What is the treatment for Methicillin-sensitive Staphylococcus aureus (MSSA) empyema?

From the Guidelines

Treatment for methicillin-sensitive Staphylococcus aureus (MSSA) empyema requires both antibiotic therapy and drainage of the infected pleural space, with the recommended antibiotic regimen being intravenous nafcillin or oxacillin at 2 grams every 4 hours for adults, or cefazolin 2 grams every 8 hours if the patient has a non-anaphylactic penicillin allergy, as suggested by the Infectious Diseases Society of America guidelines 1.

Key Considerations

• The choice of antibiotic should be based on the patient's allergy history and the susceptibility of the MSSA isolate.
• Treatment duration should be 2-6 weeks depending on clinical response, with consideration for transitioning to oral therapy (such as dicloxacillin 500 mg four times daily or cephalexin 500 mg four times daily) after clinical improvement 1.
• Drainage is essential and can be accomplished via tube thoracostomy, video-assisted thoracoscopic surgery (VATS), or open thoracotomy depending on the complexity of the empyema.
• For loculated empyema, intrapleural fibrinolytics like tissue plasminogen activator (tPA) combined with DNase may be beneficial.
• Surgical intervention is often necessary for organized empyema or when drainage via chest tube is inadequate.

Rationale

MSSA empyema requires a dual approach of antibiotic therapy and drainage because antibiotics alone cannot penetrate the thick purulent material in the pleural space, and drainage without appropriate antimicrobial coverage risks persistent infection or recurrence.

Additional Considerations

• The American Heart Association recommends against the use of gentamicin for treatment of NVE caused by MSSA or MRSA 1.
• The Infectious Diseases Society of America recommends against the use of combination therapy with vancomycin and an antistaphylococcal β-lactam antibiotic for patients with S aureus bacteremia until oxacillin susceptibility is known 1.

From the FDA Drug Label

Nafcillin is indicated in the treatment of infections caused by penicillinase-producing staphylococci which have demonstrated susceptibility to the drug. 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

For the treatment of MSSA empyema,

• Nafcillin 2 can be used as it is effective against penicillinase-producing staphylococci, including MSSA.
• Clindamycin 3 can also be considered as it is indicated for the treatment of empyema caused by susceptible strains of Staphylococcus aureus. It is essential to perform culture and susceptibility tests to determine the causative organism and its susceptibility to the chosen antibiotic.

From the Research

Mssa Empyema Treatment

• The treatment of methicillin-susceptible Staphylococcus aureus (MSSA) empyema typically involves a combination of antibiotics and drainage of the pleural space 4.
• The initial choice of antibiotics depends on whether the empyema is community-acquired or nosocomial, and clinicians must recognize that culture results often do not reflect the full disease process 4.
• Antibiotics alone are rarely successful and can be justified only in specific circumstances, with early drainage with or without intrapleural fibrinolytics usually required 4.
• In cases of empyema necessitans, which is a rare phenomenon where the empyema extends through the parietal pleura and into the subcutaneous tissue of the chest wall, prompt diagnosis and treatment are crucial 5.
• The choice of antibiotic for MSSA infections, including empyema, is important, with studies suggesting that cefazolin may be a suitable alternative to traditional antistaphylococcal antibiotics such as nafcillin or oxacillin 6, 7.
• Ceftriaxone has also been evaluated as a potential treatment option for MSSA infections, with some studies suggesting that it may be associated with a lower risk of toxicity compared to traditional antistaphylococcal antibiotics 8.

Antibiotic Options

• Cefazolin: may be a suitable alternative to traditional antistaphylococcal antibiotics such as nafcillin or oxacillin for the treatment of MSSA infections, including empyema 6, 7.
• Ceftriaxone: may be associated with a lower risk of toxicity compared to traditional antistaphylococcal antibiotics, and may be a consideration for definitive therapy of MSSA infection 8.
• Nafcillin or oxacillin: traditional antistaphylococcal antibiotics that are commonly used to treat MSSA infections, including empyema 6, 7.

Treatment Approach

• Early drainage with or without intrapleural fibrinolytics is usually required for the treatment of MSSA empyema 4.
• Antibiotics alone are rarely successful and can be justified only in specific circumstances 4.
• A multidisciplinary approach to treatment, including collaboration between clinicians and other healthcare professionals, is important for optimal patient outcomes 4.