflu, or oseltamivir, both appear to work against the new flu strain, which has spread to the United States and as far as New Zealand.
However, testing has shown that the antiviral drugs oseltamavir (Tamiflu) and zanamivir (Relenza) appear to be effective against the human swine influenza H1N1 strain, Why should we be worried about it?