The mainstay of therapy for anthrax infection is antimicrobial therapy. Antitoxin drugs should be added to combination antimicrobial therapy for any patient with suspected systemic anthrax. Uncomplicated cutaneous anthrax is treated with a single oral antimicrobial agent for a duration of 7-10 days for naturally acquired anthrax and 60 days for bioterrorism-related exposure. In cases of systemic anthrax without meningitis, the initial treatment should include ≥2 antimicrobial drugs for ≥2 weeks or until the patient is clinically stable, whichever is longer. Patients with systemic anthrax with suspected or confirmed meningitis are treated with ≥3 antimicrobial drugs for ≥2 weeks or until the patient is clinically stable, whichever is longer. Once patients with systemic illness who were exposed to aerosolized spores have completed initial combination therapy, they should be transitioned to single-agent oral treatment to prevent relapse from surviving B. anthracis spores. Supportive therapy includes hemodynamic support, mechanical ventilation, corticosteroids, procedures, and surgical intervention in certain occasions. [1]
Presence of latent spores that must be taken into account when selecting post-exposure prophylaxis or a combination of antibiotics for treatment of anthrax
1. Treatment for cutaneous anthrax, without systemic involvement[2]
Preferred regimen (1): Ciprofloxacin 500 mg PO bid for 7-10 days (regardless of penicillin susceptibility or if susceptibility is unknown)
Preferred regimen (2): Doxycycline 100 mg PO bid for 7-10 days (regardless of penicillin susceptibility or if susceptibility is unknown)
Preferred regimen (3): Levofloxacin 750 mg PO qd for 7-10 days (regardless of penicillin susceptibility or if susceptibility is unknown)
Preferred regimen (4): Moxifloxacin 400 mg PO qd for 7-10 days (regardless of penicillin susceptibility or if susceptibility is unknown)
Alternative regimen (1): Clindamycin 600 mg PO tid for 7-10 days
Alternative regimen (2): Amoxicillin 1 g PO tid (for penicillin-susceptible strains) for 7-10 days
Alternative regimen (3): Penicillin VK 500 mg PO qid (for penicillin-susceptible strains) for 7-10 days
Note: Duration of treatment is 60 days for bioterrorism-related cases and 7-10 days for naturally acquired cases.
2. Treatment for systemic anthrax including anthrax meningitis, inhalational anthrax, injectional anthrax, and gastrointestinal anthrax; and cutaneous anthrax with systemic involvement, extensive edema, or lesions of the head or neck[2]
2.1 Systemic anthrax with possible/confirmed meningitis
Treatment is with a combination of Bactericidal agent (fluoroquinolone) AND Bactericidal agent (ß-lactam) AND Protein synthesis inhibitor
2.1.1 Bactericidal agent (fluoroquinolone)
Preferred regimen (1): Ciprofloxacin 400 mg IV q8h for 2-3 weeks
Alternative regimen (1): Levofloxacin 750 mg IV q24h for 2-3 weeks
Alternative regimen (2): Moxifloxacin 400 mg IV q24h for 2-3 weeks
2.1.2 Bactericidal agent (ß-lactam) for all strains, regardless of penicillin susceptibility or if susceptibility is unknown
Preferred regimen (1): Meropenem 2 g IV q8h for 2-3 weeks
Alternative regimen (1): Imipenem 1 g IV q6h for 2-3 weeks
Alternative regimen (2): Doripenem 500 mg IV q8h for 2-3 weeks
Alternative regimen (3): Penicillin G 4 MU IV q4h (for penicillin-susceptible strains) for 2-3 weeks
Alternative regimen (4): Ampicillin 3 g IV q6h (for penicillin-susceptible strains) for 2-3 weeks
2.1.3 Protein synthesis inhibitor
Preferred regimen (1): Linezolid 600 mg IV q12h for 2-3 weeks
Alternative regimen (1): Clindamycin 900 mg IV q8h for 2-3 weeks
Alternative regimen (2): Rifampin 600 mg IV q12h for 2-3 weeks
Alternative regimen (3): Chloramphenicol 1 g IV q6-8h for 2-3 weeks
Note (1): Patients exposed to aerosolized spores will require prophylaxis to complete an antimicrobial drug course of 60 days from onset of illness.
Note (2): Increased risk for seizures associated with Imipenem/Cilastatin treatment.
Note (3): Linezolid should be used with caution in patients with thrombocytopenia because it might exacerbate it. Linezolid use for > 14 days has additional hematopoietic toxicity.
Note (4): Rifampin is not a protein synthesis inhibitor. However, it may be used in combination with other antimicrobial drugs on the basis of its in vitro synergy.
