Nurses Compass
Drug Guide
Zanamivir
Classification
Therapeutic: Antiviral for influenza
Pharmacological: Neuraminidase inhibitor
FDA Approved Indications
- Treatment of uncomplicated acute illness due to influenza A and B in patients aged 7 years and older
- Prophylaxis of influenza in individuals aged 5 years and older
Mechanism of Action
Zanamivir inhibits the influenza virus neuraminidase enzyme, preventing viral release from infected cells and limiting the spread of the virus within the respiratory tract.
Dosage and Administration
Adult: DPI (dry powder inhaler) inhalation: 10 mg (two inhalations) twice daily for 5 days for treatment; once daily for 10 days for prophylaxis.
Pediatric: Same as adult dosing for children aged 7 years and older.
Geriatric: No specific dosage adjustment needed, but assess lung function regularly.
Renal Impairment: Use caution; no specific dose adjustment recommended, but monitor renal function.
Hepatic Impairment: No specific dosing information available; use with caution.
Pharmacokinetics
Absorption: Well absorbed via inhalation.
Distribution: Primarily local action in respiratory tract; systemic absorption is minimal.
Metabolism: Minimal; excreted mostly unchanged.
Excretion: Renal excretion of unchanged drug.
Half Life: Approximately 2-3 hours.
Contraindications
- Hypersensitivity to zanamivir or excipients.
Precautions
- Use with caution in patients with chronic respiratory diseases (e.g., asthma, COPD) due to risk of bronchospasm.
- Assess for signs of allergic reactions.
Adverse Reactions - Common
- Headache (Common)
- Nasal congestion or sore throat (Common)
- Cough (Common)
Adverse Reactions - Serious
- Bronchospasm, wheezing in asthmatic or COPD patients (Serious but rare)
- Hypersensitivity reactions, including skin rash, allergic reactions (Rare)
Drug-Drug Interactions
- None significant reported
Drug-Food Interactions
- None
Drug-Herb Interactions
- None reported
Nursing Implications
Assessment: Assess lung function and respiratory status before and during therapy. Be alert for signs of bronchospasm.
Diagnoses:
- Ineffective airway clearance related to bronchospasm or airway obstruction.
Implementation: Instruct patient on proper inhaler technique. Monitor for adverse reactions.
Evaluation: Evaluate symptom relief and monitor for adverse reactions.
Patient/Family Teaching
- Use inhaler as directed, inhale deeply and hold breath for 10 seconds.
- Report any breathing difficulties or allergic reactions.
- Do not use for influenza prevention if not prescribed; only use for indicated prophylaxis or treatment.
Special Considerations
Black Box Warnings:
- None currently],
- genetic_factors':'None known.
- lab_test_interference':'None reported.'},
- overdose_management
- signs_symptoms":"Overdose unlikely but may include nausea, vomiting, dizziness." ,
- treatment":"Supportive care, monitor respiratory status, consult poison control if needed." ,
- storage_and_handling
- storage_conditions":"Store in a cool, dry place away from direct sunlight." ,
- stability":"Stable at room temperature for at least 2 years." ,
- references
- FDA Prescribing Information for Relenza, recent clinical guidelines on influenza management.
Genetic Factors: None known.
Lab Test Interference: None reported.
Overdose Management
Signs/Symptoms: Overdose symptoms may include nausea, vomiting, dizziness, or bronchospasm.
Treatment: Supportive care including airway management, monitoring, and symptomatic treatment. Consult poison control for guidance.
Storage and Handling
Storage: Store in a cool, dry place, protected from moisture and direct sunlight.
Stability: Stable for at least 2 years when stored properly.