IDSA Issues MRSA Treatment Guidelines

The Infectious Diseases Society of America (IDSA) has published its first set of guidelines for the treatment of MRSA infections in both adults and children.

Published in Clinical Infectious Diseases, the guidelines address issues related to the use of vancomycin therapy in the treatment of MRSA infections, including dosing and monitoring, current limitations of susceptibility testing, and the use of alternate therapies for those patients with vancomycin treatment failure and infection due to strains with reduced susceptibility to vancomycin.

One of the primary topics addressed by the guidelines is the management of skin and soft-tissue infections (SSTIs) in the era of community-associated MRSA.

In terms of SSTIs, Catherine Liu, MD, of the University of California, San Francisco, and colleagues recommend the following:

• For a cutaneous abscess, incision and drainage is the primary treatment. For simple abscesses or boils, incision and drainage alone is likely to be adequate, but additional data are needed to further define the role of antibiotics, if any, in this setting.
• Antibiotic therapy is recommended for abscesses associated with the following conditions: severe or extensive disease or rapid progression in presence of associated cellulitis, signs and symptoms of systemic illness, associated comorbidities or immunosuppression, extremes of age, abscess in an area difficult to drain, associated septic phlebitis, and lack of response to incision and drainage alone.
• For outpatients with purulent cellulitis, empirical therapy for CA-MRSA is recommended pending culture results. Empirical therapy for infection due to β-hemolytic streptococci is likely to be unnecessary. Five to 10 days of therapy is recommended but should be individualized on the basis of the patient's clinical response.
• For outpatients with nonpurulent cellulitis, empirical therapy for infection due to β-hemolytic streptococci is recommended. The role of CA-MRSA is unknown. Empirical coverage for CA-MRSA is recommended in patients who do not respond to β-lactam therapy and may be considered in those with systemic toxicity. Five to 10 days of therapy is recommended but should be individualized on the basis of the patient's clinical response.
• For empirical coverage of CA-MRSA in outpatients with SSTI, oral antibiotic options include the following: clindamycin, trimethoprim-sulfamethoxazole (TMP-SMX), a tetracycline (doxycycline or minocycline), and linezolid. If coverage for both β-hemolytic streptococci and CA-MRSA is desired, options include the following: clindamycin alone or TMP-SMX or a tetracycline in combination with a β-lactam or linezolid alone.
• The use of rifampin as a single agent or as adjunctive therapy for the treatment of SSTI is not recommended.
• For hospitalized patients with complicated SSTI, in addition to surgical debridement and broad-spectrum antibiotics, empirical therapy for MRSA should be considered pending culture data. Options include the following: intravenous (IV) vancomycin, oral or IV linezolid 600 mg twice daily, daptomycin 4 mg/kg/dose IV once daily, telavancin 10 mg/kg/dose IV once daily, and clindamycin 600 mg IV or PO three times a day. A β-lactam antibiotic may be considered in hospitalized patients with nonpurulent cellulitis with modification to MRSA-active therapy if there is no clinical response. Seven to 14 days of therapy is recommended but should be individualized on the basis of the patient's clinical response.
• Cultures from abscesses and other purulent SSTIs are recommended in patients treated with antibiotic therapy, patients with severe local infection or signs of systemic illness, patients who have not responded adequately to initial treatment, and if there is concern for a cluster or outbreak.

In pediatric patients, the recommendations are as follows:

• For children with minor skin infections and secondarily infected skin lesions, mupirocin 2% topical ointment can be used.
• Tetracyclines should not be used in children <8 years of age.
• In hospitalized children with cSSTI, vancomycin is recommended. If the patient is stable without ongoing bacteremia or intravascular infection, empirical therapy with clindamycin 10—13 mg/kg/dose IV every 6–8 h (to administer 40 mg/kg/day) is an option if the clindamycin resistance rate is low with transition to oral therapy if the strain is susceptible. Linezolid 600 mg PO/IV twice daily for children ≥12 years of age and 10 mg/kg/dose PO/IV every 8 h for children <12 years of age is an alternative.

To access the full guidelines, click here.