Zanamivir
Mechanism :
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.
Indication :
- Treatment and prophylaxis for Influenza A and B.
Contraindications :
Hypersensitivity to zanamivir or any of the components.
Dosing :
Influenza A & B, Prophylaxis:
Household setting, >5 years: 10 mg inhaled once daily for 10 days; initiate within 48 hours of exposure.
Community outbreak, 12-16 years: 10 mg inhaled once daily for 28 days; initiate within 5 days of outbreak.
Influenza A & B, Treatment:
>7 years: 10 mg inhaled every 12 hourly for 5 days. Started within 2 days of symptom onset; administer 2 doses on day 1, at least 2 hours apart.
Adverse Effect :
Nasal symptoms, headache, dizziness, GI disturbances, cough, infection, rash, bronchitis. Rarely, hypersensitivity reactions, arrhythmias, bronchospasm, dyspnoea, facial oedema, seizures and syncope.
Interaction :
Administration of live attenuated influenza vaccine intranasally within 2 weeks before or 48 hr after zanamivir administration improves response to vaccine.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
| 20-50 | Dose as in normal renal function |
| 10-20 | Dose as in normal renal function |
| <10 | Dose as in normal renal function |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Unknown dialysability. Dose as in normal renal function |
| HD | Unknown dialysability. Dose as in normal renal function |
| HDF/High flux | Unknown dialysability. Dose as in normal renal function |
| CAV/VVHD | Unknown dialysability. Dose as in normal renal function |
Hepatic Dose :
No dose adjustment recommended.