Antibiotic Use in Penicillin-Allergic Patients

Introduction to Clindamycin Use

• The American College of Cardiology recommends clindamycin as a first choice for severe penicillin allergy, with standard dosing guidelines, for serious infections due to susceptible strains of streptococci, pneumococci, and staphylococci 1
• Clindamycin is recommended for patients with severe penicillin allergy, with approximately 1% clindamycin resistance among GAS isolates in the US 2

Dosage and Administration

• For patients with severe penicillin allergy (high risk for anaphylaxis), clindamycin 900mg IV every 8 hours is recommended if the GBS isolate is susceptible, with susceptibility testing performed before use 3
• If susceptibility is unknown or shows resistance, vancomycin should be used instead 3

Combination Therapy and Alternatives

• Clindamycin can be used as part of combination therapy with other non-beta-lactam antibiotics for severe group A streptococcal and clostridial necrotizing infections (A-II) 1
• Macrolides (erythromycin, clarithromycin) or azalides (azithromycin) can be considered for some infections if clindamycin is not appropriate 2
• Vancomycin is recommended when clindamycin cannot be used due to resistance 3

Susceptibility Testing and Resistance

• Approximately 20% of GBS isolates are resistant to clindamycin, making susceptibility testing crucial before empirical use 3
• Clindamycin resistance among GAS isolates in the US is approximately 1% 2

Special Considerations

• Clindamycin carries a higher risk of C. difficile-associated diarrhea, as highlighted in a boxed warning on the FDA label, although the reference is ignored in this context
• For surgical prophylaxis, consider broader gram-negative coverage when using clindamycin due to increased surgical site infection rates in certain procedures 3