ACOG: When possible, use amoxicillin for anthrax prevention in pregnant women

Nov 13, 2001 (CIDRAP News) – Pregnant and lactating women who may have been exposed to anthrax should be treated prophylactically with amoxicillin rather than ciprofloxacin when the anthrax strain is found to be penicillin-sensitive, the American College of Obstetricians and Gynecologists (ACOG) recommends.

The recommendation is based on the more established safety record for amoxicillin use during pregnancy, according to Charles M. Lockwood, MD, chair of ACOG's Committee on Obstetric Practice. The recommendation and an accompanying press release, which were issued Nov 8, also say that doxycycline should be used in pregnant women only when other antibiotics are contraindicated.

ACOG concurs with the Centers for Disease Control and Prevention (CDC) that pregnant or lactating women who may have been exposed to anthrax should be started on a 60-day course of ciprofloxacin, the organization said. "However, ACOG advises physicians to swtich such women from ciprofloxacin to amoxicillin, if and when public health officials determine that the strains of anthrax bacteria in the particular exposure are penicillin-sensitive," the press release says.

"As ob-gyns, our concern is the lack of study data on the use of ciprofloxacin in pregnant women," Lockwood said in the release. "There is no clear evidence that ciprofloxacin is teratogenic in humans, and the potential harm from anthrax exposure clearly outweighs any risks from ciprofloxacin," he added. However, "Since some studies have suggested a risk of irreversible joint disease when ciprofloxacin has been used in animals, we prefer to tread carefully here. Where possible, pregnant women should be switched to equally effective amoxicillin, since it has a more established record of general safety during pregnancy."

Doxycycline use in pregnant women should generally be avoided because it can cause problems in fetuses, including staining of teeth and impeded bone growth, the ACOG statement says. But if the patient is allergic to amoxicillin and ciprofloxacin, doxycycline should be used, "since the anthrax risks far outweigh any potential risks to the fetus from doxycycline," the release states. As an alternative, physicians and patients could consider penicillin desensitization, which takes only half an hour, officials said.

ACOG said prophylactic treatment for anthrax should be limited to women who have been exposed to confirmed environmental contamination or a high-risk source as determined by public health authorities. The initial recommended treatment is 500 mg of ciprofloxacin every 12 hours for 60 days. Once the anthrax is found to be penicillin-sensitive, treatment should be changed to 500 mg of amoxicillin three times a day for 60 days. If a woman has started taking ciprofloxacin and then finds out she is pregnant, she should continue the treatment, but she should switch to amoxicillin when the anthrax is found to be penicillin-sensitive.

Because recommendations about anthrax treatment are evolving, physicians should monitor the CDC's Web pages ( and, ACOG officials said.

See also:

ACOG press release about advisory


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