2.2 Systemic anthrax when meningitis has been excluded
2.2.1 Bactericidal agent
Preferred regimen (1): Ciprofloxacin 400 mg IV q8h for 2 weeks
Preferred regimen (2): Levofloxacin 750 mg IV q24h for 2 weeks
Preferred regimen (3): Moxifloxacin 400 mg q24h for 2 weeks
Preferred regimen (4): Meropenem 2 g IV q8h for 2 weeks
Preferred regimen (5): Imipenem 1 g IV q6h for 2 weeks
Preferred regimen (6): Doripenem 500 mg IV q8h for 2 weeks
Preferred regimen (7): Vancomycin 20 mg/kg IV q8h (maintain serum trough concentrations of 15-20 µg/mL) for 2 weeks
Preferred regimen (8): Penicillin G 4 MU IV q4h (penicillin-susceptible strains) for 2 weeks
Preferred regimen (9): Ampicillin 3 g IV q6h (penicillin-susceptible strains) for 2 weeks
2.2.2 Protein synthesis inhibitor
Preferred regimen (1): Clindamycin 900 mg IV q8h for 2 weeks
Preferred regimen (2): Linezolid 600 mg IV q12h for 2 weeks
Preferred regimen (3): Doxycycline 200 mg IV initially, then 100 mg IV q12h for 2 weeks
Preferred regimen (4): Rifampin 600 mg IV q12h for 2 weeks
Note: Patients exposed to aerosolized spores will require prophylaxis to complete an antimicrobial drug course of 60 days from onset of illness.
3. Specific considerations
3.1 Treatment of anthrax for pregnant Women
3.1.1 Intravenous antimicrobial treatment for systemic anthrax with possible/confirmed meningitis[3]
3.1.1.1 A Bactericidal Agent (Fluoroquinolone)
Preferred regimen (1): Ciprofloxacin 400 mg IV q8h for 2–3 weeks
Preferred regimen (2): Levofloxacin 750 mg IV q24h for 2–3 weeks
3.1.1.2 A Bactericidal Agent (ß-lactam)
3.1.1.2.1 For all strains, regardless of penicillin susceptibility or if susceptibility is unknown
Preferred regimen: Meropenem 2 g q8h for 2–3 weeks
3.1.1.2.2 Alternatives for penicillin-susceptible strains
Alternative regimen (1): Ampicillin 3 g IV q6h for 2–3 weeks
Alternative regimen (2): Penicillin G 4 MU IV q4h for 2–3 weeks
3.1.1.3 A Protein Synthesis Inhibitor
Preferred regimen (1): Clindamycin 900 IV mg q8h for 2–3 weeks
Preferred regimen (2): Rifampin 600 IV mg q12h for 2–3 weeks
Note: At least one antibiotic with transplacental passage is recommended.
3.1.2 Intravenous antimicrobial treatment for systemic anthrax when meningitis has been excluded
3.1.2.1 A Bactericidal Antimicrobial
Preferred regimen (1): Ciprofloxacin 400 mg IV q8h for 2 weeks
Preferred regimen (2): Levofloxacin 750 mg IV q24h for 2 weeks
3.1.2.2 A Bactericidal Agent (ß-lactam)
3.1.2.2.1 For all strains, regardless of penicillin susceptibility or if susceptibility is unknown
3.2.1 Treatment of cutaneous anthrax without systemic involvement (for children 1 month of age and older)
3.2.1.1 For all strains, regardless of penicillin susceptibility or if susceptibility is unknown
Preferred regimen (1): Ciprofloxacin 30 mg/kg/day PO bid (not to exceed 500 mg/dose) for 7-10 days
Preferred regimen (2):
If patients body weight is < 45 kg: Doxycycline 4.4 mg/kg/day PO bid (not to exceed 100 mg/dose) for 7-10 days
If patients body weight is = 45 kg: Doxycycline 100 mg/dose PO bid for 7-10 days
Preferred regimen (3): Clindamycin 30 mg/kg/day PO tid (not to exceed 600 mg/dose) for 7-10 days
Preferred regimen (4):
If patients body weight is < 50 kg: Levofloxacin 16 mg/kg/day PO bid (not to exceed 250 mg/dose) for 7-10 days
If patients body weight is > 50 kg: Levofloxacin 500 mg PO qd for 7-10 days
3.2.1.2 Alternatives for penicillin-susceptible strains
Alternative regimen (1):Amoxicillin 75 mg/kg/day PO tid (not to exceed 1 g/dose) for 7-10 days
Alternative regimen (2): Penicillin VK 50-75 mg/kg/day PO tid or qid for 7-10 days
3.2.2 Combination therapy for systemic anthrax when meningitis can be ruled out (for children 1 month of age and older)
3.2.2.1 A bactericidal antimicrobial
3.2.2.1.1 For all strains, regardless of penicillin susceptibility or if susceptibility is unknown
Preferred regimen (1): Ciprofloxacin 30 mg/kg/day IV divided q8h (not to exceed 400 mg/dose) for 14 days
Preferred regimen (2): Meropenem 60 mg/kg/day IV divided q8h (not to exceed 2 g/dose) for 14 days
Preferred regimen (3):
If patients body weight is < 50 kg: Levofloxacin 20 mg/kg/day IV divided q12h (not to exceed 250 mg/dose) for 14 days
If patients body weight is > 50 kg: Levofloxacin 500 mg IV q24h for 14 days
