University:
Michigan State University
Course:
MED 618 | Infectious Diseases Clerkship
Academic year:

2021
Views:

210

Pages:

33
Author:

Caroline Mcfarland

Therapy of Meningitis 1 Therapy of Meningitis Goals of treatment: 1. Eradication of infection. 2. Amelioration of signs and symptoms. 3. Prevention of the development of neurologic sequelae, such as seizures, deafness, coma, and death. 2 Therapy of Meningitis It is important to: 1) Prevent the disease through timely introduction of vaccination and chemoprophylaxis. 2) Understand antibiotic selection and the issues surrounding antibiotic penetration into the central nervous system. • Until a pathogen is identified, immediate empirical antibiotic coverage is needed. 3 Therapy of Meningitis • The first dose of antibiotics should NOT be withheld, even when lumbar puncture is delayed or neuro-imaging is being performed; because changes in the CSF after antibiotic administration usually take up to 12 to 24 hours to occur. • Continued therapy should be based on the assessment of clinical improvement, culture, and susceptibility testing results. • Once a pathogen is identified, antibiotic therapy should be tailored to the specific pathogen. 4 Etiologies and Empirical Therapy by Age Group Age Most Likely Organisms Empirical Therapy <1 month Streptococcus agalactiae Gram-negative enterics (E. coli, Klebsiella spp, Enterobacter spp) L. Monocytogenes Ampicillin + cefotaxime or Ampicillin + aminoglycoside 1-23 months S. pneumoniae N. meningitidis H. influenzae S. agalactiae Vancomycin + 3rd generation cephalosporin (cefotaxime or ceftriaxone) Vancomycin to cover penicillin-resistant S. pneumoniae 2-50 years N. meningitidis S. pneumoniae Vancomycin + 3rd generation cephalosporin (cefotaxime or ceftriaxone) Vancomycin to cover penicillin-resistant S. pneumoniae >50 years S. pneumoniae N. meningitidis Gram-negative enterics (E. coli, Klebsiella spp, Enterobacter spp) L. monocytogenes Vancomycin + ampicillin + 3rd generation cephalosporin (cefotaxime or ceftriaxone) Vancomycin to cover penicillin-resistant S. pneumoniae 5 Penetration of Antimicrobial Agents into the CSF Therapeutic Levels in CSF With/Without Inflammation: Acyclovir, Levofloxacin, Chloramphenicol, Linezolid, Ciprofloxacin, Metronidazole, Fluconazole, Moxifloxacin, Flucytosine, Pyrazinamide, Foscarnet, Rifampin, Fosfomycin, Sulfonamides, Ganciclovir, Trimethoprim, Isoniazid, Voriconazole Therapeutic Levels in CSF With Inflammation of Meninges: Ampicillin ± sulbactam, Imipenem, Aztreonam, Meropenem, Cefepime, Nafcillin, Cefotaxime, Ofloxacin, Ceftazidime, Penicillin G, Ceftriaxone, Piperacillin/tazobactam, Cefuroxime, Pyrimethamine, Colistin, Quinupristin/dalfopristin, Daptomycin, Ticarcillin ± clavulanic acid, Ethambutol, Vancomycin 6 Antimicrobial Agents by Organism Gram-Positive Organisms: Streptococcus pneumoniae: duration 10-14 days. 1. Penicillin susceptible: • Antibiotics of First Choice: Penicillin G or Ampicillin. • Alternatives: Cefotaxime, Ceftriaxone, Cefepime or Meropenem. 2. Penicillin resistant: • Antibiotics of First Choice: Vancomycin + Cefotaxime or Ceftriaxone. • Alternatives: Moxifloxacin. 7 Antimicrobial Agents by Organism 3. Ceftriaxone resistant: • Antibiotics of First Choice: Vancomycin + Cefotaxime or Ceftriaxone. • Alternative: Moxifloxacin. Staphylococcus aureus: duration 14-21 days. 1. Methicillin susceptible: • Antibiotics of First Choice: Nafcillin or Oxacillin. • Alternative: Vancomycin or Meropenem. 8 Antimicrobial Agents by Organism 2. Methicillin resistant: • Antibiotics of First Choice: Vancomycin. • Alternative: TMP-SMX or Linezolid. Group B Streptococcus: duration 14-21 days. • Antibiotics of First Choice: Penicillin G or Ampicillin ± Gentamicin. • Alternative: Ceftriaxone or Cefotaxime. Staph. epidermidis: duration 14-21 days. • Antibiotics of First Choice: Vancomycin. • Alternative: Linezolid. 9 Antimicrobial Agents by Organism Listeria monocytogenes: duration ≥ 21 days • Antibiotics of First Choice: Penicillin G or Ampicillin ± Gentamicin. • Alternative: Trimethoprim-sulfamethoxazole, Meropenem. 10 Antimicrobial Agents by Organism Gram-Negative Organisms: Neisseria meningitidis: duration 7-10 days. 1. Penicillin susceptible: • Antibiotics of First Choice: Penicillin G or Ampicillin. • Alternatives: Cefotaxime or Ceftriaxone. 2. Penicillin resistant: • Antibiotics of First Choice: Cefotaxime or Ceftriaxone. • Alternatives: Meropenem or Moxifloxacin. 