Meningitis - Adults

• This is a medical emergency - see Hospital HealthPathways and consult Infectious Diseases.
• The aim is to give antimicrobials immediately once diagnosis is suspected.
• If the patient has focal neurological deficits or bacterial meningitis is suspected, dexamethasone 10 mg IV should be given with or before the first dose of antimicrobials and, if pneumococcal meningitis is confirmed, every 6 hours for 4 days. (Shown to improve neurological outcome - see Hospital HealthPathways).

Pathogens

• Common: Viruses, S. pneumoniae (notifiable), N. meningitidis (notifiable)
• Other: S. aureus, Listeria monocytogenes (notifiable), H. influenzae
• Hospital-acquired: E. coli, S. aureus, Coagulase-negative staphylococci

Drug treatment

• Duration:
  • N. meningtidis – 5 days IV
  • S. pneumoniae – 10 to 14 days IV
  • Staphylococci – 14 days IV minimum
  • Listeria monocytogenes – 21 days IV minimum

Empiric

ceftriaxone HMLSchedNZFPMLnoids Ceftriaxone F: n/a Half life: 8 hours Elimination: 50% renal and 50% biliary excretion fe: 0.5

IV 2 g every twelve hours

• fe = 0.5, consider adjusting dose if CrCl reduced.

If risk of listeria (alcoholic, diabetic, > 50 years, pregnant, or immunosuppressed):

ADD

amoxicillin HMLSchedNZFPMLnoids Amoxicillin F: 0.9 Half life: 2 hours Elimination: renal fe: 0.9

IV 2 g every four hours

• fe = 0.9, consider adjusting dose if CrCl is reduced.

If risk of S. pneumoniae (known or suspected otitis media or sinusitis, recent treatment with a beta-lactam, Gram-positive cocci seen on Gram stain, or pneumococcal antigen assay of CSF is positive):

ADD

vancomycin HMLSchedNZFPMLnoids Vancomycin F: n/a Half life: 6 hours Elimination: renal fe: 0.9 Additional points: TDM

See dosing guidelines (use high doses).

• fe = 0.9, adjust dose if CrCl reduced.
• Must be given diluted (1 g in at least 200 mL) and slowly (≤ 1000 mg/hour) to minimise infusion reactions.

Severe penicillin allergy

• No need to add additional cover for listera if risk factors are present.

Alternative regimen:

ciprofloxacin HMLSchedNZFPMLnoids Ciprofloxacin F: 0.7 Half life: 4 hours Elimination: renal fe: 0.5 Additional points: Inhibits CYP1A2 and 3A. Antacids, milk, and enteral feeds ↓ absorption.

IV 400 mg every eight hours

• fe = 0.5, consider adjusting dose if CrCl reduced.
• Inhibits CYP1A2 (strong) and 3A.
• Subject to OAT and OATP (transporter) inhibition.

AND

• fe = 0.9, adjust dose if CrCl reduced.
• Must be given diluted (1 g in at least 200 mL) and slowly (≤ 1000 mg/hour) to minimise infusion reactions.

If risk of listeria (alcoholic, diabetic, > 50 years, pregnant, or immunosuppressed):

ADD

trimethoprim+sulfamethoxazole HMLSchedNZFPMLnoids Trimethoprim+Sulfamethoxazole F: 0.8 Half life: 9 hours / 12 hours Elimination: CYP2C8/9 acetylated fe: 0.3 / 0.7 (co-trimoxazole)

IV 5 mg/kg (trimethoprim component) every six hours (round dose down to the nearest whole vial)

• fe (trimethoprim) = 0.7, fe (sulfamethoxazole) = 0.3, consider adjusting dose if CrCl reduced.
• Sulfamethoxazole is metabolised by CYP2C8/9 and conjugation.

Pathogens Known

S. pneumoniae

If susceptible to penicillin and the patient does not have a penicillin allergy:

benzylpenicillin HMLSchedNZFPMLnoids Benzylpenicillin F: n/a Half life: 1 hour Elimination: hydrolysis fe: 0.9 (Penicillin G)

IV 2.4 g (4 megaunits) every four hours

• fe = 0.8, consider adjusting dose if CrCl is reduced.

Mild penicillin allergy

• fe = 0.5, consider adjusting dose if CrCl reduced.

If resistant to penicillin or severe penicillin allergy:

• fe = 0.9, adjust dose if CrCl reduced.
• Must be given diluted (1 g in at least 200 mL) and slowly (≤ 1000 mg/hour) to minimise infusion reactions.

N. meningitidis (notifiable)

• fe = 0.5, consider adjusting dose if CrCl reduced.

Severe penicillin allergy

Consult Infectious Diseases/Clinical Microbiology

For clearance of nasopharyngeal N. meningitidis from patient and contacts:

• Inhibits CYP1A2 (strong) and 3A.
• Subject to OAT and OATP (transporter) inhibition.

OR

Listeria monocytogenes (notifiable)

• fe = 0.9, consider adjusting dose if CrCl is reduced.

Penicillin allergy

• fe (trimethoprim) = 0.7, fe (sulfamethoxazole) = 0.3, consider adjusting dose if CrCl reduced.
• Sulfamethoxazole is metabolised by CYP2C8/9 and conjugation.

Topic Code: 99219

must be prescribed or recommended by a consultant.