LAS VEGAS -- Doctors in Nevada and across the country are trying to get the word out that people don't need antibiotics every time they get the sniffles or a sore throat. In fact, the CDC says overuse of antibiotics is causing resistant bacteria to multiply and make people sicker.

Loyola University infectious-disease specialist Dr. Gail Reid says many people don't realize how dangerous it can be to misuse antibiotics. She says people sometimes don't finish their medications, and then try to use them for another illness, even if the drugs have expired.

"Not only may it not work or be effective. It may actually cause bad side effects. Certain tetracyclides, if they are out of date and you use them, you can have serious complications."

Dr. Reid says people don't need to take antibiotics for most sore throats, colds and even bronchitis. They usually go away on their own. The CDC says that overuse of antibiotics in animals also contributes to the proliferation of so-called "superbugs."

If your doctor says you do need antibiotics, Dr. Reid says to be sure to tell the physician about all the medications you take. She warns that a woman could end up with an unplanned pregnancy after treatment for a urinary tract infection.

"Most of the time, when people prescribe Cipro or one of its relatives, they probably don't ask the young woman if she's on birth control. And it actually can impair the function or efficacy of their birth control."

The CDC advises doctors to write out suggested over-the-counter treatments for people who don't need antibiotics but insist that their doctors "do something." The agency says Americans spend more than $1 billion a year on antibiotics they don't need.

More information is at www.cdc.gov.