Cefadroxil vs Cefixime: Spectrum and Clinical Usage

Spectrum of Activity

Cefadroxil has good activity against Streptococcus pyogenes, Streptococcus pneumoniae (penicillin-susceptible strains), and methicillin-susceptible Staphylococcus aureus 1, 2
Cefadroxil has limited gram-negative coverage, with poor activity against Haemophilus influenzae and most Enterobacteriaceae 1, 2
Cefadroxil has minimal to no anaerobic coverage 1
Cefadroxil is easily hydrolyzed by beta-lactamases, indicating poor beta-lactamase stability 1, 2
Cefixime has potent activity against H. influenzae (including beta-lactamase-producing strains), Neisseria gonorrhoeae, and most Enterobacteriaceae 1, 2, 3
Cefixime has limited activity against S. pneumoniae (penicillin-susceptible only) and no activity against staphylococci 1, 2, 3, 4
Cefixime has no clinically significant activity against drug-resistant S. pneumoniae (DRSP) 1, 2, 3, 4

Cefadroxil is indicated for skin and soft tissue infections caused by streptococci or staphylococci (community-acquired, non-MRSA) 1
Cefadroxil is indicated for pharyngitis/tonsillitis due to S. pyogenes 1
Cefadroxil is indicated for simple urinary tract infections in areas with low E. coli resistance 1
Cefixime is indicated for acute bacterial rhinosinusitis when H. influenzae is suspected, though limited pneumococcal coverage is a concern 1, 2, 3

Cefadroxil is inappropriate for infections involving H. influenzae (respiratory tract infections, otitis media) 1, 2
Cefadroxil is inappropriate for beta-lactamase-producing organisms 1, 2
Cefixime is inappropriate for empiric community-acquired pneumonia (inadequate S. pneumoniae coverage, especially DRSP) 1, 2, 3, 4
Cefixime is inappropriate for staphylococcal infections (skin/soft tissue, bacteremia) 1, 2, 3
Cefixime is inappropriate for anaerobic infections (Bacteroides fragilis) 1
Cefixime is inappropriate for enterococcal infections 1

Choose Cefadroxil when no concern for beta-lactamase-producing organisms and no gram-negative pathogen involvement is expected 3, 4
Choose Cefixime when H. influenzae is confirmed or suspected, but ensure adequate gram-positive coverage is not needed first 1
Never substitute one for the other as they address opposite ends of the bacterial spectrum—cefadroxil targets gram-positives while cefixime targets gram-negatives 1, 2, 3