According to the Centers for Disease Control and Prevention (CDC), most people with swine flu do not require treatment. Exceptions include people who are very sick and people in certain high-risk groups. There are two drugs, Tamiflu and Relenza, that are FDA-approved to treat swine flu. They should be taken before or as soon as symptoms appear.
How Tamiflu and Relenza Work
Introduced in 1999, both Tamiflu and Relenza are classified as neuraminidase inhibitors. According to a 2009 article in the "British Medical Journal," they prevent the action of an enzyme called neuraminidase that allows the influenza virus to escape from a person's cells after it has replicated. When taken before the onset of symptoms (prophylaxis), these drugs can prevent the virus from ever taking hold in your body. When taken after the onset of symptoms, the drugs can stop the virus from replicating, preventing your symptoms from getting worse and, according to the CDC, decreasing the duration of illness by one or two days. Although resistance to the medications is rare, resistance to one drug almost always means resistance to both because they work the same way.
Tamiflu
Tamiflu (oseltamivir phosphate) is available as 30, 45 and 75 mg capsules and a 12 mg/mL oral suspension suitable for children or people who have trouble swallowing the capsule. In adults, the standard dose is 75 mg twice daily for five days for the treatment of swine flu and 75 mg once daily for 10 days for the prevention of swine flu. The drug is cleared by the kidneys, so people with certain kinds of kidney problems should follow a decreased dosing schedule. In children, dosing is weight based and doses range from 30 to 75 mg, administered according to the same schedule used in adults. Longer courses may be used for the treatment of people who are hospitalized for swine flu.
According to MedlinePlus, the FDA granted emergency approval for the use of Tamiflu in the treatment and prevention of swine flu in children under age 1. Tamiflu is the only antiviral drug for swine flu that is approved for all ages. (For seasonal flu, Tamiflu is approved only in people over the age of 1.) In clinical studies by Roche Laboratories, the most common side effects of Tamiflu were nausea (10 percent) and vomiting (9 percent), usually during the first two days of taking the drug. These side effects can be reduced or avoided by taking the medication on a full stomach.
Relenza
Relenza (zanamivir inhalation) is dispensed as a 5 mg powder-filled blister or "Rotadisk." The contents of the Rotadisk are inhaled through the mouth using an included plastic inhaler called a "Diskhaler." Patients with asthma are advised to take Relenza after any prescribed bronchodilator medications. The standard dose for the treatment of swine flu is 10 mg (two Rotadisks) twice daily for five days. The standard dose for prophylaxis of swine flu is 10 mg (two Rotadisks) once daily for 10 days (household settings) or 28 days (community settings). Household settings apply when a person's family members or close contacts are sick. Community settings apply when there is an epidemic in a person's community. Although epidemics may last longer than 28 days, the safety and efficacy of using Relenza for longer periods of time has not been established. Relenza is approved for the treatment of swine flu in adults and children older than 7 and for swine flu prophylaxis in adults and children older than 5. The dose is the same for everyone.
Relenza contains lactose, a component of milk, and it is contraindicated in people with milk allergies. Relenza has also been associated with serious, sometimes fatal cases of airway constriction, so it should not be taken by people with a history of underlying lung or heart disease. In clinical studies by GlaxoSmithKline, the most common side effects of Relenza included inflammation of the sinuses and dizziness in people using Relenza for the treatment of swine flu and fever and/or chills and joint pain in people using Relenza for the prevention of swine flu. Similar symptoms were reported by patients who received a placebo; however, they were approximately 1.5 percent more common in people who received Relenza.
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
- Tamiflu: Tamiflu Prescribing Information
