Doxycycline Now Favored for Anthrax Exposure

From the WebMD Archives

Oct. 31, 2001 -- Doctors have been relying on Cipro to combat the anthrax threat, but now U.S. health officials are turning to an older and cheaper antibiotic -- doxycycline.

Their decision was based on the fact that the particular anthrax strains that thousands have been exposed to -- and four have died from -- are killed by doxycycline. Federal health officials say the decision was based not on cost but on the potential threat of bacterial resistance from continued use of Cipro when it's not needed.

Cipro is used for a variety of illnesses, including serious urinary tract infections and pneumonia. With continued use of Cipro by thousands of anthrax-exposed people, we run the risk that this potent antibiotic will cease working for these other infections due to emergence of resistant bacteria. This could become a very serious public health crisis all its own.

Also, Cipro can cause a host of side effects in some people.

If doxycycline-resistant anthrax strains surface in the future, the government will then need to resort to Cipro again.

The FDA is also making sure that doctors and health officials are aware that doxycycline and penicillin are approved for treating anthrax and preventing the illness after exposure to infectious spores.

Like Cipro, doxycycline is a pill that must be taken twice a day for 60 days. The form of penicillin that is approved for treating anthrax, called "penicillin G," is a twice-daily shot -- also taken for 60 days -- and is less likely to be used after anthrax exposure. Penicillin G may be particularly useful in pregnant women and children, since it is thought to be safer for these people than either doxycycline or Cipro.

Health officials are still strongly discouraging individuals from taking any antibiotic for prevention of anthrax without the specific advice of a doctor.