Increased US prescription trends associated with the CDC Bacillus anthracis antimicrobial postexposure prophylaxis...

We evaluated national outpatient antimicrobial prescription trends in relation to the first United States case of inhalational anthrax due to the intentional delivery of Bacillus anthracis (B. anthracis) spores.

We queried IMS HEALTH's National Prescription Audit Plus7 database for two 6-month periods (July-December) in 2001 and 2000 to describe outpatient prescription trends of antimicrobials recommended during the Centers for Disease Control and Prevention's (CDC) postexposure prophylaxis campaign.

Overall, antimicrobial utilization for the referent 6-month time frame was greater in 2000 compared to 2001. In contrast, ciprofloxacin utilization was greater in 2001 during October, the month following the index case, increasing by more than 40% over utilization in October 2000. Similarly, doxycycline utilization increased by 30% during October/November. This corresponded to relative increases in US utilization for ciprofloxacin of approximately 160,000 prescriptions for the month of October and for doxycycline of approximately 96,000 prescriptions during October and 120,000 prescriptions for November.

We conclude more widespread prescribing of ciprofloxacin and doxycycline occurred in response to the first US bioterrorist-associated anthrax attacks than was warranted based upon confirmed or suspected B. anthracis exposure alone.