Do all flu drugs work against swine flu?

The prescription drugs Tamiflu (oseltamivir) and Relenza (zanamivir) are important treatments for the swine flu and are likely to reduce the flu's severity, if taken within 48 hours of appearance of symptoms, according to the Centers for Disease Control and Prevention. Be aware, though, that the current strain of swine flu is resistant to the two other approved antiviral drugs—amantadine and rimantadine.

Despite reports of some pharmacies in New York having already sold out of Tamiflu and Relenza, our medical advisors urge restraint before you consider taking either drug to prevent the virus. They are not a substitute for a vaccine. Although they are quite effective in preventing the flu once you have been exposed, (usually taken for ten days following exposure to a known case), if you take these drugs needlessly, you expose yourself to the side effects (see below) and potentially increase drug resistance to the flu, while reducing emergency supplies.

So, we advise against taking these drugs unless you know you have been in contact with someone who has been diagnosed, or you fit into one of the following groups:

• Children with chronic diseases, who have had close contact with someone diagnosed with swine flu.
• Travelers to Mexico who are: pregnant, children with chronic conditions, people 65 years and older and children younger than 5 years old.
• Healthcare workers who have come in contact with patients with swine flu and who have not used the usual, personal protective equipment available.

Remember, the reported cases of swine flu in the U.S. are still very, very small—fewer than 100 cases at press time. And to date, there is only a single case of a reported death in the U.S. linked to the virus.

If you experience the symptoms of swine flu head to the doctor for a quick test to determine if you have influenza A virus. If you test positive, further testing is necessary to confirm a diagnosis of swine flu. But your doctor can write a prescription, based on the initial quick test, for one of the two drugs depending on your age and how you prefer to take the drug. Tamiflu is used for any person age 1 year or older, and comes in capsule and liquid form. Relenza is an inhaled drug, and is approved to treat flu for anyone 7 years and older, and to prevent the flu for those 5 years and older.

The medications will often result in a milder case of swine flu and enable you to get better, faster. You are also more likely to avoid the serious complications associated with the flu. The drugs work best if taken them early in your illness, and may not be effective if you have been sick for longer than 48 hours.

Both medications can cause side effects—headache, nausea, and vomiting are reported to be the most common adverse effects with Tamiflu. And, you should know there have been reports of abnormal behavior from those taking these antivirals as well. Relenza can cause cough, as well as nasal and throat discomfort, and is not recommended for use in anyone with asthma or chronic obstructive pulmonary disease (COPD).

And finally, our medical advisors remind that the abrupt onset of symptoms like fever, dry cough and severe muscle aches are indicators of the flu, while sneezing, nasal congestion, a loose cough, and mild throat soreness are more likely due to an allergy or a viral respiratory infection such as a cold.

—Lisa Gill, editor, prescription drugs

Follow our continuing swine flu coverage and recommendations.