VIRENZA

Introduction

Virenza is a brand name for zanamivir, an antiviral medication used to treat and prevent influenza (flu) caused by influenza A and B viruses. It belongs to the class of neuraminidase inhibitors, which help stop the virus from spreading in the body.

Description

• Generic Name: Zanamivir

• Brand Name: Virenza (in some regions), Relenza (common brand)

• Dosage Form: Inhalation powder (via a Diskhaler device)

• Manufacturer: GlaxoSmithKline (GSK)

Use

Virenza is used for:

• Treatment of acute influenza (flu) in patients aged ≥7 years (must be started within 48 hours of symptom onset).

• Prevention of influenza in patients aged ≥5 years (post-exposure prophylaxis).

Mechanism of Action

• Zanamivir works by inhibiting neuraminidase, an enzyme on the surface of the influenza virus.

• This prevents the virus from being released from infected cells and spreading to new cells.

• It reduces the severity and duration of flu symptoms and helps prevent complications.

Side Effects

Common side effects:

• Headache

• Dizziness

• Nasal/throat irritation

• Cough

• Diarrhea, nausea

Serious side effects (rare):

• Allergic reactions (rash, swelling, difficulty breathing)

• Bronchospasm (wheezing, especially in asthma/COPD patients)

• Neuropsychiatric events (confusion, hallucinations – rare)

Storage

• Store at room temperature (15-30°C).

• Keep the powder in the original blister pack until use.

• Protect from moisture and light.

Precautions & Warnings

• Not recommended for people with asthma or COPD (risk of bronchospasm).

• Use with caution in patients with allergies to lactose or milk proteins (contains lactose carrier).

• Pregnancy & breastfeeding: Use only if clearly needed (consult a doctor).

• Avoid in severe kidney impairment (limited data on safety).

Conclusion

Virenza (zanamivir) is an effective antiviral for treating and preventing influenza when used early. It works by blocking viral spread but may cause respiratory irritation in some patients. Proper storage and adherence to usage guidelines are essential for effectiveness.