Preferred regimen (4): Imipenem/Cilastatin 100 mg/kg/day IV divided q6h (not to exceed 1 g/dose) for 14 days
Preferred regimen (5): Vancomycin 60 mg/kg/day IV divided q8h (follow serum concentrations) for 14 days
3.2.2.1.2 Alternatives for penicillin-susceptible strains
Alternative regimen (1): Penicillin G 400 000 U/kg/day IV divided q4h (not to exceed 4 MU/dose) for 14 days
Alternative regimen (2): Ampicillin 200 mg/kg/day IV divided q6h (not to exceed 3 g/dose) for 14 days
3.2.2.2 A Protein Synthesis Inhibitor
Preferred regimen (1): Clindamycin, 40 mg/kg/day IV divided q8h (not to exceed 900 mg/dose) for 14 days
Preferred regimen (2): (non-CNS infection dose)
If patient is < 12 y old: Linezolid 30 mg/kg/day IV divided q8h for 14 days
If patient is = 12 y old: Linezolid 30 mg/kg/day IV divided q12h (not to exceed 600 mg/dose) for 14 days
Preferred regimen (3):
If patients body weight is < 45 kg: Doxycycline 4.4 mg/kg/day IV loading dose (not to exceed 200 mg) THENDoxycycline 4.4 mg/kg/day IV divided q12h (not to exceed 100 mg/dose) for 14 days
If patients body weight is =45 kg: Doxycycline 200 mg IV loading dose THENDoxycycline 100 mg IV given q12h for 14 days
Preferred regimen (4): Rifampin 20 mg/kg/day IV divided q12h (not to exceed 300 mg/dose) for 14 days
Note: Duration of therapy for 14 days or longer until clinical criteria for stability are met. Will require prophylaxis to complete an antimicrobial course of up to 60 days from onset of illness.
3.2.3 Triple therapy for systemic anthrax (anthrax meningitis or disseminated infection and meningitis cannot be ruled out) for Children 1 Month of Age and Older
3.2.3.1 A bactericidal antimicrobial (fluoroquinolone)
Preferred regimen (1): Ciprofloxacin 30 mg/kg/day IV divided q8h (not to exceed 400 mg/dose) for 2–3 weeks
Preferred regimen (2):
If patients body weight is < 50 kg: Levofloxacin 16 mg/kg/day IV divided q12h (not to exceed 250 mg/dose) for 2–3 weeks
If patients body weight is > 50 kg: Levofloxacin 500 mg IV q24h for 2–3 weeks
Preferred regimen (3):
If patients age is 3 months to < 2 years: Moxifloxacin 12 mg/kg/day IV, divided q12h (not to exceed 200 mg/dose) for 2–3 weeks
If patients age is 2-5 years: Moxifloxacin 10 mg/kg/day IV divided q1h (not to exceed 200 mg/dose) for 2–3 weeks
If patients age is 6–11 years: Moxifloxacin 8 mg/kg/day IV divided q12h (not to exceed 200 mg/dose) for 2–3 weeks
If patients age is 12–17 years, = 45 kg body weight: Moxifloxacin 400 mg IV q24h for 2–3 weeks
If patients age is 12–17 years, < 45 kg body weight: Moxifloxacin 8 mg/kg/day IV divided q12h (not to exceed 200 mg/dose) for 2–3 weeks
3.2.3.2 A bactericidal antimicrobial (ß-lactam or glycopeptide)
3.2.3.2.1 For all strains, regardless of penicillin susceptibility testing or if susceptibility is unknown:
Preferred regimen (1): Meropenem 120 mg/kg/day IV divided q8h (not to exceed 2 g/dose) for 2–3 weeks
Preferred regimen (2): Imipenem/Cilastatin 100 mg/kg/day IV divided q6h (not to exceed 1 g/dose) for 2–3 weeks
Preferred regimen (3): Doripenem 120 mg/kg/day IV divided q8h (not to exceed 1 g/dose) for 2–3 weeks
Preferred regimen (4): Vancomycin 60 mg/kg/day IV divided q8h for 2–3 weeks
3.2.3.2.2 Alternatives for penicillin-susceptible strains
Alternative regimen (1): Penicillin G 400 000 U/kg/day IV divided q4h (not to exceed 4 MU/dose) for 2–3 weeks
Alternative regimen (2): Ampicillin 400 mg/kg/day IV divided q6h (not to exceed 3 g/dose) for 2–3 weeks
3.2.3.3 A Protein Synthesis Inhibitor
Preferred regimen (1):
If patients age is < 12 y old: Linezolid 30 mg/kg/day IV divided q8h for 2–3 weeks
If patients age is = 12 y old: Linezolid 30 mg/kg/day,IV divided q12h (not to exceed 600 mg/dose) for 2–3 weeks
Preferred regimen (2): Clindamycin 40 mg/kg/day IV divided q8h (not to exceed 900 mg/dose) for 2–3 weeks
Preferred regimen (3): Rifampin 20 mg/kg/day IV divided q12h (not to exceed 300 mg/dose) for 2–3 weeks
Preferred regimen (4): Chloramphenicol 100 mg/kg/day IV divided q6h for 2–3 weeks
Note (1): Duration of therapy for 2–3 weeks or greater, until clinical criteria for stability are met.Will require prophylaxis to complete an antimicrobial course of up to 60 days from onset of illness.
