For influenza treatment, the only inhaler formulation approved for use is zanamivir, marketed as Relenza®.
Zanamivir (Relenza®): The Approved Inhaler for Influenza
When it comes to influenza treatment delivered via inhalation, zanamivir (Relenza®) stands out as the sole FDA-approved option among the various antiviral drugs. While there are several antiviral medications recommended for influenza, such as oseltamivir phosphate (Tamiflu®), peramivir (Rapivab®), and baloxavir marboxil (Xofluza®), only zanamivir is specifically formulated and approved for inhalation use.
Relenza is typically administered using a special device that allows the medication to be inhaled directly into the respiratory tract, where the influenza virus primarily replicates. This direct delivery mechanism can be beneficial for targeting the infection in the airways.
How Zanamivir Works
Zanamivir belongs to a class of antiviral drugs known as neuraminidase inhibitors. These drugs work by blocking the activity of neuraminidase, an enzyme found on the surface of the influenza virus. This enzyme is crucial for the virus to release new viral particles from infected cells and to spread throughout the respiratory tract. By inhibiting neuraminidase, zanamivir helps to prevent the spread of the virus within the body, thereby reducing the severity and duration of influenza symptoms.
Important Considerations for Influenza Treatment
It's important to note that antiviral medications for influenza, including zanamivir, are most effective when started early, ideally within the first 48 hours of symptom onset. They are primarily used for:
- Treatment: To lessen symptoms and shorten the duration of illness.
- Prevention: In some cases, to prevent influenza in people exposed to the virus, especially those at high risk of complications.
The decision to use an antiviral drug, and which one, depends on various factors, including the patient's age, underlying health conditions, and the severity of their illness. Always consult a healthcare professional for diagnosis and treatment recommendations.
Overview of FDA-Approved Influenza Antivirals
The table below summarizes the four main FDA-approved antiviral drugs recommended by the CDC for influenza treatment, highlighting which one is available as an inhaler.
| Drug Name | Brand Name(s) | Formulations Available | Approved for Inhalation? |
|---|---|---|---|
| Zanamivir | Relenza® | Inhalation powder | Yes |
| Oseltamivir Phosphate | Tamiflu® | Oral capsules, oral suspension | No |
| Peramivir | Rapivab® | Intravenous (IV) solution | No |
| Baloxavir Marboxil | Xofluza® | Oral tablets, oral suspension | No |
While multiple antiviral options exist for influenza, zanamivir remains the specific choice when inhalation delivery is required or preferred for treatment.
