Emergence of Resistance

Emergence of resistance on therapy is uncommon, occurring in 5–10% of infections treated.

Emergence of resistance to beta-lactams while on therapy with these agents occurs in ~20% of patients infected with organisms with inducible beta-lactamases (Serratia, Enterobacter, Citrobacter, Acinetobacter); beta-lactams are best avoided in these patients if other options are available.

Emergence of resistance is more common in pneumonia and osteomyelitis due to decreased antibiotic penetration at these sites; attention should be given to appropriate dosing in these patients.

The addition of additional agents may lead to increased toxicity from adverse drug reactions without preventing emergence of resistance.