Ciprofloxacin is approved for prophylaxis following inhalational anthrax exposure.
According to the Centers for Disease Control and Prevention (CDC), ciprofloxacin (500 mg, orally, two times a day for 60 days) is the antibiotic of choice for initial prophylactic therapy among asymptomatic pregnant women exposed to Bacillus anthracis.
In instances where the specific B. anthracis strain has been shown to be penicillin-sensitive, prophylactic therapy with amoxicillin (500 mg, orally, three times a day for 60 days) may be considered.
CDC guidelines for treatment of anthrax infection in pregnant women recommend either ciprofloxacin or doxycycline with one or two other antibiotics added for inhalational anthrax or systemic involvement.
While there are no controlled studies of ciprofloxacin use in pregnant women to show safety, an expert review of published data on experiences with ciprofloxacin use during pregnancy by TERIS -- the Teratogen Information System -- concluded that therapeutic doses during pregnancy are unlikely to pose a substantial teratogenic risk (quantity and quality of data = fair), but the data are insufficient to state that there is no risk. However, there are no human data available to assess the effects of long-term therapy in pregnant women such as that proposed for treatment of anthrax exposure.
Ciprofloxacin is excreted into breastmilk, but is considered as "usually compatible with breastfeeding" by the American Academy of Pediatrics.
The association between fluoroquinolones and arthropathy, although observed in immature animals and rarely reported in humans, has resulted in the restricted use of fluoroquinolones during pregnancy. Young dogs given ciprofloxacin developed arthropathy with permanent cartilage erosion in weight-bearing joints. Similar arthropathies have been reported in neonatal mice. Transient arthropathy has been reported in a small number of patients with cystic fibrosis.