Zanamivir

Medically reviewed by Drugs.com. Last updated on Feb 2, 2022.

Commonly used brand name(s)

In the U.S.

• Relenza

Available Dosage Forms:

• Disk

Therapeutic Class: Antiviral

Pharmacologic Class: Neuraminidase Inhibitor, Influenza A&B Virus

Uses for zanamivir

Zanamivir belongs to the family of medicines called antivirals, which are used to treat infections caused by viruses. Zanamivir is used in the treatment of the infection caused by the flu virus (influenza A and influenza B). Zanamivir may also be used to prevent and treat swine influenza A.

Zanamivir may reduce flu symptoms (weakness, headache, fever, cough, runny or stuffy nose, and sore throat) by 1 to 1.5 days. Zanamivir may also be used to prevent influenza infection if you have come into close contact with someone who has the flu.

Zanamivir must be started within 2 days of having flu symptoms. Zanamivir will not keep you from spreading the flu virus to other people. It may not work for everybody. Zanamivir may not be for you if you are severely sick or have a breathing problem (e.g., asthma or chronic obstructive pulmonary disease). If you receive the flu vaccine every year, continue to do so. Zanamivir is not a substitute for your yearly flu shot.

Zanamivir is available only with your doctor's prescription.

Before using zanamivir

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For zanamivir, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to zanamivir or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Appropriate studies have not been performed on the relationship of age to the effects of zanamivir for the treatment of influenza in children younger than 7 years of age and for the prevention of influenza in children younger than 5 years of age. Safety and efficacy have not been established in these age groups.

Note: Zanamivir is available in Canada. It is not recommended in children younger than 12 years of age.

Geriatric

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of zanamivir in the elderly. However, elderly patients may be more sensitive to the effects of zanamivir than younger adults, which may require caution in patients receiving zanamivir.

Breastfeeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

Interactions with food/tobacco/alcohol

Certain medi...