The treatment arsenal

There is no proven cure for colds or flu but time. However, over-the-counter medications are available to relieve the symptoms.

"OTC cough-cold products can make you more comfortable while you suffer," says Debbie Lumpkins, a scientist with the Food and Drug Administration's division of over-the-counter drug products. "They are intended to treat the symptoms of minor conditions, not to treat the underlying illness."

Don't bother taking antibiotics to treat your flu or cold; antibiotics do not kill viruses, and they should be used only for bacterial complications such as sinus or ear infections. Overuse of antibiotics has become a very serious problem, leading to a resistance in disease-causing bacteria that may render antibiotics ineffective for certain conditions.

Some dangers of OTC products

Children and teenagers with symptoms of flu or chickenpox should not take aspirin or products containing aspirin or other salicylates. Use of these products in young flu and chickenpox sufferers has been associated with Reye syndrome, a rare condition that can be fatal. Because cold symptoms can be similar to those of the flu, it's best not to give aspirin to people under 20 with these types of symptoms.

The active ingredients FDA considers safe and effective for relieving certain symptoms of colds or flu fall into the following categories:

Nasal decongestants open up the nasal passages. They can be applied topically, in the form of sprays or drops, or taken orally. But using sprays or drops longer than three days may cause nasal congestion to worsen.

Antitussives , also known as cough suppressants, can quiet coughs due to minor throat irritations. They include drugs taken orally, as well as topical medications like throat lozenges and ointments to be rubbed on the chest or used in a vaporizer.

Expectorants , taken orally, help loosen mucus and make coughs more productive.

Antihistamines: Until recently, another category of over-the-counter drugs called "antihistamines" was approved only for use by sufferers of hay fever and some other allergies. In October, clemastine fumarate, the active ingredient in products such as Tavist-1 and Tavist-D, was approved to treat cold symptoms. The effectiveness of other OTC antihistamines for this use is still being studied.

Most nonprescription cough-cold remedies contain a combination of ingredients to attack multiple symptoms. These combination products often contain antipyretics to reduce fever and analgesics to relieve minor aches, pains and headaches.

Users of OTC medicines should carefully follow the labeling instructions and warnings.

The Cold War

OTC cough and cold medication sales totaled 3.2 billion dollars in 1995, according to a national industry survey. That's no surprise, considering Americans endure about 1 billion colds each year.

Children get the most colds--six or eight a year. By contrast, adults average two to four a year, with a greater frequency in the parents of children.

The high rate in children is blamed on their lack of a built-up resistance to infection and the close contacts with other kids in schools and day care. Women's closer contact with children may also explain the greater prevalence of colds in women than in men.

Adults over 60 usually suffer less than one cold a year, probably because they have built up a natural immunity.

Most colds strike Americans in the fall and winter. Contrary to what many people believe, the increased rate of colds during this time is actually not due to the cold weather. So why do more people feel "under the weather" during the winter months? Probably, say researchers at NIH's National Institute of Allergy and Infectious Diseases, because of the greater time spent indoors in cold weather, increasing the opportunity for viruses to spread among people. Also, the lower humidity during the colder months helps cold-causing viruses to thrive and may dry the lining of the nasal passages, making them more susceptible to infection.

Because the symptoms of the common cold are caused by more than 200 different viruses--most by the so-called "rhinoviruses" (from the Greek rhin, meaning "nose")--the development of a vaccine isn't feasible. To minimize the spread of colds, people should try to keep their defenses up and their exposure down.

First line of defense

Cold viruses can be transmitted in one of two ways: by touching respiratory secretions on a person's skin (when shaking hands, for example) or on environmental surfaces (like doorknobs or handrails) and then touching the eyes, nose or mouth, or by inhaling infectious particles in the air (like respiratory secretions from a cough or sneeze).

The best way to break the chain of infection? Hand washing is the key, according to Iacuzio, along with not touching the nose, eyes or mouth.

"Your mucus membranes are your first line of defense against infection," according to Iacuzio. "Interference with the constant passage of mucus raises the chances for entry of the virus." That's why drinking liquids and maintaining a humid environment with a vaporizer may lower susceptibility.

To minimize the spread, other helpful measures include avoiding close, prolonged exposure to people with colds, and always sneezing or coughing into a facial tissue and immediately throwing it away. Cleaning environmental surfaces with a virus-killing disinfectant is also recommended.

The flu fighters

Flu typically affects 20 to 50 percent of the U.S. population each winter. It's a highly contagious disease, spreading mostly by direct person-to-person contact. "With the flu, coughing--even more than sneezing--is the most effective method of transmission," Iacuzio says.

The flu virus can linger in the air for as long as three hours. In close quarters, conditions are ripe for the spread of the virus. That explains why the highest incidence of the flu is in 5- to 14-year-olds, who spend much of their time in school, in close contact with their classmates. The most serious complications occur in older adults, however.

Years ago, there were no practical tools to protect people from flu. In 1918-1919, a global flu epidemic, or pandemic, struck half the world's population and claimed the lives of 20 million. Still today, 10,000 to 20,000 Americans--almost all of them elderly, newborns, or chronically ill--die each year from flu complications, usually pneumonia.

The challenge for scientists trying to protect us from the disease is that influenza viruses can change themselves, or mutate, to become different viruses. Scientists have classified flu viruses as types A, B and C. Type A is the most common and leads to the most serious epidemics. Type B can cause epidemics, but usually produces a milder disease than type A. Type C viruses have never been associated with a large epidemic.