Drug Groups

approved; investigational

Description

A guanido-neuraminic acid that is used to inhibit neuraminidase. [PubChem]

Indication

For the prevention and treatment of influenza A and B.

Pharmacology

Zanamivir, an antiviral agent, is a neuraminidase inhibitor indicated for treatment of uncomplicated acute illness due to influenza A and B virus in adults and pediatric patients 7 years and older who have been symptomatic for no more than 2 days. Zanamivir has also been shown to significantly inhibit the human sialidases NEU3 and NEU2 in the micromolar range (Ki 3.7 +/-0.48 and 12.9+/-0.07 microM, respectively), which could account for some of the rare side effects of zanamivir.

Affected Organisms

Biotransformation

Not metabolized

Absorption

Absolute bioavailability is very low following oral administration (2%). Following oral inhalation, bioavailability is 4% to 17%.

Half Life

2.5-5.1 hours

Protein Binding

Zanamivir has limited plasma protein binding (<10%).

Elimination

It is excreted unchanged in the urine with excretion of a single dose completed within 24 hours.
Unabsorbed drug is excreted in the feces.Zanamivir is renally excreted as unchanged drug.

Clearance

* 2.5 - 10.9 L/h [Following oral inhalation 10 mg]
* 5.3 L/h [Normal renal function receiving IV single dose of 4 mg or 2 mg]
* 2.7 L/h [Patients with mild and moderate renal impairement receiving IV single dose of 4 mg or 2 mg]
* 0.8 L/h [Patients with severe renal impairement receiving IV single dose of 4 mg or 2 mg]

References

External Links