Note (2): A 400-mg dose of Ciprofloxacin IV, provides an equivalent exposure to that of a 500-mg ciprofloxacin oral tablet.
3.2.4 Oral follow-up combination therapy for severe anthrax (for Children 1 Month of Age and Older)
3.2.4.1 A bactericidal antimicrobial
3.2.4.1.1 For all strains, regardless of penicillin susceptibility or if susceptibility is unknown
Preferred regimen (1): Ciprofloxacin 30 mg/kg/day PO bid (not to exceed 500 mg/dose)
Preferred regimen (2):
If patients body weight is < 50 kg: Levofloxacin 16 mg/kg/day PO bid (not to exceed 250 mg/dose)
If patients body weight is = 50 kg: Levofloxacin 500 mg PO qd
3.2.4.1.2 Alternatives for penicillin-susceptible strains
Alternative regimen (1): Amoxicillin 75 mg/kg/day PO tid (not to exceed 1 g/dose)
Alternative regimen (2): Penicillin VK 50–75 mg/kg/day PO tid or qds
3.2.4.2 A protein synthesis inhibitor:
Preferred regimen (1):Clindamycin 30 mg/kg/day PO tid (not to exceed 600 mg/dose)
Preferred regimen (2):
If the patients body weight is < 45 kg: Doxycycline 4.4 mg/kg/day PO bid (not exceed 100 mg/dose)
If the patients body weight is = 45 kg: Doxycycline 100 mg PO bid
Preferred regimen (3): (non-CNS infection dose):
If the patients age is < 12 yrs old: Linezolid 30 mg/kg/day PO tid
If the patients age is = 12 yrs old: Linezolid 30 mg/kg/day PO bid (not to exceed 600 mg/dose)
Note: Duration of therapy to complete a treatment course of 14 days or greater. May require prophylaxis to complete an antimicrobial course of up to 60 days from onset of illness.
3.2.5 Dosing in preterm and term neonates 32 to 44 Weeks postmenstrual Age (Gestational Age Plus Chronologic Age)
3.2.5.1 Triple therapy for severe anthrax(anthrax meningitis or disseminated infection and meningitis cannot be ruled out)
Preferred regimen (1): Ciprofloxacin 20 mg/kg/day IV divided q12h for 2–3 weeks
Preferred regimen (2): Moxifloxacin 5 mg/kg/day IV q24h for 2–3 weeks
For 1–4 weeks of age
Preferred regimen (1): Ciprofloxacin 20 mg/kg/day IV divided q12h for 2–3 weeks
Preferred regimen (2): Moxifloxacin 5 mg/kg/day IV q24h for 2–3 weeks
3.2.5.1.1.2 For 34–37 week gestational age
For 0–1 week of age
Preferred regimen (1): Ciprofloxacin 20 mg/kg/day IV divided q12h for 2–3 weeks
Preferred regimen (2):Moxifloxacin 5 mg/kg/day IV q24h for 2–3 weeks
For 1–4 week of age
Preferred regimen (1): Ciprofloxacin 20 mg/kg/day IV divided q12h for 2–3 weeks
Preferred regimen (2): Moxifloxacin 5 mg/kg/day IV q24h for 2–3 weeks
3.2.5.1.1.3 Term newborn infant
For 0–1 week of age
Preferred regimen (1): Ciprofloxacin 30 mg/kg/day IV divided q12h for 2–3 weeks
Preferred regimen (2): Moxifloxacin 10 mg/kg/day IV q24h for 2–3 weeks
For 1–4 weeks of age
Preferred regimen (1): Ciprofloxacin 30 mg/kg/day IV divided q12h for 2–3 weeks
Preferred regimen (2): Moxifloxacin 10 mg/kg/day IV q24h for 2–3 weeks
3.2.5.1.2 A bactericidal antimicrobial (ß-lactam)
3.2.5.1.2.1 For all strains, regardless of penicillin susceptibility or if susceptibility is unknown:
3.2.5.1.2.1.1 For 32–34 weeks gestational age
For 0–1 week of Age :
Preferred regimen (1): Meropenem 60 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (2): Imipenem 50 mg/kg/day IV divided q12h for 2–3 weeks
Preferred regimen (3): Doripenem 20 mg/kg/day IV divided q12h for 2–3 weeks
For 1–4 week of Age :
Preferred regimen (1): Meropenem 90 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (2): Imipenem 75 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (3): Doripenem 30 mg/kg/day IV divided q8h for 2–3 weeks
3.2.5.1.2.1.2 For 34–37 week gestational age
For 0–1 week of Age :
Preferred regimen (1): Meropenem 60 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (2): Imipenem 50 mg/kg/day IV divided q12h for 2–3 weeks
Preferred regimen (3): Doripenem 20 mg/kg/day IV divided q12h for 2–3 weeks
For 1–4 week of Age :
Preferred regimen (1): Meropenem 90 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (2): Imipenem 75 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (3): Doripenem 30 mg/kg/day IV divided q8h for 2–3 weeks
