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Relenza
zanamivir inhaled
Adult Dosing .
Dosage forms: DPI: 5 mg per blister
influenza A and B (seasonal flu) tx, uncomplicated
- [2 puffs inhaled q12h x5 days]
- Start: within 48h of symptom onset; Info: give 2 doses on Day 1 as long as >2h between doses; may extend tx if immunocompromised
influenza A and B (seasonal flu) prophylaxis
- [pre-exposure]
- Dose: 2 puffs inhaled q24h; Start: when influenza activity detected in community; Info: for patients at very high risk of developing complications who cannot receive influenza vaccine; give for duration of community influenza activity
- [post-exposure]
- Dose: 2 puffs inhaled q24h x7 days after last known exposure; Start: within 48h of exposure
- [community outbreak]
- Dose: 2 puffs inhaled q24h x28 days; Start: within 5 days of identified community outbreak
- [institutional setting]
- Dose: 2 puffs inhaled q24h for at least 14 days; Start: ASAP after identified outbreak; Info: give x7 days after last known case
renal dosing
- [no adjustment]
- renal impairment: no adjustment
- HD: no adjustment, on dialysis days administer after dialysis; consider supplement if next maintenance dose not due right after dialysis; PD: no adjustment; no supplement
hepatic dosing
- [not defined]
Peds Dosing .
- Dosage forms: DPI: 5 mg per blister
influenza A and B (seasonal flu) tx, uncomplicated
- [7 yo and older]
- Dose: 2 puffs inhaled q12h x5 days; Start: within 48h of symptom onset; Info: give 2 doses on Day 1 as long as >2h between doses; may extend tx if immunocompromised
influenza A and B (seasonal flu) prophylaxis
- [pre-exposure, 5 yo and older]
- Dose: 2 puffs inhaled q24h; Start: when influenza activity detected in community; Info: for patients at very high risk of developing complications who cannot receive influenza vaccine; give for duration of community influenza activity
- [post-exposure, 5 yo and older]
- Dose: 2 puffs inhaled q24h x7 days after last known exposure; Start: within 48h of exposure
- [community outbreak, adolescents]
- Dose: 2 puffs inhaled q24h x28 days; Start: within 5 days of identified community outbreak
- [institutional setting, 5 yo and older]
- Dose: 2 puffs inhaled q24h for at least 14 days; Start: ASAP after identified outbreak; Info: give x7 days after last known case
renal dosing
- [see below]
- renal impairment: no adjustment
- HD/PD: not defined, consider adult renal dosing for guidance
hepatic dosing
- [not defined]
Contraindications / Cautions .
- hypersensitivity to drug or ingredient
- hypersensitivity to milk protein
- patients unable to learn administration technique
- caution: asthma
- caution: COPD
Drug Interactions .
Overview
zanamivir
neuraminidase inhibitor
- impairs immunomodulatory viral infective agent
Monitor/Modify Tx
- influenza nasal vaccine, live
Adverse Reactions .
Serious Reactions
- bronchospasm
- anaphylaxis
- angioedema
- skin reaction, severe
- erythema multiforme
- Stevens-Johnson syndrome
- toxic epidermal necrolysis
- delirium
- hallucinations
- behavioral disturbance
- self-injury, including fatal
- arrhythmia
- syncope
- seizures
Common Reactions
- nausea
- dizziness
- headache
- bronchitis
- cough
- nasal symptoms
- ear infection
- nasal infection
- throat infection
- fever
- rigors
- malaise
- myalgia
- appetite changes
Safety/Monitoring .
Monitoring Parameters
no routine tests recommended
Pregnancy/Lactation .
Pregnancy
Clinical Summary
may use during pregnancy; risk of embryo-fetal toxicity not expected based on human data
Lactation
Clinical Summary
may use while breastfeeding; no human data available, though risk of infant harm not expected based on drug properties; no human data available to assess effects on milk production
Pharmacology .
Metabolism: for zanamivir: none; CYP450: none; Info: 4-17% systemic absorption
Excretion: for zanamivir: urine (100% unchanged), feces; Half-life: 2.5-5.1h, 18.5h (severe renal impairment)
Subclass: Influenza (Flu)
Mechanism of Action
for zanamivir: inhibits influenza neuraminidase
Formulary .
No Formulary Selected
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