How Do Neuraminidase Inhibitors Work?

Neuraminidase inhibitors are antiviral drugs used to treat acute respiratory infections and influenza (a highly contagious viral infection that affects the respiratory system and is a major cause of morbidity and mortality).

All influenza viruses contain two glycoproteins, hemagglutinin, and neuraminidase (a protein essential for invading the new host cells). Neuraminidase inhibitors block the function of the viral neuraminidase protein, thus stopping the release of viruses from the infected host cells and preventing new host cells from being infected, and therefore, the infection does not spread in the respiratory tract.

The replication of the influenza virus reaches its peak between 24 to 72 hours after the onset of symptoms. Neuraminidase inhibitors should be given as early as possible (within 48 hours of symptom onset).

As neuraminidase inhibitors are effective against all strains of influenza and can be used as a prophylaxis (although not as a substitute for vaccination), they play a key role in the preparedness of epidemics and pandemics.

Neuraminidase inhibitors are used to treat:

• Influenza (A and B)
• As a treatment
• As a prophylaxis
• Viral pneumonia
• Swine flu
• Postexposure prophylaxis (within 7 days of exposure)
• Pre-exposure prophylaxis (at the time of community outbreaks)

Most of the minor side effects occur only once at the initiation of therapy and resolve within 1 to 2 days.

The common side effects include:

• Nausea
• Vomiting
• Abdominal pain
• Headache
• Dizziness
• Diarrhea
• Sinusitis (inflammation of the sinus cavities around the nose)

Other rare side effects include:

• Bronchospasm (reversible narrowing of the airways)
• Dysrhythmias (an abnormal rhythm in the electrical activity of the heart)
• Dyspnea (shortness of breath)
• Facial edema
• Rash
• Seizure (sudden uncontrolled electrical disturbance in the brain)
• Syncope (fainting or losing consciousness)
• Urticaria (a skin rash triggered by a reaction to food, medicine, or other irritants)
• Aggravation of diabetes
• Hepatitis (inflammatory condition of the liver)
• Confusion
• Toxic epidermal necrolysis (a rare and serious skin disorder)
• Unstable angina (new or worsening chest pain occurring at rest)
• Cough
• Renal impairment (poor function of the kidneys)

The information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Names of neuraminidase inhibitors include:

• Oseltamivir
• Peramivir
• Rapivab
• Relenza
• Tamiflu
• Zanamivir