What is the choice and duration of therapy for Streptococcus anginosus (S. anginosus) empyema?

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From the FDA Drug Label

Clindamycin Injection, USP is indicated in the treatment of serious infections caused by susceptible strains of the designated organisms in the conditions listed below: Lower respiratory tract infections including pneumonia, empyema, and lung abscess caused by anaerobes, Streptococcus pneumoniae, other streptococci (except E. faecalis), and Staphylococcus aureus

  • The FDA drug label for clindamycin indicates it is used to treat empyema caused by susceptible strains of streptococci.
  • However, it does not specifically address strep anginosus or the duration of therapy for this condition.
  • The label recommends that bacteriologic studies should be performed to determine the causative organisms and their susceptibility to clindamycin, and that indicated surgical procedures should be performed in conjunction with antibiotic therapy 1.
  • Based on this information, clindamycin may be a suitable choice for the treatment of strep anginosus empyema, but the duration of therapy should be determined based on the individual patient's response and the results of bacteriologic studies.

From the Research

For Streptococcus anginosus group (SAG) empyema, the recommended treatment involves both surgical drainage and antimicrobial therapy, with a first-line antibiotic regimen of a beta-lactam such as ampicillin-sulbactam or piperacillin-tazobactam, often combined with metronidazole for anaerobic coverage, as supported by the most recent study 2. The choice of therapy should be guided by susceptibility testing, and treatment duration typically ranges from 2-6 weeks, with most cases requiring 3-4 weeks of therapy.

  • Initial IV antibiotics should be given for at least 1-2 weeks, followed by oral step-down therapy based on susceptibility testing.
  • Common oral options include amoxicillin-clavulanate or clindamycin.
  • SAG organisms are part of the normal oral flora but can cause serious infections when they reach normally sterile sites, and they often form abscesses and may be found in polymicrobial infections, as noted in 3 and 2.
  • These organisms are generally susceptible to penicillins, but resistance patterns can vary, making susceptibility testing important for guiding definitive therapy, as highlighted in 4 and 2.
  • The most recent study 2 found that overall susceptibility to penicillin was 91%, and beta-lactam antibiotics are the drug of choice, with additional coverage for anaerobic and gram-negative bacteria considered for intra-abdominal collection and solid or organ abscesses.
  • Another study 5 reported a case of SAG empyema that was treated with vancomycin after initial broad-spectrum antibiotics, and the patient showed clinical improvement postoperatively.
  • The importance of evaluating the microbiota in the lower respiratory tract for diagnosing SAG infections is also highlighted in 6.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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