3.2.5.1.2.1.3 Term newborn infant
For < 1 week of age
Preferred regimen (1): Meropenem 60 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (2): Imipenem 50 mg/kg/day IV divided q12h for 2–3 weeks
Preferred regimen (3): Doripenem 20 mg/kg/day IV divided q12h for 2–3 weeks
For 1–4 week of age
Preferred regimen (1): Meropenem 90 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (2): Imipenem 75 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (3): Doripenem 30 mg/kg/day IV divided q8h for 2–3 weeks
3.2.5.1.2.2 Alternatives for penicillin-susceptible strains
3.2.5.1.2.2.1 For 32–34 weeks gestational age
For 0–1 week of age
Alternative regimen (1): Penicillin G 200000 Units/kg/day IV divided q12h for 2–3 weeks
Alternative regimen (2): Ampicillin 100 mg/kg/day IV divided q12h for 2–3 weeks
For 1–4 week of age :
Alternative regimen (1): Penicillin G 300000 Units/kg/day IV divided q12h for 2–3 weeks
Alternative regimen (2): Ampicillin 150 mg/kg/day divided IV q12h for 2–3 weeks
3.2.5.1.2.2.2 For 34–37 week gestational age
For < 1 week of age
Alternative regimen (1): Penicillin G 300000 Units/kg/day IV divided q12h for 2–3 weeks
Alternative regimen (2): Ampicillin 150 mg/kg/day IV divided q12h for 2–3 weeks
For 1–4 week of age
Alternative regimen (1): Penicillin G 400000 Units/kg/day IV divided q12h for 2–3 weeks
Alternative regimen (2): Ampicillin 200 mg/kg/day IV divided q12h for 2–3 weeks
3.2.5.1.2.2.3 Term newborn infant
For 0–1 week of age
Alternative regimen (1): Penicillin G 300000 Units/kg/day IV divided q12h for 2–3 weeks
Alternative regimen (2): Ampicillin 150 mg/kg/day IV divided q12h for 2–3 weeks
For 1–4 week of age
Alternative regimen (1): Penicillin G 400000 Units/kg/day IV divided q12h for 2–3 weeks
Alternative regimen (2): Ampicillin 200 mg/kg/day IV divided q12h for 2–3 weeks
3.2.5.1.3 A protein synthesis inhibitor
3.2.5.1.3.1 For 32–34 weeks gestational age
For < 1 week of age
Preferred regimen (1): Linezolid 20 mg/kg/day IV divided q12h for 2–3 weeks
Preferred regimen (2): Clindamycin 10 mg/kg/day IV divided q12h for 2–3 weeks
Preferred regimen (3): Rifampin 10 mg/kg/day IV divided q12h for 2–3 weeks
Preferred regimen (4): Chloramphenicol 25 mg/kg/day IV q24h for 2–3 weeks
For 1–4 week of age
Preferred regimen (1): Linezolid 30 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (2): Clindamycin 15 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (3): Rifampin 10 mg/kg/day IV divided q12h for 2–3 weeks
Preferred regimen (4): Chloramphenicol 50 mg/kg/day IV q12h for 2–3 weeks
3.2.5.1.3.2 For 34–37 week gestational age
For < 1 week of age
Preferred regimen (1): Linezolid 30 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (2): Clindamycin 15 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (3): Rifampin 10 mg/kg/day IV divided q12h for 2–3 weeks
Preferred regimen (4): Chloramphenicol 25 mg/kg/day IV q24h for 2–3 weeks
For 1–4 week of age
Preferred regimen (1): Linezolid 30 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (2): Clindamycin 20 mg/kg/day IV divided q6h for 2–3 weeks
Preferred regimen (3): Rifampin 10 mg/kg/day IV divided q12h for 2–3 weeks
Preferred regimen (4): Chloramphenicol 50 mg/kg/day IV q12h for 2–3 weeks
3.2.5.1.3.3 Term newborn infant
For < 1 week of age
Preferred regimen (1): Linezolid 30 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (2): Clindamycin 15 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (3): Rifampin 10 mg/kg/day IV divided q12h for 2–3 week
Preferred regimen (4): Chloramphenicol 25 mg/kg/day IV q24h for 2–3 weeks
For 1–4 week of age
Preferred regimen (1): Linezolid 30 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (2): Clindamycin 20 mg/kg/day IV divided q6h for 2–3 weeks
Preferred regimen (3): Rifampin 20 mg/kg/day IV divided q12h for 2–3 weeks
Preferred regimen (4): Chloramphenicol 50 mg/kg/day IV q12h for 2–3 weeks
Note :Duration of therapy for 2–3 weeks, until clinical criteria for stability are met. Will require prophylaxis to complete an antibiotic course of upto 60 days from onset of illness.
