Specific Organisms and Therapeutic Regimens

Organism-specific therapeutic regimens for bacterial meningitis are outlined below, including those for Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Listeria monocytogenes, Streptococcus agalactiae, Enterobacteriaceae organisms, and Pseudomonas aeruginosa.^{[1, 2, 3, 4]}

Streptococcus pneumoniae meningitis

Table 1. Primary and alternative antimicrobial agents for Streptococcus pneumoniae meningitis. (Open Table in a new window)

Susceptibility	Primary Therapy	Alternative Therapy
Penicillin MIC ≤0.06 mcg/mL	Penicillin or ampicillin	Ceftriaxone or cefotaxime
Penicillin MIC ≥0.12 mcg/mL	Penicillin or ampicillin	Ceftriaxone or cefotaxime
Ceftriaxone or cefotaxime MIC < 1 mcg/mL	Ceftriaxone or cefotaxime	Cefepime, meropenem
Ceftriaxone or cefotaxime MIC ≥1 mcg/mL	Vancomycin plus a ceftriaxone or cefotaxime	Fluoroquinolone

Table 2. Dosages of antimicrobial therapy for S pneumoniae meningitis. (Open Table in a new window)

Antimicrobial Agent	Adults: Total Daily Dose (Dose Interval in Hours)	Pediatrics: Total Daily Dose (Dose Interval in Hours)
Ampicillin	12 g (4)	300-400 mg/kg (6)
Cefepime	6 g (8)	150 mg/kg (8)
Cefotaxime	8-12 g (4-6)	300 mg/kg (6-8)
Ceftriaxone	4 g (12)	100 mg/kg (12-24)
Fluoroquinolone	Varies by specific drug	Varies by specific drug
Meropenem	6 g (8)	120 mg/kg (8)
Penicillin G	24 million units (4)	300,000 units/kg (4-6)
Vancomycin	30-60 mg/kg (8-12)	60 mg/kg (6)

Haemophilus influenzae meningitis

Table 3. Primary and alternative antimicrobial agents for Haemophilus influenzae meningitis. (Open Table in a new window)

Susceptibility	Primary Therapy	Alternative Therapy
Beta-lactamase-negative	Ampicillin	Ceftriaxone or cefotaxime, cefepime, fluoroquinolone, aztreonam
Beta-lactamase-positive	Ceftriaxone or cefotaxime	Cefepime, fluoroquinolone, aztreonam

Table 4. Dosages of antimicrobial therapy for H influenzae meningitis. (Open Table in a new window)

Antimicrobial Agent	Adults: Total Daily Dose (Dose Interval in Hours)	Pediatrics: Total Daily Dose (Dose Interval in Hours)
Ampicillin	12 g (4)	300-400 mg/kg (6)
Aztreonam	6-8 g (6-8)	120 mg/kg (6-8)
Cefepime	6 g (8)	150 mg/kg (8)
Cefotaxime	8-12 g (4-6)	300 mg/kg (6-8)
Ceftriaxone	4 g (12)	100 mg/kg (12-24)
Fluoroquinolone	Varies by specific drug	Varies by specific drug

Neisseria meningitidis meningitis

Table 5. Primary and alternative antimicrobial agents for Neisseria meningitidis meningitis. (Open Table in a new window)

Susceptibility	Primary Therapy	Alternative Therapy
Penicillin MIC < 0.1 mcg/mL	Penicillin G or ampicillin	Ceftriaxone or cefotaxime
Penicillin MIC 0.1 to 1.0 mcg/mL	Ceftriaxone or cefotaxime	Fluoroquinolone, meropenem

Table 6. Dosages of antimicrobial therapy for N meningitidis meningitis. (Open Table in a new window)

Antimicrobial Agent	Adults: Total Daily Dose (Dose Interval in Hours)	Pediatrics: Total Daily Dose (Dose Interval in Hours)
Ampicillin	12 g (4)	300-400 mg/kg (6)
Cefotaxime	8-12 g (4-6)	300 mg/kg (6-8)
Ceftriaxone	4 g (12)	100 mg/kg (12-24)
Fluoroquinolone	Varies by specific drug	Varies by specific drug
Meropenem	6 g (8)	120 mg/kg (8)
Penicillin G	24 million units (4)	300000 units/kg (4-6)

Listeria monocytogenes meningitis

Table 7. Dosages of antimicrobial therapy for Listeria monocytogenes meningitis. (Open Table in a new window)

Primary Therapy	Alternative Therapy
Ampicillin or penicillin G	Trimethoprim-sulfamethoxazole

Table 8. Dosages of antimicrobial therapy for L monocytogenes meningitis. (Open Table in a new window)

