Alternative Antibiotics for Group B Streptococcus (GBS) Infections

Assessment and Treatment

• The Centers for Disease Control and Prevention recommends determining if a patient has a high risk for anaphylaxis, such as a history of immediate hypersensitivity reactions, before selecting alternative antibiotics for GBS infections 1, 2
• Verification of reported penicillin allergy is important before selecting alternative antibiotics, as approximately 10% of persons with penicillin allergy also have immediate hypersensitivity reactions to cephalosporins 3, 2
• For non-severe penicillin allergy, the Centers for Disease Control and Prevention recommends cefazolin as an alternative, with a 2g IV initial dose, then 1g IV every 8 hours until treatment completion 1, 3
• GBS isolates remain highly susceptible to cefazolin, with minimum inhibitory concentrations consistently low 4, 1
• For severe penicillin allergy, obtaining antimicrobial susceptibility testing for clindamycin and erythromycin is recommended, if possible 1, 5
• If the isolate is susceptible to both clindamycin and erythromycin, clindamycin 900 mg IV every 8 hours is recommended 1, 5
• If susceptibility testing is not available or the isolate is resistant to clindamycin/erythromycin, vancomycin 1g IV every 12 hours is recommended 1, 5
• The Centers for Disease Control and Prevention recommends reserving vancomycin for cases where no other options exist, due to concerns about promoting antimicrobial resistance 2, 5
• Susceptibility testing should always be performed when treating GBS infections in penicillin-allergic patients, according to the Centers for Disease Control and Prevention 5

Safest Antibiotic for Pregnant Women with Severe Penicillin Allergy

Defining Severe Penicillin Allergy

• The CDC defines severe penicillin allergy as a history of anaphylaxis, angioedema, respiratory distress, or urticaria after receiving penicillin or a cephalosporin, according to the Centers for Disease Control and Prevention guidelines 6

Treatment Algorithm for Severe Penicillin Allergy in Pregnancy

Step 1: Obtain Antimicrobial Susceptibility Testing

• The CDC mandates obtaining susceptibility testing for clindamycin and erythromycin on all GBS isolates from penicillin-allergic women at high risk for anaphylaxis, as recommended by the Centers for Disease Control and Prevention 6

Step 3: Special Considerations

• The CDC recommends performing D-zone testing on GBS isolates that are erythromycin-resistant but clindamycin-susceptible from penicillin-allergic women at high risk for anaphylaxis to detect inducible clindamycin resistance, according to the Centers for Disease Control and Prevention guidelines 6