Sandbox JA

Well-timed and effective postexposure prophylaxis can potentially save thousands of lives. PEP of asymptomatic persons should ideally start as soon as possible after exposure because its effectiveness decreases with delay in implementation. After exposure to anthrax, it is recommended 60 days of antimicrobial drug prophylaxis for immediate protection and a 3-dose series of Anthrax Vaccine Adsorbed (AVA) for long-term protection. To ensure adequate and continued protection, everyone exposed to aerosolized B. anthracis spores should receive a full 60 days of PEP antimicrobial drugs, whether they are unvaccinated, partially vaccinated, or fully vaccinated.

Antimicrobial Drugs

Ciprofloxacin, levofloxacin, and doxycycline are FDA-approved for the antimicrobial drug portion of PEP for inhalation anthrax in adults ≥18 years of age. No safety data are available for levofloxacin use beyond 30 days; thus, oral ciprofloxacin and doxycycline are recommended as first-line antimicrobial drugs for PEP. Alternative antimicrobial drugs that might be used for PEP if first-line agents are not tolerated or are unavailable include levofloxacin and moxifloxacin; amoxicillin and penicillin VK if the isolate is penicillin susceptible; and clindamycin. The antimicrobial drug linezolid cannot be used for extended periods. Also, the risk for development of resistance must be kept in mind if using β-lactam drugs.

Vaccine

Clinical trials in humans have demonstrated evidence of seroconversion after 3 doses of AVA. The vaccine should be administered subcutaneously at diagnosis and 2 and 4 weeks later (37). AVA is not FDA-approved for PEP and could be made available under an Investigational New Drug protocol or an Emergency Use Authorization in a declared emergency.