What are the appropriate antibiotics for treating meningitis?

From the Guidelines

Empiric antibiotic therapy for bacterial meningitis should begin immediately with a combination of vancomycin plus a third-generation cephalosporin (ceftriaxone or cefotaxime), as recommended by the most recent guidelines 1. For adults, vancomycin is typically dosed at 15-20 mg/kg IV every 8-12 hours, while ceftriaxone is given at 2g IV every 12 hours. In children, vancomycin is dosed at 15 mg/kg IV every 6 hours, with ceftriaxone at 50-100 mg/kg/day divided every 12 hours. For patients over 50 or immunocompromised individuals, ampicillin (2g IV every 4 hours) should be added to cover Listeria monocytogenes, as suggested by the ESCMID guideline 1. Treatment duration is typically 7-14 days depending on the causative organism. Antibiotics should be started as soon as possible after obtaining blood cultures and before lumbar puncture if imaging is needed first, as delays in treatment significantly increase mortality. This combination provides broad coverage against common meningitis pathogens including Streptococcus pneumoniae (including resistant strains), Neisseria meningitidis, and Haemophilus influenzae. Once culture results and sensitivities are available, therapy should be narrowed to target the specific pathogen. Adjunctive dexamethasone (0.15 mg/kg IV every 6 hours for 2-4 days) should be considered, especially for pneumococcal meningitis, as it reduces inflammation and may improve outcomes, as recommended by the UK joint specialist societies guideline 1. It is essential to note that the use of dexamethasone in other types of meningitis, such as listeria, should be approached with caution, as it may be associated with increased mortality, as shown in a nationwide French cohort study 1.

Some key points to consider when treating bacterial meningitis include:

• The importance of prompt antibiotic treatment, as delays can significantly increase mortality 1
• The need to cover Listeria monocytogenes in patients over 50 or immunocompromised individuals, using ampicillin 1
• The use of adjunctive dexamethasone in pneumococcal meningitis, but with caution in other types of meningitis 1
• The importance of narrowing therapy to target the specific pathogen once culture results and sensitivities are available, as recommended by the UK joint specialist societies guideline 1.

Overall, the treatment of bacterial meningitis requires a prompt and targeted approach, using a combination of antibiotics and adjunctive therapies, as recommended by the most recent guidelines 1.

From the FDA Drug Label

Meropenem for injection is indicated for the treatment of bacterial meningitis caused by Haemophilus influenzae, Neisseria meningitidis and penicillin-susceptible isolates of Streptococcus pneumoniae. For pediatric patients 3 months of age and older, the meropenem for injection dose is ... 40 mg/kg every 8 hours (maximum dose is 2 grams every 8 hours), depending on the type of infection (cSSSI, cIAI, intra-abdominal infection or meningitis). For pediatric patients weighing over 50 kg administer meropenem for injection at a dose of ... 2 grams every 8 hours for meningitis.

Meropenem is an antibiotic that can be used to treat bacterial meningitis in pediatric patients 3 months of age and older, caused by specific bacteria such as Haemophilus influenzae, Neisseria meningitidis, and penicillin-susceptible isolates of Streptococcus pneumoniae. The recommended dose is 40 mg/kg every 8 hours (maximum dose is 2 grams every 8 hours) for patients weighing 50 kg or less, and 2 grams every 8 hours for patients weighing over 50 kg 2.

From the Research

Antibiotics for Meningitis

• The use of cephalosporin antibiotics, such as cefotaxime and ceftriaxone, has been shown to be effective in treating meningitis caused by various bacteria, including Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis 3.
• Third-generation cephalosporins, such as ceftriaxone and cefotaxime, have been compared to conventional antibiotics, such as ampicillin and chloramphenicol, in the treatment of acute bacterial meningitis, with no significant difference in outcomes, including risk of death, deafness, and treatment failure 4, 5.
• However, third-generation cephalosporins have been shown to have a decreased risk of culture positivity of CSF after 10-48 hours and an increased risk of diarrhea compared to conventional antibiotics 4, 5.
• Vancomycin has been recommended as part of empiric therapy for suspected bacterial meningitis, particularly in cases where resistance to penicillin and cephalosporins is a concern 6, 7.
• Meropenem has been suggested as an alternative treatment for penicillin- and cephalosporin-resistant pneumococcal meningitis, although more clinical data are needed to support its use 6.

Specific Antibiotics for Meningitis

• Cefotaxime and ceftriaxone are effective against meningitis caused by Escherichia coli, Klebsiella pneumoniae, and Proteus species, but may not be effective against Enterobacter spp. and Serratia marcescens 3.
• Ceftazidime is the only cephalosporin that yields adequate CSF concentrations to treat meningitis caused by Pseudomonas aeruginosa 3.
• Vancomycin should be included as empiric therapy for bacterial meningitis, particularly in cases where resistance to penicillin and cephalosporins is a concern 7.