Swine flu is the common name for the novel H1N1 flu strain first identified by the Centers for Disease Control and Prevention (CDC) in April 2009. According to the CDC, antiviral drugs are prescription medications that fight against swine flu inside the body. The Food and Drug Administration has approved two antiviral drugs---Tamiflu and Relenza---for the treatment and prevention of swine flu.
Neuraminidase Inhibitors: How They Work
Tamiflu and Relenza are classified as "neuraminidase inhibitors" because, according to a 2009 article in the "British Medical Journal," they inhibit the enzyme neuraminidase that helps the influenza virus exit from host cells after it has replicated. The result is that virus replication is limited to just a few cells, limiting or even preventing the disease. According to the CDC, the drugs should be taken as soon as possible after the onset of swine flu symptoms. When taken within 48 hours, they decrease symptom severity and shorten the duration of disease by 1 or 2 days.
Tamiflu: Prescribing Information
Tamiflu (oseltamivir phosphate) is available as 30, 45 and 75 mg capsules and a 12 mg/mL oral suspension suitable for children and others who have trouble swallowing capsules. In adults, the standard dose is 75 mg twice daily for 5 days for the treatment of swine flu and 75 mg once daily for 10 days for the prevention of swine flu. In clinical studies conducted by Roche Laboratories, the most common side effects were nausea (10 percent) and vomiting (9 percent). Side effects usually occurred during the first 2 days of use and were reduced by taking the medication with food.
Relenza: Prescribing Information
Relenza (zanamivir inhalation) is dispensed as a 5-mg "Rotadisk" (powder-filled blister) that is inhaled through the mouth. A plastic inhaler called a "Diskhaler" is supplied for this purpose. Most patients require training on the proper use of the system. Relenza is FDA-approved for the treatment of swine flu in adults and children older than 7, as well as for swine flu prophylaxis in adults and children older than 5. Relenza sometimes causes airway spasms, so it should not be taken by people with a history of underlying heart or lung disease. In clinical studies, the most common side effects of Relenza included inflammation of the sinuses, dizziness, fever and/or chills and joint pain, reported by approximately 1.5 percent of patients.
References
- CDC: 2009 H1N1 and Seasonal Flu: What You Should Know About Flu Antiviral Drugs
- "British Medical Journal;" Neuraminidase Inhibitors for Preventing and Treating Influenza in Healthy Adults: Systematic Review and Metaanalysis; T. Jefferson, M. Jones, P. Doshi, and C. Del Mar; 2009
- GlaxoSmithKline: Relenza Prescribing Information
