Filed at 5:26 p.m. ET

WASHINGTON (AP) -- Cipro is not the only antibiotic that fends off anthrax. Two other drugs are widely available, have fewer side effects and are much cheaper, a message the government is struggling to get out.

The American Medical Association urged physicians Wednesday to quit prescribing unnecessary Cipro. Pediatric specialists warned that it is especially dangerous for parents to stockpile because Cipro is not approved for children's use.

The Centers for Disease Control and Prevention will produce a special Webcast Thursday to teach thousands of local doctors how to recognize anthrax and properly treat people exposed to the bacteria.

And the Food and Drug Administration announced it is about to issue specific instructions on how to use two other widely available antibiotics -- doxycycline and penicillin -- to prevent anthrax infection.

``It seems as if in the minds of some people, that's the only drug,'' FDA drug chief Dr. Janet Woodcock said, speaking of Cipro. ``That actually isn't the case.''

Only people who have been exposed to anthrax are supposed to take the 60-day course of antibiotics to prevent infection. Doctors should not give patients any antibiotic to keep in case they're exposed, the AMA stressed Wednesday.

There is a ``real risk that symptoms not related to anthrax will prompt people to initiate unnecessary treatment,'' said AMA chairman Dr. Timothy Flaherty.

A person who takes antibiotics for a cold will suffer needless side effects for no benefit. Taking antibiotics unnecessarily can spur germs to mutate so that people's future infections may be untreatable. Worse, people with actual anthrax symptoms need immediate medical care, not self-treatment, anthrax experts stress.

Yet panicked Americans who haven't come close to anthrax-tainted letters circulating the East Coast are buying up Cipro. Internet sites sell Cipro packages that let people buy without seeing a doctor -- at more than $7 a pill, and some don't even contain the proper dose.

``One pediatrician called me and said, `Look, I'm going to do this; just tell me what the dose is,''' said Dr. Bernhard Wiedermann, an infectious disease specialist at Children's National Medical Center in Washington who urges doctors not to do that.

For children, the warning is especially important: animal studies suggest Cipro might damage child joints, he said, so other drugs are preferred.

Some doctors say they've agonized over those concerns yet decided to give in to patients' demands.

``We could help create strains of common drug-resistant bugs that could plague us all for years,'' acknowledge Drs. Beth Horowitz and Matthew Parker, internists practicing in downtown Washington. Yet they wrote The Washington Post this week that they're not sure the government has the situation under control and thus will continue to dispense just-in-case antibiotics.

Cipro gained fame when the FDA approved it last year as a first-line treatment against anthrax, and the government has stockpiled enough doses for 2 million people for 60 days.

Yet the generic drugs doxycycline and penicillin have long been FDA-approved anthrax treatments, and several manufacturers churn out millions of pills. What's been missing are exact dosage instructions for preventing anthrax infection in people exposed to the bacteria. Within a week, the FDA will publish those instructions, Woodcock said.

That's important in helping doctors choose antibiotics that will pose the lowest side-effect risk to each patient.

All antibiotics can cause allergic reactions. Cipro can cause central nervous system side effects such as dizziness, confusion and depression, as well as ruptures of tendons. Doxycycline's main warnings mention permanently staining children's teeth and making the skin sensitive to sunburn.

``Doxycycline is better tolerated,'' said Dr. Jeffrey Koplan, the CDC's director.

Indeed, people exposed to anthrax who show no symptoms after a few days should expect doctors to switch them from Cipro to doxycycline, Koplan said.

The CDC has mailed state health departments anthrax-preventing dosage instructions for Cipro, doxycycline and a penicillin relative called amoxicillin. The recommendations:

--For adults, 500 milligrams of Cipro twice a day for 60 days; or 100 mg of doxycycline twice a day for 60 days; or 500 mg of amoxicillin three times a day for 60 days.

--Pregnant women should take only amoxicillin.

--Doxycycline is the first choice for the elderly.

--Children need special doses based on weight.

The FDA didn't object to the CDC's recommendations but also will publish a penicillin dose.

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On the Net:

AMA anthrax information: http://www.ama-assn.org

CDC on anthrax: http://www.bt.cdc.gov/

Department of Health and Human Services on bioterrorism: http://www.hhs.gov/hottopics/healing/biological.html

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