3.2.5.2 Therapy for severe anthrax when meningitis can be ruled out
3.2.5.2.1 A bactericidal antimicrobial
3.2.5.2.1.1 For all strains, regardless of penicillin susceptibility or if susceptibility is unknown
3.2.5.2.1.1.1 For 32–34 weeks gestational age
For < 1 week of age
Preferred regimen (1): Ciprofloxacin 20 mg/kg/day IV divided q12h for 2-3 weeks
Preferred regimen (2): Meropenem 40 mg/kg/day IV divided q8h for 2-3 weeks
Preferred regimen (3): Imipenem 40 mg/kg/day IV divided q12h for 2-3 weeks
For 1–4 week of age
Preferred regimen (1): Ciprofloxacin 20 mg/kg/day IV divided q12h for 2-3 weeks
Preferred regimen (2): Meropenem 60 mg/kg/day IV divided q8h for 2-3 weeks
Preferred regimen (3): Imipenem 50 mg/kg/day IV divided q12h for 2-3 weeks
3.2.5.2.1.1.2 For 34–37 week gestational age
For < 1 week of age
Preferred regimen (1): Ciprofloxacin 20 mg/kg/day IV divided q12h for 2-3 weeks
Preferred regimen (2): Meropenem 60 mg/kg/day IV divided q8h for 2-3 weeks
Preferred regimen (3): Imipenem 50 mg/kg/day IV divided q12h for 2-3 weeks
For 1–4 week of age
Preferred regimen (1): Ciprofloxacin 20 mg/kg/day IV divided q12h for 2-3 weeks
Preferred regimen (2): Meropenem 60 mg/kg/day IV divided q8h for 2-3 weeks
Preferred regimen (3): Imipenem 75 mg/kg/day IV divided q8h for 2-3 weeks
3.2.5.2.1.1.3 Term Newborn Infant
For < 1 week of age
Preferred regimen (1): Ciprofloxacin 30 mg/kg/day IV divided q12h for 2-3 weeks
Preferred regimen (2): Meropenem 60 mg/kg/day IV divided q8h for 2-3 weeks
Preferred regimen (3): Imipenem 50 mg/kg/day IV divided q12h for 2-3 weeks
For 1–4 week of age
Preferred regimen (1): Ciprofloxacin 30 mg/kg/day IV divided q12h for 2-3 weeks
Preferred regimen (2): Meropenem 60 mg/kg/day IV divided q8h for 2-3 weeks
Preferred regimen (3): Imipenem 75 mg/kg/day IV divided q8h for 2-3 weeks
Vancomycin IV (dosing based on serum creatinine for infants of 32 weeks gestational age). Follow vancomycin serum concentrations to modify dose.
If Serum creatinine < 0.7 then Vancomycin 15 mg/kg/dose IV q12h for 2-3 weeks
If Serum creatinine 0.7 -0.9 then Vancomycin 20 mg/kg/dose IV q24h for 2-3 weeks
If Serum creatinine 1–1.2 then Vancomycin 15 mg/kg/dose IV q24h for 2-3 weeks
If Serum creatinine 1.3–1.6 then Vancomycin 10 mg/kg/dose IV q24h for 2-3 weeks
If Serum creatinine > 1.6 then Vancomycin mg/kg/dose IV q48h for 2-3 weeks
Note: Begin treatment with a 20 mg/kg loading dose OR
3.2.5.2.1.2 Alternatives for penicillin-susceptible strains
3.2.5.2.1.2.1 For 32–34 weeks gestational age
For < 1 week of age
Alternative regimen (1): Penicillin G 200000 U/kg/day IV divided q12h for 2-3 weeks
Alternative regimen (2): Ampicillin 100 mg/kg/day IV divided q12h for 2-3 weeks
For 1–4 week of age
Alternative regimen (1): Penicillin G 300000 U/kg/day IV divided q8h for 2-3 weeks
Alternative regimen (2): Ampicillin 150 mg/kg/day IV divided q8h for 2-3 weeks
3.2.5.2.1.2.2 For 34–37 week gestational age
For < 1 week of age
Alternative regimen (1): Penicillin G 300000 U/kg/day IV divided q8h for 2-3 weeks
Alternative regimen (2): Ampicillin 150 mg/kg/day IV divided q8h for 2-3 weeks
For 1–4 week of age
Alternative regimen (1): Penicillin G 400000 U/kg/day IV divided q6h for 2-3 weeks
Alternative regimen (2): Ampicillin 200 mg/kg/day IV divided q6h for 2-3 weeks
3.2.5.2.1.2.3 Term newborn infant
For < 1 week of age
Alternative regimen (1): Penicillin G 300000 U/kg/day IV divided q8h for 2-3 weeks
Alternative regimen (2): Ampicillin 150 mg/kg/day IV divided q8h for 2-3 weeks
For 1–4 week of age
Alternative regimen (1): Penicillin G 400000 U/kg/day IV divided q6h for 2-3 weeks
Alternative regimen (2):Ampicillin 200 mg/kg/day IV divided q6h for 2-3 weeks
3.2.5.2.2 A protein synthesis inhibitor
3.2.5.2.2.1 For 32–34 weeks gestational age
For < 1 week of age
Preferred regimen (1): Clindamycin 10 mg/kg/day IV divided q12h for 2–3 weeks
Preferred regimen (2): Linezolid 20 mg/kg/day IV divided q12h for 2–3 weeks
Preferred regimen (3): Rifampin 10 mg/kg/day IV q24h for 2–3 weeks
For 1–4 week of age
Preferred regimen (1): Clindamycin 15 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (2): Linezolid 30 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (3): Rifampin 10 mg/kg/day IV q24h for 2–3 weeks
