Cephalexin Use in Clinical Practice
Common Indications and Antimicrobial Spectrum
- The American College of Cardiology and the Infectious Diseases Society of America recommend cephalexin as a first-line treatment for skin and soft tissue infections, particularly cellulitis without purulence, where streptococci and methicillin-sensitive Staphylococcus aureus are the predominant pathogens 1, 2
- Cephalexin is effective against gram-positive organisms including streptococci and methicillin-sensitive Staphylococcus aureus, with a strength of evidence based on clinical guidelines 1, 5
- The American Heart Association suggests cephalexin as an alternative to amoxicillin for endocarditis prophylaxis in penicillin-allergic patients (without anaphylaxis history) undergoing dental procedures, based on moderate evidence 3, 4
Clinical Scenarios to Avoid Cephalexin
- Infections suspected to be caused by MRSA should avoid cephalexin, as it has no activity against this pathogen, according to clinical guidelines 5
- Animal bite wounds should avoid cephalexin due to its poor activity against Pasteurella multocida, based on clinical evidence 1
- Patients with a history of anaphylaxis, angioedema, or urticaria with penicillins should avoid cephalexin due to potential cross-reactivity, as recommended by the American College of Cardiology 3, 4
- Catheter-associated asymptomatic bacteriuria should not be treated with cephalexin, as it may lead to antimicrobial resistance, according to the Infectious Diseases Society of America 6, 7