New Drugs Help Foil the Flu
Vaccination is still the best way we have of staving off influenza. Several new antiviral drugs on the market can also prevent the disease or help bring it under control. With winter flu season approaching, I think these medications merit some consideration.
The new drugs are not a substitute for getting a flu shot. But the Food and Drug Administration has approved some of them for preventing influenza during an outbreak. And, according to a recent study in Annals of Internal Medicine, they’re cost-effective in reducing symptoms and lost workdays if you do get the flu.
All About the Flu Influenza is caused by one of two types of flu viruses: A or B. Type A is most common and type B is generally less severe. The viruses usually strike between December and April. Since each type of flu virus has different strains, the flu is slightly different every year and can infect people several times during their lives.
The flu usually goes away on it’s own after a week or two. In the meantime, though, it may cause a lot of misery.
Common symptoms include:
Fever
Chills
Fatigue
Headache
Body Aches
Cough
Sore Throat
Stuffy Nose
Vomiting
Complications occasionally occur such as:
Pneumonia
Infection of the ears, sinuses, heart or brain
Worsening of chronic diseases
How the Drugs Help
Despite national vaccination efforts, the flu infects 20 million Americans each year, kills 20,000, and hospitalizes thousands more. Antiviral drugs can stymie the infection by blocking the ability of the flu virus to attack your cells. Studies show drug treatment can shorten the illness by an average of about a day or day and a half. So far there is no evidence, though, that the drugs are effective in preventing serious flu complications.
Here are the details on the four available drugs:
Amantadine (Symmetrel) – an oral medication that treats or prevents influenza A in people age one year or older. Side effects may include nervousness, trouble concentrating, dizziness and nausea.
Rimantadine (Flumadine) – an oral medication that treats influenza A in adults. It also prevents the disease in people age one year or older. Side effects may include anxiety, insomnia, nausea and loss of appetite.
Zanamivir (Relenza) – an inhaled drug that treats influenza A and B in people age seven or older. It’s not approved for prevention, though some studies suggest it might be effective. The drug is not recommended for people with asthma or chronic lung disease.
Oseltamivir (Tamiflu) – an oral medication that treats influenza A and B in people age one or older. It also prevents both diseases in people age 13 or older. Taking it with food may lessen potential side effects like nausea and vomiting.
Why Take the Drugs?
For Acute Flu Symptoms
Antiviral drugs are recommended for people at high risk for complications of the flu, as well as those with severe symptoms. They’re also an option for people who would like to shorten the length of time that they are sick.
Early diagnosis is key if you want to treat the flu with antiviral drugs. New rapid tests of the nose and throat can help distinguish influenza from similar diseases. When flu is present your doctor must give you the medication within two days of the onset of symptoms; otherwise, the drug won’t be effective.
For Preventing Flu
In certain situations your doctor may advise that you take a drug daily during flu season to reduce your risk of contracting the virus.
Candidates for preventive antiviral drug therapy include:
People at high risk for serious complications who have not been vaccinated
People at high risk who were vaccinated after the start of a flu outbreak Immune deficient people (in addition to getting a flu vaccine)
Vaccinated people at high risk when the vaccine virus and epidemic virus are a poor match.
Unvaccinated people caring for or living with people at high risk.
Residents and staff at long-term care facilities during an institutional outbreak
Household contacts during an outbreak in a family or home.
by Elizabeth Smoots, MD
Resources:
National Center for Infectious Diseases
National Institute of Allergy and Infectious Diseases
American Lung Association
Sources:
National Center for Infectious Diseases
Lee PY, Matchar DB, Clements DA, Huber J, Hamilton JD, Peterson, ED. Economic analysis of influenza vaccination and antiviral treatment for healthy working adults. Ann Intern Med. 2002; 137:225-231.
Prevention and control of influenza: recommendations of the advisory committee on immunization practices. MMWR. 2002;51:1-31.
Deasy J, Rosenber DJ. Influenza: New therapeutic and preventive strategies. Emergency Medicine. 2002;1:21-33.
Last reviewed October 2002 by HealthGate Editorial Staff
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