Safety of Antimicrobials for Postexposure Prophylaxis and Treatment of Anthrax: A Review

Bacillus anthracis, the causative agent for anthrax, poses a potential bioterrorism threat and is capable of causing mass morbidity and mortality. Antimicrobials are the mainstay of postexposure prophylaxis (PEP) and treatment of anthrax. We conducted this safety review of 24 select antimicrobials to identify any new or emerging serious or severe adverse events (AEs) to help inform their risk-benefit evaluation for anthrax.

Twenty-four antimicrobials were included in this review. Tertiary data sources (e.g. Lactmed, Micromedex, REPROTOX) were reviewed for safety information and summarized to evaluate the known risks of these antimicrobials. PubMed was also searched for published safety information on serious or severe AEs with these antimicrobials; AEs that met inclusion criteria were abstracted and reviewed.

A total of 1316 articles were reviewed. No consistent observations or patterns were observed among the abstracted AEs for a given antimicrobial; therefore, the literature review did not reveal evidence of new or emerging AEs that would add to the risk-benefit profiles already known from tertiary data sources.

The reviewed antimicrobials have known and/or potential serious or severe risks that may influence selection when recommending an antimicrobial for PEP or treatment of anthrax. Given the high fatality rate of anthrax, the risk-benefit evaluation favors use of these antimicrobials for anthrax. The potential risks of antimicrobials should not preclude these reviewed antimicrobials from clinical consideration for anthrax but rather guide appropriate antimicrobial selection and prioritization across different patient populations with risk mitigation measures as warranted.