ได้ส่งบทความเรื่อง "Dexamethasone to prevent neurologic complications of bacterial meningitis in adults" จาก Up To Date ไปให้คุณหมอซาฟารีทาง email แล้วค่ะ เพราะมีคำตอบสำหรับคำถามที่คุณหมอซาฟารียังข้องใจอยู่
สำหรับคำถาม: S. pneumoniae ใน community โดยเฉพาะภาคใต้ดื้อยามากไหมครับ ข้อนี้ตอบไม่ได้ค่ะเพราะการทำ susceptibility ของ pneumococci ต้องใช้ e-test ทั้ง penicillin และ cefotaxime/ceftriaxone
ขอส่ง SUMMARY AND RECOMMENDATIONS จาก UpTo Date สำหรับผู้ที่สนใจค่ะ
SUMMARY AND RECOMMENDATIONS (UpTo Date) Early intravenous administration of glucocorticoids (usually dexamethasone) has been evaluated as adjuvant therapy in an attempt to diminish the rate of hearing loss and other neurologic complications as well as mortality in selected patients with bacterial meningitis. The efficacy of dexamethasone therapy varies in developed and developing countries.
When indicated, dexamethasone is given 15 to 20 minutes before or at the time of antibiotic administration. Two dose regimens have shown efficacy: 0.15 mg/kg every six hours for four days in the European trial and 0.4 mg/kg every 12 hours for four days in the Vietnamese trial.
For adults in the developed world with known or suspected pneumococcal meningitis, we recommend administration of dexamethasone (Grade 1B). For all other adults in the developed world with confirmed or suspected bacterial meningitis, we suggest not administering dexamethasone (Grade 2B).
For adults from areas of the developing world with high HIV prevalence and known or suspected bacterial meningitis, we recommend not administering dexamethasone (Grade 1B).
In patients with known or suspected pneumococcal meningitis who are treated with dexamethasone, we suggest adding rifampin to the standard antibiotic regimen (vancomycin plus either ceftriaxone or cefotaxime) only if susceptibility studies show intermediate susceptibility (MIC ≥2 mcg/mL) to ceftriaxone and cefotaxime (Grade 2C). A reasonable alternative is to initiate rifampin and then discontinue it if the isolate is susceptible to the cephalosporin.
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Effect on antibiotic regimen There is a potential problem with the use of dexamethasone in patients with possible penicillin-resistant pneumococcal meningitis. Such patients are typically treated with vancomycin plus either ceftriaxone or cefotaxime pending susceptibility results. However, the entry of vancomycin into the CSF may be reduced by the decrease in inflammation with dexamethasone.
This issue was addressed in a rabbit model of penicillin- and cephalosporin-resistant pneumococcal meningitis. Dexamethasone substantially reduced the penetration of vancomycin into the CSF, resulting in a delay in CSF sterilization that was not seen in rabbits not treated with dexamethasone. In comparison, rifampin penetration into the CSF was not affected by dexamethasone and the combination of rifampin and ceftriaxone produced prompt bacteriologic cure.
The applicability of these experimental findings in rabbits to bacterial meningitis in humans in uncertain. Therapeutic CSF concentrations of vancomycin in the CSF were evaluated in a study of 13 adults with pneumococcal meningitis who were treated with dexamethasone and vancomycin (15 mg/kg loading dose followed by a continuous infusion of 60 mg/kg per day in adults) plus ceftriaxone or cefotaxime. The mean CSF vancomycin concentration was 7.2 mcg/mL (range 3.1 to 22.3 mcg/mL), which is higher than the MIC of vancomycin for S. pneumoniae (0.25 to 1.0 mcg/mL).
The CSF vancomycin concentrations were directly related to the serum vancomycin concentrations, suggesting that high doses of vancomycin are required to achieve effective CSF vancomycin concentrations. However, it is not certain how the findings with a constant vancomycin infusion used in this study apply to the more common regimen of two to four divided daily doses. Furthermore, since there was no control group, this study did not address the issue of whether dexamethasone interferes with vancomycin penetration into the CSF.
The recommended dose of vancomycin in the 2004 IDSA practice guidelines was 30 to 45 mg/kg per day in adults. However, initial treatment failures have occurred in adults treated solely with vancomycin at a dose of 30 mg/kg per day.
Posted by : cpantip , Date : 2010-09-06 , Time : 10:25:20 , From IP : 172.29.3.68
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