11 Antimicrobial Agents by Organism Haemophilus influenzae: duration 7-10 days. 1. β-lactamase negative: • Antibiotics of First Choice: Ampicillin. • Alternatives: Cefotaxime, Ceftriaxone, Cefepime or Moxifloxacin. 2. β-lactamase positive: • Antibiotics of First Choice: Cefotaxime or Ceftriaxone. • Alternatives: Cefepime or Moxifloxacin. 12 Antimicrobial Agents by Organism Enterobacteriaceae (Including E. coli and Klebsiella spp.): duration 21 days. • Antibiotics of First Choice: Cefotaxime or Ceftriaxone. • Alternatives: Cefepime, Moxifloxacin, Meropenem or Aztreonam. Pseudomonas aeruginosa: duration 21 days. • Antibiotics of First Choice: Cefepime or Ceftazidime ± Tobramycin. • Alternatives: Ciprofloxacin, Meropenem, Piperacillin + Tobramycin, Colistin sulfomethate, Aztreonam. 13 Therapy of Meningitis • Supportive care (administration of fluids, electrolytes, antipyretics, and analgesics ) is critically important. • Venous thromboembolism prophylaxis and intracranial pressure (ICP) monitoring may be needed. • Mannitol 25% or hypertonic 3% saline may be needed to maintain an ICP of less than 15 mm Hg. • Appropriate antibiotic therapy (empirical or definitive) should be started as soon as possible. 14 Dexamethasone as an Adjunctive Treatment for Bacterial Meningitis • Dexamethasone is a commonly used adjunctive therapy in the treatment of meningitis. • Corticosteroids inhibit the production of TNF, PAF and IL-1, potent proinflammatory cytokines. • They also reduce cerebral edema, high ICP, neuronal injury, and vasculitis. • Some clinical studies have shown that treatment with corticosteroids reduces both mortality and neurological sequelae in adults with communityacquired bacterial meningitis. 15 Dexamethasone as an Adjunctive Treatment for Bacterial Meningitis • Corticosteroid use in bacterial meningitis was associated with lower rates of severe hearing loss, and neurological sequelae, but did not reduce overall mortality (some other studies). • Current recommendations are with the use of adjunctive dexamethasone in infants and children (6 weeks of age and older) with H. influenza meningitis. • The recommended intravenous dose is 0.15 mg/kg every 6 hours for 2 to 4 days, initiated 10 to 20 minutes prior to or concomitant with, but not after, the first dose of antibiotics. 16 Dexamethasone as an Adjunctive Treatment for Bacterial Meningitis • With adjunctive dexamethasone use, signs and symptoms of GI bleeding and hyperglycemia, should be monitored carefully. • However, routine use of dexamethasone in meningitis is still controversial. 17 Bacterial Brain Abscess Etiology: 1. Those arising from spread of infection from oropharynx, middle ear, and paranasal sinuses are commonly caused by streptococci and oral anaerobes (Actinomyces spp., Bacteroides spp., Fusobacterium spp., Peptostreptococcus). 2. Staphylococci, aerobic and gram-negative bacilli are commonly involved in postoperative abscesses or those following head trauma. 18 Bacterial Brain Abscess 3. P. aeruginosa and Nocardia spp. can cause brain abscesses but are more commonly seen in immunocompromised patients. • Brain abscesses are commonly polymicrobial, thus, empiric antimicrobial therapy should include antibiotics with activity against gram-positive, gram-negative, and anaerobic organisms: a) Vancomycin + a third- or fourth-generation cephalosporin + metronidazole, depending on risk factors. 19 Bacterial Brain Abscess b) A carbapenem (meropenem) could replace the cephalosporin and metronidazole. • De-escalation of therapy should be performed once a causative organism is identified. • De-escalation means changing an empiric broad-spectrum antibiotic regimen to a narrower antibiotic regimen by changing the antimicrobial agent or changing from combination therapy to monotherapy. 20 Bacterial Brain Abscess • Duration of therapy should be determined for each individual patient and should include consideration of the causative pathogen, size of abscess, use of surgical treatment, and response to therapy. • It is prolonged, usually 4-8 weeks. • United Kingdom guidelines recommend 4-6 weeks if the abscess has been drained or excised and 6-8 weeks if the abscess is treated without drainage. 21 Bacterial Brain Abscess The following categories require a longer duration of therapy (6-8 weeks or longer): 1. Patients with an organized capsule with evidence of tissue necrosis. 