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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.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.



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.

McGraw-Hill Nurse's Drug Handbook, 7th Ed. Copyright © 2013 by The McGraw-Hill Companies, Inc. All rights reserved


An agent that inhibits neuraminidase of influenza virus.
Farlex Partner Medical Dictionary © Farlex 2012


An antiviral drug, C12H20N4O7, that is used in inhalant form for the treatment and prevention of influenza.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.


Relenza® Infectious disease An inhaled viral neuraminidase inhibitor used to treat and prevent influenza A and B infection. See Influenza. Cf Amantadine, Rimantidine.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.


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.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
References in periodicals archive ?
B/Quebec/1182C/2018 demonstrated reduced inhibition (RI; 5- to 50-fold increases in [IC.sub.50] over wild-type) (4) to oseltamivir, zanamivir, and peramivir, showing 5.97-, 32.44-, and 38.34-fold increases in [IC.sub.50]s, respectively, over B/Quebec/88855/2018 WT (Table).
A 2011 record linkage study in Sweden identified 86 pregnant women for whom oseltamivir (n=81) or zanamivir had been prescribed.
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 1.5 mg/kg twice per day Infants (14 3 mg/kg twice days--12 months) a day Children [less than 30 mg twice per Two 5 mg or equal day inhalations to] 15 kg (10 mg total) >15-23 kg 45 mg twice per twice per day day (only in >23-40 kg 60 mg twice per children aged day [greater than >40 kg 75 mg twice per or equal to] day 7 years) * Recommended duration of treatment is 5 days.
Although zanamivir tended to be well tolerated, oseltamivir was associated with an increased risk of nausea and vomiting, as well as a greater risk of psychiatric events when used as preventive therapy, the study found.
The meta-analysis also included five observational studies and two surveys that compared the second marketed neuraminidase inhibitor, inhaled zanamivir, with no antiviral therapy in patients treated as outpatients.
Antiviral treatment--typically oseltamivir (75 mg orally twice daily) or zanamivir (5 mg inhaled twice daily) for 5 days--should be administered promptly, ideally within 2 days of the onset of symptoms.
M2 PHARMA-January 20, 2011-GlaxoSmithKline begins Phase III study of IV zanamivir for hospitalised patients with influenza(C)2011 M2 COMMUNICATIONS
Dual treatment with oseltamivir and zanamivir was used when resistant virus was suspected or confirmed.
PREP Act declarations currently cover certain pandemic influenza countermeasures used to prevent, treat, or diagnose pandemic influenza such as influenza A (H1N1) 2009 monovalent vaccine, oseltamivir, zanamivir, peramivir, certain personal respiratory protection devices (e.g., N95 masks), certain respiratory support devices (e.g., mechanical ventilators), and certain diagnostic devices.