chemoprophylaxis

Last reviewed 01/2018

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If an outbreak of cutaneous anthrax occurs then chemoprophylaxis should be initiated as soon as possible to give immediate protection to those at risk:

• recommended prophylaxis after exposure to B. anthracis are as follows

• adults (including pregnant women) - for 60 days
• initial (5 day) therapy - Ciprofloxacin 500mg orally every 12 hr
• further (55 day) therapy - Ciprofloxacin 500mg orally every 12 hr OR Doxycycline 100mg orally every 12 hr
• alternative therapy if strain is susceptible - Amoxicillin 500mg orally three times daily
• children - for 60 days
• initial (5 day) therapy - Ciprofloxacin 15mg/kg orally (maximum 500mg) every 12 hr (not to exceed 1g per day)
• further (55 day) therapy - Ciprofloxacin 15mg/kg orally (maximum 500mg) every 12 hr (not to exceed 1g per day) OR Doxycycline 100mg every 12hr (NB: only for children > 8yrs and >45kg:
• alternative therapy if strain is susceptible - Amoxicillin, 80mg/kg per day, in three doses (not to exceed 500mg/ dose)

In certain instances, post exposure immunisation may be indicated in addition to antimicrobial prophylaxis.

• three doses of vaccine at 0, 3 and 6 weeks after exposure should be administered (with added doses at 6 months and 1 year if there is continued exposure)
• post-exposure antibiotic prophylaxis can be reduced to 4 weeks with vaccination
• prompt post-exposure prophylaxis with antibiotics and vaccine appears to be highly effective

There is no need to provide antibiotic prophylaxis or immunisation to contacts of patients unless there is concern that they were also exposed to the initial release.

Reference:

• (1) Health Protection Agency (HPA) 2010. Anthrax: Guidelines for action in the event of a deliberate release