3.2.5.2.2.2 For 34–37 week gestational age
For < 1 week of age
Preferred regimen (1): Clindamycin 15 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (2): Linezolid 30 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (3): Rifampin 10 mg/kg/day IV q24h for 2–3 weeks
For 1–4 week of age
Preferred regimen (1): Clindamycin 20 mg/kg/day IV divided q6h for 2–3 weeks
Preferred regimen (2): Linezolid 30 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (3): Rifampin 10 mg/kg/day IV q24h for 2–3 weeks
3.2.5.2.2.3 Term newborn infant
For 0–1 week of age :
Preferred regimen (1): Clindamycin 15 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (2): Linezolid 30 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (3): Doxycycline 4.4 mg/kg/day IV divided q12h, (loading dose 4.4 mg/kg) for 2–3 weeks
Preferred regimen (4): Rifampin 10 mg/kg/day IV q24h for 2–3 weeks
For 1–4 week of age :
Preferred regimen (1): Clindamycin 20 mg/kg/day IV divided q6h for 2–3 weeks
Preferred regimen (2): Linezolid 30 mg/kg/day IV divided q8h for 2–3 weeks
Preferred regimen (3): Doxycycline 4.4 mg/kg/day IV divided q12h, (loading dose 4.4 mg/kg) for 2–3 weeks
Preferred regimen (4): Rifampin 10 mg/kg/day IV q24h for 2–3 weeks
Note: Duration of therapy for 2–3 weeks, until clinical criteria for stability are met (see text). Will require prophylaxis to complete an antimicrobial course of upto 60 days from onset of illness
3.2.5.3 Oral follow-up combination therapy for severe anthrax
3.2.5.3.1 A bactericidal antimicrobial
3.2.5.3.1.1 For all strains, regardless of penicillin susceptibility or if susceptibility is unknown
3.2.5.3.1.1.1 For 32–34 weeks gestational age
For < 1 week of age
Preferred regimen: Ciprofloxacin 20 mg/kg/day PO bid
For 1–4 week of age
Preferred regimen: Ciprofloxacin 20 mg/kg/day PO bid
3.2.5.3.1.1.2 For 34–37 week gestational age
For < 1 week of age
Preferred regimen: Ciprofloxacin 20 mg/kg/day PO bid
For 1–4 week of age
Preferred regimen: Ciprofloxacin 20 mg/kg/day PO bid
3.2.5.3.1.1.3 Term newborn infant
For < 1 week of age
Preferred regimen: Ciprofloxacin 30 mg/kg/day PO bid
For 1–4 week of age
Preferred regimen: Ciprofloxacin 30 mg/kg/day PO bid OR
3.2.5.3.1.2 Alternatives for penicillin-susceptible strains
3.2.5.3.1.2.1 For 32–34 weeks gestational age
For < 1 week of age
Alternative regimen (1): Amoxicillin 50 mg/kg/day PO bid
Alternative regimen (2): Penicillin VK 50 mg/kg/day PO bid
For 1–4 week of age
Alternative regimen (1): Amoxicillin 75 mg/kg/day PO bid
Alternative regimen (2): Penicillin VK 75 mg/kg/day PO bid
3.2.5.3.1.2.2 For 34–37 week gestational age
For < 1 week of age
Alternative regimen (1): Amoxicillin 50 mg/kg/day PO bid
Alternative regimen (2): Penicillin VK 50 mg/kg/day PO bid
For 1–4 week of age
Alternative regimen (1): Amoxicillin 75 mg/kg/day PO bid
Alternative regimen (2): Penicillin VK 75 mg/kg/day PO tid
3.2.5.3.1.2.3 Term newborn infant
For < 1 week of age
Alternative regimen (1): Amoxicillin 75 mg/kg/day PO tid
Alternative regimen (2): Penicillin VK 75 mg/kg/day PO tid
For 1–4 week of age
Alternative regimen (1): Amoxicillin 75 mg/kg/day PO tid
Alternative regimen (2): Penicillin VK 75 mg/kg/day PO tid or qid
3.2.5.3.2 A protein synthesis inhibitor
3.2.5.3.2.1 For 32–34 weeks gestational age
For < 1 week of age
Preferred regimen (1): Clindamycin 10 mg/kg/day PO bid
Preferred regimen (2): Linezolid 20 mg/kg/day PO bid
For 1–4 week of age
Preferred regimen (1): Clindamycin 15 mg/kg/day PO bid
Preferred regimen (2): Linezolid 30 mg/kg/day PO bid
3.2.5.3.2.2 For 34–37 week gestational age
For < 1 week of age
Preferred regimen (1): Clindamycin 15 mg/kg/day PO tid
Preferred regimen (2): Linezolid 30 mg/kg/day PO tid
For 1–4 week of age
Preferred regimen (1): Clindamycin 20 mg/kg/day PO qid
Preferred regimen (2): Linezolid 30 mg/kg/day PO tid
3.2.5.3.2.3 Term newborn infant
For < 1 week of age
Preferred regimen (1): Clindamycin 15 mg/kg/day PO tid
Preferred regimen (3): Linezolid 30 mg/kg/day PO tid
Note: Duration of therapy to complete a treatment course of 10–14 days or greater. May require prophylaxis to complete an antimicrobial course of upto 60 days from onset of illness.
