TABLE 7. Empiric* treatment regimens for nonpregnant adults aged ≥18 years with cutaneous anthrax without signs and symptoms of meningitis, by descending order of preference — CDC recommendations, 2023.

Treatment (listed drugs joined by “or” are considered equivalent)	Dosage
First-line antimicrobial drug
Doxycycline†,§	100 mg every 12 hours orally
or
Minocycline†	200 mg x 1 dose orally, then 100 mg every 12 hours orally
or
Ciprofloxacin†	500 mg every 12 hours orally
or
Levofloxacin†	750 mg every 24 hours orally
PCN-S only:
Amoxicillin¶,**	1 g every 8 hours orally
or
Penicillin VK¶	500 mg every 6 hours orally
Alternative antimicrobial drug††
Amoxicillin/clavulanate¶	1:16 formulation (1 g/62.5 mg) in 2 tablets every 12 hours orally
or
Amoxicillin/clavulanate¶	1:7 formulation (875/125 mg) every 12 hours orally
Moxifloxacin§,¶	400 mg every 24 hours orally
Clindamycin¶	600 mg every 8 hours orally
Ofloxacin¶	400 mg every 12 hours orally
Omadacycline¶	450 mg every 24 hours orally x 2 days, then 300 mg every 24 hours orally
Linezolid¶	600 mg every 12 hours orally
Tetracycline†	500 mg every 6 hours orally
Clarithromycin¶,§§	500 mg every 12 hours orally (only initiate after at least 3 days of treatment with any of the other antimicrobials listed)
Dalbavancin¶	1 g x 1 dose IV, then 500 mg weekly IV
Imipenem/cilastatin¶	1 g every 6 hours IV
or
Meropenem¶	2 g every 8 hours IV
Vancomycin¶	15 mg/kg every 12 hours IV over a period of 1–2 hours (target AUC24 of 400–600 µg x h/mL [preferred]; if AUC24 is not available, maintain serum trough concentrations of 15–20 µg/mL)
Antitoxin (only to be used if antimicrobial drugs are not available or not appropriate; listed antitoxins joined by “or” are considered equivalent)
Raxibacumab¶¶	40 mg/kg in a single dose IV
or
Obiltoxaximab¶¶	16 mg/kg in a single dose IV
AIGIV***	420 units IV

Abbreviation: AIGIV = anthrax immunoglobulin intravenous; FDA = Food and Drug Administration; IV = intravenous; PCN-S = penicillin-susceptible strains; PEPAbx = antimicrobial postexposure prophylaxis for anthrax.

* Definitive therapy should be directed by antibiotic susceptibility test results, when available.

^† Approved by FDA for anthrax PEPAbx, treatment, or both, but specific uses (e.g., doses, dosing schedules, and patient populations) recommended in this report might differ from the FDA-approved labeling.

^§ If liquid formulations are not available for adults who cannot swallow pills, instructions are available for preparing oral suspensions of moxifloxacin (Source: Hutchinson DJ, Johnson CE, Klein KC. Stability of extemporaneously prepared moxifloxacin oral suspensions. Am J Health Syst Pharm 2009;66:665–7.121) and doxycycline (Source: CDC. In an anthrax emergency: how to prepare doxycycline hyclate for children and adults who cannot swallow pills. Atlanta, GA: US Department of Health and Human Services, CDC; 2020. https://www.cdc.gov/anthrax/public-health/doxy-crushing-instruction-pamphlet.html).

^¶ Not approved by FDA for anthrax PEPAbx or treatment.

** Ampicillin 500 mg every 6 hours can be used as an alternative to amoxicillin, if available.

^†† Alternative selections are for patients who have contraindications to or cannot tolerate first-line antimicrobial drugs or if first-line antimicrobial drugs are not available.

^§§ Clarithromycin is unlikely to be effective if the patient has bacteremia, thus a different antimicrobial drug must be used initially to clear bacteremia.

^¶¶ Premedicate with IV or oral diphenhydramine within 1 hour before administration. Hypersensitivity and anaphylaxis have been reported after raxibacumab and obiltoxaximab administration.

*** An 840-unit dose of AIGIV can be considered for severe cases.