Zannamivir

Indications

Zannamivir is used for: Prophylaxis & treatment of Influenza A and B virus infection

Adult Dose

Inhalation Influenza A and B Adult: 10 mg (2 inhalations) bid for 5 days, admin as soon as possible (within 48 hr) after the onset of symptoms. 2 doses should be taken on 1st day of treatment provided there is at least an interval of at least 2 hr between doses, subsequent doses to be given every 12 hr. Prophylaxis of influenza A and B Adult: For community outbreak: 10 mg (2 inhalations) once daily for 28 days, to be started within 5 days of outbreak. For prophylaxis in household setting: 10 mg (2 inhalations) once daily for 10 days, to be started within 36 hr of exposure.

Child Dose

Inhalation Influenza A and B Child: >7 yr: 10 mg (2 inhalations) bid for 5 days, admin as soon as possible (within 48 hr) after the onset of symptoms. 2 doses should be taken on 1st day of treatment, if possible, provided there is at least an interval of at least 2 hr between doses, subsequent doses to be given every 12 hr. Inhalation Prophylaxis of influenza A and B Child: For community outbreak: >12 yr: 10 mg (2 inhalations) once daily for 28 days, started within 5 days of outbreak. For prophylaxis in household setting: ?5 yr: 10 mg (2 inhalations) once daily for 10 days, to be started within 36 hr of exposure.

Renal Dose

Administration

Contra Indications

Hypersensitivity.

Precautions

Pregnancy, lactation. High risk of bronchospasm in chronic respiratory diseases. Fast-acting bronchodilator should be readily available for asthma/COPD patients; avoid in severe asthma. Bronchodilators to be inhaled before zanamivir admin. Discontinue if bronchospasm develops or there is decrease in respiratory function.

Pregnancy-Lactation

Interactions

Do not admin live attenuated influenza vaccine intranasal within 2 wk before or 48 hr after zanamivir admin to improve response to vaccine.

Adverse Effects

Side effects of Zannamivir : >10% Headache (13-24%),Throat/tonsil pain (8-19%),Cough ( 7-17%),Viral infection (3-13%) >1% Dizziness (2%),Nausea (3%),Diarrhea (3% adults, 2% children),Vomiting (1% adults, 2% children),Sinusitis (3%),Bronchitis (2%),Infection (ear, nose, & throat; 2% adults, 5% children) <1% Malaise,Fatigue,Fever,Abdominal pain,Myalgia,Arthralgia,Urticaria

Mechanism of Action

Zanamivir, a sialic acid derivative, potentially inhibits viral neuraminidase of influenza virus, thus altering virus particle aggregation and release. It is active against influenza A and B virus replication.