2. Patients with a multiloculated abscess. 3. Patients with lesions in vital locations such as the brain stem or the motor strip (particularly if not surgically drained). 4. Immunocompromised patients. 5. Needle aspiration rather than open surgical excision. 22 Bacterial Brain Abscess • Anticonvulsant therapy is recommended for at least 1 year, because seizures are common complication of brain abscesses. • The benefit of dexamethasone in the treatment of brain abscess is unclear and not routinely recommended, unless signs of cerebral edema are identified. 23 Cryptococcus neoformans • Mainly affect persons with underlying impaired immunity. • Acquired by inhalation of spores from the environment leading to CNS infection and less commonly pulmonary disease. • Rapid sterilization of CNS through rapid fungicidal activity is the main approach of induction therapy (2 - 6 weeks), followed by consolidation therapy for 8 weeks. 24 Cryptococcus neoformans • Amphotericin B was the drug of choice for the treatment of acute cryptococcal meningitis due to its rapid fungicidal activity, despite poor penetration into the CSF. • Amphotericin B (1 mg/kg/day) combined with flucytosine (100 mg/kg/day) for 2 weeks was more effective than amphotericin alone for 4 weeks, or in combination with fluconazole (400 mg twice daily) for 2 weeks in HIV-positive patients. • Voriconazole in combination with amphotericin B can be used. 25 Cryptococcus neoformans • Flucytosine is poorly tolerated, causing bone marrow suppression and GI distress. • Careful monitoring of hematologic parameters, therapeutic drug monitoring (TDM) and dose adjustment for patients with renal insufficiency are recommended to avoid flucytosine-associated toxicities. • Lipid formulations of amphotericin B at higher doses (3-5 mg/kg/day) can be used for HIV-positive patients with or predisposed to renal dysfunction and are recommended for organ-transplant recipients. 26 Mycobacterium tuberculosis • Initial regimen of four drugs for empirical treatment of M. tuberculosis is recommended. • This regimen consists of isoniazid, rifampin, pyrazinamide, and ethambutol for the first 2 months, followed by isoniazid plus rifampin for the remaining duration of therapy. • Duration of treatment 9 - 12 months or longer with multiple-drug therapy. • With rifampin-resistant strains duration may be 18 - 24 months. 27 Mycobacterium tuberculosis • The recommended therapy for HIV-positive individuals is the same as for immunocompetent patients. • Duration of treatment ≥ 24 months. • Rifabutin may replace other rifamycins (rifampin) to minimize drug interactions with protease inhibitors and nonnucleoside reversetranscriptase inhibitors. 28 Chemoprophylaxis of Meningitis • The spread of some types of bacterial meningitis can be prevented by administering prophylactic antimicrobials to contacts of patients with bacterial meningitis. • This prevents transmission of the bacteria to susceptible hosts, and eradicates the organism from the nasopharynx of those who are already colonized. • Such therapy is recommended for close contacts of patients infected with: H. influenzae or N. meningitidis. 29 Chemoprophylaxis of Meningitis • Close contacts are defined as house-hold or daycare members who sleep or eat in the same dwelling as the index patient. • Therefore, health care workers do not require chemoprophylaxis unless close contact with the patient's secretions occurs, as in mouth-tomouth resuscitation. 30 Chemoprophylaxis of Meningitis Chemoprophylaxis for Neisseria meningitidis Children < 5years Ciprofloxacin single dose 30mg/kg po (max 125mg) Children 5-12 years Ciprofloxacin 250mg po single dose Pregnant women Ceftriaxone 250mg IM stat Female adults on the oral contraceptive pill Ciprofloxacin 500mg po single dose Adults and children >12 years Ciprofloxacin 500mg po single dose Rifampin can be used, but the duration of therapy is 2 days. 31 Chemoprophylaxis of Meningitis Chemoprophylaxis for Haemophilus influenzae Infants under 1 year of age Rifampicin 10mg/kg once daily for 4 days Adults and children Rifampicin 20mg/kg once daily for 4 days up to max of 600mg/day Pregnant women Not indicated 32 Vaccination • With Haemophilus influenzae type b, pneumococcal meningitis or Neisseria meningitidis Groups C, A, Y and W135, vaccination of contacts and index may be indicated. 33

Therapy of Meningitis

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