3.2.5.4 Treatment of cutaneous anthrax without systemic involvement
3.2.5.4.1 For all strains, regardless of penicillin susceptibility or if susceptibility is unknown
3.2.5.4.1.1 For 32–34 weeks gestational age
For < 1 week of age
Preferred regimen (1): Ciprofloxacin 20 mg/kg/day PO bid
Preferred regimen (2): Clindamycin 10 mg/kg/day PO bid
For 1–4 week of age
Preferred regimen (1): Ciprofloxacin 20 mg/kg/day PO bid
Preferred regimen (2): Clindamycin 15 mg/kg/day PO tid
3.2.5.4.1.2 For 34–37 week gestational age
For < 1 week of age
Preferred regimen (1): Ciprofloxacin 20 mg/kg/day PO bid
Preferred regimen (2): Clindamycin 15 mg/kg/day PO tid
For 1–4 week of age
Preferred regimen (1): Ciprofloxacin 20 mg/kg/day PO bid
Preferred regimen (2): Clindamycin 20 mg/kg/day PO qid
3.2.5.4.1.3 'Term newborn infant
For < 1 week of age
Preferred regimen (1): Ciprofloxacin 30 mg/kg/day PO bid
Preferred regimen (3): Clindamycin 20 mg/kg/day PO qid
3.2.5.4.2 Alternatives for penicillin-susceptible strains
3.2.5.4.2.1 For 32–34 weeks gestational age
For < 1 week of age
Alternative regimen (1): Amoxicillin 50 mg/kg/day PO bid
Alternative regimen (2): Penicillin Vk 50 mg/kg/day PO bid
For 1–4 week of age
Alternative regimen (1): Amoxicillin 75 mg/kg/day PO tid
Alternative regimen (2): Penicillin Vk 75 mg/kg/day PO tid
3.2.5.4.2.2 For 34–37 week gestational age
For < 1 week of age
Alternative regimen (1): Amoxicillin 50 mg/kg/day PO bid
Alternative regimen (2): Penicillin Vk 50 mg/kg/day PO bid
For 1–4 week of age
Alternative regimen (1): Amoxicillin 75 mg/kg/day PO bid
Alternative regimen (2): Penicillin Vk 75 mg/kg/day PO bid
3.2.5.4.2.3 Term newborn infant
For < 1 week of age
Alternative regimen (1): Amoxicillin 75 mg/kg/day PO tid
Alternative regimen (2): Penicillin Vk 75 mg/kg/day PO tid
For 1–4 week of age
Alternative regimen (1): Amoxicillin 75 mg/kg/day PO tid
Alternative regimen (2): Penicillin Vk 75 mg/kg/day PO tid or qid
Note : Duration of therapy for naturally acquired infection is 7–10 days and for a biological weapon–related event,may require additional prophylaxis for inhaled spores to complete an antimicrobial course of up to 60 days from onset of illness.
An antitoxin should be added to combination antibiotic treatment for any patient for whom there is a high level of clinical suspicion for systemic anthrax. Given that systemic anthrax has a high case-fatality rate and the risk for antitoxin treatment appears to be low, the potential benefit achieved by adding antitoxin to combination antibiotic treatment outweighs the potential risk.
Raxibacumab is a recombinant, fully humanized, IgG1λ monoclonal antibody. It appeared safe and well tolerated in 333 healthy adults who received the recommended dose of 40 mg/kg.
Most adverse events were transient and mild to moderate in severity. Pruritis was noted in 2.1% of persons treated with raxibacumab and in none treated with placebo. Although raxibacumab has not been given to patients with systemic anthrax, it is FDA-approved for postexposure prophylaxis.[1]
AIGIV is a human polyclonal antiserum made from plasma of persons immunized with Anthrax Vaccine Absorbed (AVA), which might have some direct effect on Lethal Factor (LF) and Edema Factor (EF). It was evaluated in 74 healthy adult volunteers and appears safe and well tolerated at all doses tested.
AIGIV is not FDA approved and could be made available under an Investigational New Drug protocol or an Emergency Use Authorization during a declared emergency.[1]
Many patients with cutaneous anthrax can be treated as outpatients.
Patients with symptoms or signs of systemic involvement (e.g., tachycardia, tachypnea, hypotension, hyperthermia, hypothermia, leukocytosis) or with lesions that involve the head, neck, or upper torso or that are large, bullous, multiple, or surrounded by edema, have higher mortality rates. Hospitalization is warranted for all patients with systemic cutaneous anthrax; gastrointestinal, injection, or inhalation anthrax; or anthrax meningitis or bacteremia.
Failure to fulfill systemic inflammatory response syndrome criteria should not decrease concern for sepsis because patients with systemic anthrax might not initially appear critically ill. Inhalation anthrax can have a prodromal phase followed by a fulminant phase. Patients with systemic anthrax have had debilitating symptoms, followed first by transitory improvement and then by precipitous hemodynamic deterioration. Because of this potential for sudden decompensation, hospitalized patients should have careful hemodynamic monitoring, including continuous pulse oximetry and telemetry.