Penicillins meningitis treatment

The natural and semi ynthetic penicillins are used in tire treatment of bacterial infections due to susceptible microorganisms. Fbnicillins may be used to treat infections such as urinary tract infections, septicemia, meningitis, intra-abdominal infection, gonorrhea, syphilis, pneumonia, and other respiratory infections. Examples of infectious microorganisms (bacteria) that may respond to penicillin therapy include gonococci, staphylococci,... 

Penicillin is the dmg of choice for the treatment of group B streptococcal, meningococcal and pneumococcal infections but, as discussed earlier, CSF concentrations of penicillin are significantly influenced by the intensity of the inflammatoiy response. To achieve therapeutic concentrations within the CSF, high dosages are required, and in the case of pneumococcal meningitis should be continued for 10-14 days. 

High-dose penicillin G traditionally has been the drug of choice for the treatment of pneumococcal meningitis. However, due to increases in pneumococcal resistance, the preferred empirical treatment now includes a third-generation cephalosporin in combination with vancomycin.13 All CSF isolates should be tested for penicillin and cephalosporin resistance by methods endorsed by the CLSI. Once in vitro sensitivity results are known, therapy may be tailored (Table 67-3). Patients with a history of type I penicillin allergy or cephalosporin allergy may be treated with vancomycin. Treatment should be continued for 10 to 14 days, after which no further maintenance therapy is required. Antimicrobial prophylaxis is not indicated for close contacts. 

There is concern regarding administration of dexamethasone to patients with pneumococcal meningitis caused by penicillin- or cephalosporin-resistant strains, for which vancomycin would be required. Animal models indicate that concurrent steroid use reduces vancomycin penetration into the CSF by 42% to 77% and delays CSF sterilization due to reduction in the inflammatory response.23 Treatment failures have been reported in adults with resistant pneumococcal meningitis who were treated with dexamethasone, but the risk-benefit of using dexamethasone in these patients cannot be defined at this time. Animal models indicate a benefit of adding rifampin in patients with resistant pneumococcal meningitis whenever dexamethasone is used.21,23... 

Aggressive, early intervention with high-dose IV crystalline penicillin G, 50,000 units/kg every 4 hours, is usually recommended for treatment of N. meningitidis meningitis. 

Chloramphenicol may be used in place of penicillin G. Several third-generation cephalosporins (e.g., cefotaxime, ceftizoxime, ceftriaxone, and cefuroxime) approved for the treatment of meningitis are acceptable alternatives to penicillin G (Table 36-5). Meropenem and fluoroquinolones are suitable alternatives for treatment ofpenidUin-nonsusceptible meningococci. 

When prescribing one of the penicillin G depot formulations, practitioners must individualize treatment to clinical and microbial conditions. Some long-acting formulations may not maintain adequate plasma and tissue concentrations to treat specific organisms or infections. For acute streptococcal meningitis, the goal is rapid... 

The answer is e. (Hardman, pp 1094—1095.) Penicillins were used in the treatment of meningitis because of their ability to pass across an inflamed blood-brain barrier. The third-generation cephalosporin, ceftriaxone, is preferred because it is effective against P-lactamase producing strains of H. influenzae that may cause meningitis in children. 

Cephalosporins are important bactericidal broad spectrum (3-lactam antibiotics used for the treatment of septicaemia, pneumonia, meningitis, urinary tract infections, peritonitis and biliary tract infections. They are obtained from fungus Cephalosporium acremonium and are chemically related to penicillin. It consists of beta lactam ring fused to a dihydrothiazine ring. 

Because of potential toxicity, bacterial resistance, and the availability of many other effective alternatives, chloramphenicol is rarely used. It may be considered for treatment of serious rickettsial infections such as typhus and Rocky Mountain spotted fever. It is an alternative to a B-lactam antibiotic for treatment of meningococcal meningitis occurring in patients who have major hypersensitivity reactions to penicillin or bacterial meningitis caused by penicillin-resistant strains of pneumococci. The dosage is 50-100 mg/kg/d in four divided doses. 

See footnote 3 in Table 51-2 for guidelines on the treatment of penicillin-resistant pneumococcal meningitis. 

Rifampin is used in a variety of other clinical situations. An oral dosage of 600 mg twice daily for 2 days can eliminate meningococcal carriage. Rifampin, 20 mg/kg/d for 4 days, is used as prophylaxis in contacts of children with Haemophilus influenzae type b disease. Rifampin combined with a second agent is used to eradicate staphylococcal carriage. Rifampin combination therapy is also indicated for treatment of serious staphylococcal infections such as osteomyelitis and prosthetic valve endocarditis. Rifampin has been recommended also for use in combination with ceftriaxone or vancomycin in treatment of meningitis caused by highly penicillin-resistant strains of pneumococci. 

In the treatment of entero-coccal endocarditis with penicillin and streptomycin or cryptococcal meningitis infections with amphotericin B in combination with flucytosine. 

Neither doxycycline nor a fluoroquinolone may reach therapeutic levels in the cerebrospinal fluid. Therefore, ciprofloxacin augmented with chloramphenicol, rifampin, or penicillin is the treatment of choice for suspected or confirmed anthrax meningitis (4). 

B. anthracis typically is susceptible to penicillin, amoxicillin, erythromycin, doxycycline, ciprofloxacin, and chloramphenicol. The bioterrorism-related strain was susceptible to the fluoroquinolones, rifampin, tetracycline, vancomycin, imipenem, meropenem, chloramphenicol, clindamycin, and the aminoglycosides. However, the strain was resistant to third-generation cephalosporins and trimethoprim-sulfamethoxazole. Ciprofloxacin or doxycycline plus one or two of the aforementioned antibiotics is the currently recommended regimen for the treatment of inhalational anthrax, but doxycycline is not recommended for the treatment of anthrax meningitis owing to poor CNS penetration and recent in vitro resistance. ... 

Florey was good enough to give me his whole stock of penicillin to try on this, the first case of meningitis to be treated. After a few days treatment with intramuscular and intrathecal (i.e., directly into the blood vessels of the brain) injections the patient was out of danger and he made an uneventful recovery. 

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