cefazolin + ertapenem

Cefazolin + ertapenem is a synergistic antibiotic combination therapy that demonstrates enhanced activity against methicillin-susceptible Staphylococcus aureus (MSSA) infections, particularly in cases of persistent bacteremia and endocarditis. The combination works through complementary penicillin-binding protein (PBP) inhibition, with ertapenem having exceptional affinity for PBP1 while cefazolin preferentially targets PBP2. This dual targeting of different cell wall synthesis components creates a potent synergistic effect that exceeds what would be predicted from in vitro studies alone. Clinical case series have demonstrated rapid clearance of bacteremia (often within 24 hours) in patients who had previously failed standard monotherapy.