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Relenza (ZANAMIVIR)
Relenza works by blocking the neuraminidase enzyme, preventing the influenza virus from spreading and infecting new cells.
Relenza (ZANAMIVIR) is a small molecule neuraminidase inhibitor developed by Glaxosmithkline, targeting Sialidase 3 to treat influenza. It was FDA approved in 1999 and remains a branded product due to its off-patent status. Despite low bioavailability of 2%, its short half-life of 1.7 hours allows for effective treatment. Relenza is used to treat influenza, but its commercial status as an off-patent product limits its availability. Key safety considerations include its potential to cause respiratory issues and its inhaled administration method.
At a glance
| Generic name | ZANAMIVIR |
|---|---|
| Sponsor | GSK |
| Drug class | Neuraminidase Inhibitor [EPC] |
| Target | Sialidase 3 |
| Modality | Small molecule |
| Therapeutic area | Infectious Disease |
| Phase | FDA-approved |
| First approval | 1999 |
Mechanism of action
Zanamivir is an antiviral drug with activity against influenza virus [see Microbiology (12.4)].
Approved indications
- Influenza
Common side effects
- Viral respiratory infections
- Cough
- Ear, nose, and throat infections
- Malaise and fatigue
- Temperature regulation disturbances (fever and/or chills)
- Nausea and vomiting
- Diarrhea
- Nasal signs and symptoms
- Throat and tonsil discomfort and pain
- Nasal inflammation
- Muscle pain
- Feeding problems (decreased or increased appetite and anorexia)
Key clinical trials
- A/Texas Flu Challenge (PHASE1)
- A Phase 2 Trial Comparing Antiviral Treatments in Early Symptomatic Influenza (PHASE2)
- Zanamivir Treatment of Vascular Permeability in Dengue (ZAP-DENGUE) (PHASE2)
- Role of Neuraminidase Activity on Endothelial Dysfunction in Type 2 Diabetes (PHASE2)
- An Intravenous (IV) Zanamivir Pharmacokinetics (PK) Study in Hospitalized Neonates and Infants With Influenza Infection (PHASE2)
- Study to Assess Efficacy and Safety of Baloxavir Marboxil In Combination With Standard-of-Care Neuraminidase Inhibitor In Hospitalized Participants With Severe Influenza (PHASE3)
- A Study of Intravenous Zanamivir Versus Oral Oseltamivir in Adults and Adolescents Hospitalized With Influenza (PHASE3)
- A Study of Intravenous Zanamivir in the Treatment of Hospitalized Patients With Influenza Infection (PHASE3)
Primary sources
Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.
| Source | Used for |
|---|---|
| FDA label | Mechanism, indications, dosing, boxed warnings, drug interactions |
| ClinicalTrials.gov | Trial enrolment, design, endpoints, results |
Competitive intelligence
For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:
- Relenza CI brief — competitive landscape report
- Relenza updates RSS · CI watch RSS
- GSK portfolio CI