Antimicrobial Agent	Adults: Total Daily Dose (Dose Interval in Hours)	Pediatrics: Total Daily Dose (Dose Interval in Hours)
Ampicillin	12 g (4)	300-400 mg/kg (6)
Penicillin G	24 million units (4)	300000 units/kg (4-6)
Trimethoprim-sulfamethoxazole	10-20 mg/kg (6-12)	10-20 mg/kg (6-12)

Streptococcus agalactiae meningitis

Table 9. Dosages of antimicrobial therapy for Streptococcus agalactiae meningitis. (Open Table in a new window)

Primary Therapy	Alternative Therapy
Ampicillin or penicillin G	Ceftriaxone or cefotaxime

Table 10. Dosages of antimicrobial therapy for S agalactiae meningitis. (Open Table in a new window)

Antimicrobial Agent	Adults: Total Daily Dose (Dose Interval in Hours)	Pediatrics: Total Daily Dose (Dose Interval in Hours)
Ampicillin	12 g (4)	300-400 mg/kg (6)
Cefotaxime	8-12 g (4-6)	300 mg/kg (6-8)
Ceftriaxone	4 g (12)	100 mg/kg (12-24)
Penicillin G	24 million units (4)	300000 units/kg (4-6)

Enterobacteriaceae organisms

Table 11. Dosages of antimicrobial therapy for Enterobacteriaceae organisms. (Open Table in a new window)

Primary Therapy	Alternative Therapy
Ceftriaxone or cefotaxime	Aztreonam, fluoroquinolone, meropenem, trimethoprim-sulfamethoxazole, ampicillin

Table 12. Dosages of antimicrobial therapy for Enterobacteriaceae organisms. (Open Table in a new window)

Antimicrobial Agent	Adults: Total Daily Dose (Dose Interval in Hours)	Pediatrics: Total Daily Dose (Dose Interval in Hours)
Ampicillin	12 g (4)	300-400 mg/kg (6)
Aztreonam	6-8 g (6-8)	120 mg/kg (6-8)
Cefotaxime	8-12 g (4-6)	300 mg/kg (6-8)
Ceftriaxone	4 g (12)	100 mg/kg (12-24)
Fluoroquinolone	Varies by specific drug	Varies by specific drug
Meropenem	6 g (8)	120 mg/kg (8)
Trimethoprim-sulfamethoxazole	10-20 mg/kg (6-12)	10-20 mg/kg (6-12)

Pseudomonas aeruginosa meningitis

Table 13. Dosages of antimicrobial therapy for Pseudomonas aeruginosa meningitis. (Open Table in a new window)

Primary Therapy	Alternative Therapy
Cefepime or ceftazidime	Aztreonam, ciprofloxacin, meropenem

Table 14. Dosages of antimicrobial therapy for P aeruginosa meningitis. (Open Table in a new window)

Antimicrobial Agent	Adults: Total Daily Dose (Dose Interval in Hours)	Pediatrics: Total Daily Dose (Dose Interval in Hours)
Aztreonam	6-8 g (6-8)	120 mg/kg (6-8)
Cefepime	6 g (8)	150 mg/kg (8)
Ceftazidime	6 g (8)	200 mg/kg (8)
Ciprofloxacin	800-1200 mg (8-12)	30 mg/kg (8-12)
Meropenem	6 g (8)	120 mg/kg (8)

Master list of dosages by antimicrobial agent for adult and pediatric bacterial meningitis

Table 15. Master list of dosages by antimicrobial agent for adult and pediatric bacterial meningitis. (Open Table in a new window)

Antimicrobial Agent	Adults: Total Daily Dose (Dose Interval in Hours)	Pediatrics: Total Daily Dose (Dose Interval in Hours)
Amikacin	15 mg/kg (8)	22.5 mg/kg (8)
Ampicillin	12 g (4)	300-400 mg/kg (6)
Aztreonam	6-8 g (6-8)	120 mg/kg (6-8)
Cefepime	6 g (8)	150 mg/kg (8)
Cefotaxime	8-12 g (4-6)	300 mg/kg (6-8)
Ceftazidime	6 g (8)	200 mg/kg (8)
Ceftriaxone	4 g (12)	100 mg/kg (12-24)
Ciprofloxacin	800-1200 mg (8-12)	30 mg/kg (8-12)
Gentamicin	5 mg/kg (8)	7.5 mg/kg (8)
Meropenem	6 g (8)	120 mg/kg (8)
Moxifloxacin	400 mg (24)	Dose not established
Nafcillin	12 g (4)	200 mg/kg (6)
Penicillin G potassium	24 million units (4)	300,000 units/kg (4-6)
Rifampin	600 mg (24)	20 mg/kg (24)
Tobramycin	5 mg/kg (8)	7.5 mg/kg (8)
Trimethoprim-sulfamethoxazole (cotrimoxazole)	10-20 mg/kg (6-12)	10-20 mg/kg (6-12)
Vancomycin	30-60 mg/kg (8-12)	60 mg/kg (6)