What is the recommended treatment for suspected bacterial meningitis?

From the Guidelines

Suspected bacterial meningitis requires immediate empiric antibiotic therapy, ideally after blood cultures and lumbar puncture are obtained, but without delay if these procedures would postpone treatment, with the recommended empiric regimen including a combination of vancomycin and a third-generation cephalosporin, and dexamethasone administered before or with the first dose of antibiotics to reduce inflammatory complications. The recommended empiric regimen for adults includes a combination of vancomycin (15-20 mg/kg IV every 8-12 hours) plus a third-generation cephalosporin such as ceftriaxone (2g IV every 12 hours) or cefotaxime (2g IV every 4-6 hours) 1. For patients over 50 or those with compromised immunity, ampicillin (2g IV every 4 hours) should be added to cover Listeria monocytogenes 1. Dexamethasone (10 mg IV every 6 hours) should be administered before or with the first dose of antibiotics to reduce inflammatory complications, particularly in pneumococcal meningitis, and continued for 4 days if pneumococcal meningitis is confirmed or thought probable 1. Once the causative organism is identified through cultures, therapy can be narrowed. Treatment typically continues for 7-14 days depending on the pathogen. Rapid initiation of appropriate antibiotics is critical as bacterial meningitis can progress quickly, with mortality increasing significantly when treatment is delayed. The blood-brain barrier requires high-dose parenteral antibiotics to achieve adequate concentrations in the cerebrospinal fluid where the infection is located. Some key considerations in the management of suspected bacterial meningitis include:

• Stabilization of the patient’s airway, breathing, and circulation as an immediate priority 1
• Documentation of the patient’s conscious level using the Glasgow coma scale 1
• Blood cultures should be taken as soon as possible and within 1 hour of arrival at hospital 1
• Lumbar puncture should be performed within 1 hour of arrival at hospital, provided it is safe to do so, and treatment commenced immediately after the lumbar puncture has been performed 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.

The recommended treatment for suspected bacterial meningitis is meropenem for injection at a dose of:

• 40 mg/kg every 8 hours (maximum dose is 2 grams every 8 hours) for pediatric patients 3 months of age and older, or
• 2 grams every 8 hours for pediatric patients weighing over 50 kg 2.

From the Research

Recommended Treatment for Suspected Bacterial Meningitis

The recommended treatment for suspected bacterial meningitis involves the use of antibiotics, with the specific regimen depending on various factors such as the suspected causative organism and its antimicrobial susceptibility pattern.

• For patients with suspected pneumococcal meningitis, the combination of vancomycin and a third-generation cephalosporin (either cefotaxime or ceftriaxone) is recommended as empiric therapy, pending isolation of the organism and in vitro susceptibility testing 3.
• In cases where the pneumococcal isolate is highly resistant to penicillin or cephalosporins, the addition of rifampin can be considered if the organism is susceptible in vitro, the expected clinical or bacteriologic response is delayed, or the pneumococcal isolate has a cefotaxime or ceftriaxone minimal inhibitory concentration greater than 4 μg/mL 3.
• Meropenem is not recommended as monotherapy for highly penicillin- or cephalosporin-resistant strains, but the use of a fluoroquinolone with in vitro activity against Streptococcus pneumoniae (specifically moxifloxacin) is an option in patients failing standard therapy, and should be combined with a third-generation cephalosporin or vancomycin 3.
• The therapeutic efficacy of meropenem in combination with vancomycin has been evaluated in a rabbit model of meningitis caused by penicillin-resistant Streptococcus pneumoniae, and was found to be comparable to that of ceftriaxone and vancomycin 4.
• Ceftriaxone has been shown to be safe and effective for the treatment of bacterial meningitis when administered once daily, with CSF concentrations remaining above the MIC of the pathogenic bacteria for an extended period 5.
• The combination of vancomycin and ceftriaxone has been found to be synergistic against pneumococcal strains resistant to extended-spectrum cephalosporins, suggesting that this combination may be effective for initial empiric therapy of pneumococcal meningitis until results of susceptibility studies are available 6.

Importance of Prompt Treatment

Prompt antibiotic treatment is crucial in improving the outcome of bacterial meningitis, and delayed lumbar punctures can reduce the chances of a positive CSF culture after starting antibiotics 7. However, even if antibiotics have been started, a lumbar puncture within 4 hours is still likely to be positive, and molecular tests for diagnosis should also be requested 7.