Duricef (Cefadroxil) Activity Against Cutibacterium acnes and Streptococcus agalactiae
Duricef (cefadroxil) is effective against Streptococcus agalactiae (Group B Streptococcus) but has no clinically relevant activity against Cutibacterium acnes (formerly Propionibacterium acnes).
Activity Against Streptococcus agalactiae (Group B Strep)
Cefadroxil demonstrates excellent bactericidal activity against Group B Streptococcus and is an appropriate treatment option for infections caused by this organism. 1
Cefadroxil exhibits strong killing activity against beta-hemolytic streptococci, including Streptococcus agalactiae (Group B), with time-dependent bactericidal effects comparable to other first-generation cephalosporins 2
Clinical studies demonstrate 91% bacterial eradication rates when cefadroxil was used against beta-hemolytic streptococci, including Group B strains 1
The drug achieves sustained serum levels due to its prolonged half-life and slow urinary excretion rate, making it effective for treating Group B streptococcal infections 1
For patients with severe penicillin allergy requiring treatment of Group B Streptococcus infections, vancomycin or clindamycin (if susceptible) are recommended alternatives rather than cephalosporins like cefadroxil due to cross-reactivity concerns 3
Group B Streptococcus remains uniformly susceptible to beta-lactam antibiotics including first-generation cephalosporins 3
Activity Against Cutibacterium acnes
Cefadroxil has no established role in treating Cutibacterium acnes infections, as this anaerobic organism requires different antimicrobial coverage.
C. acnes is an anaerobic organism that colonizes human skin and requires prolonged enrichment cultures for diagnosis 4
Documented successful treatment of C. acnes infections typically involves antibiotics with strong anaerobic coverage such as sulfamethoxazole-trimethoprim, not first-generation cephalosporins 4
First-generation cephalosporins like cefadroxil lack the anaerobic spectrum necessary to effectively treat C. acnes infections 5
The antibacterial spectrum of cefadroxil is primarily directed against aerobic Gram-positive cocci (streptococci, staphylococci) and select Gram-negative organisms, not anaerobes 5
Clinical Implications
For Group B Streptococcus infections: Cefadroxil 500mg-1g twice daily is an appropriate oral option for susceptible strains in patients without severe penicillin allergy 1
For Cutibacterium acnes infections: Alternative antibiotics with anaerobic activity must be selected; cefadroxil should not be used 4
Cefadroxil's absorption is unaffected by food, allowing flexible dosing schedules 1
The drug is well-tolerated with only 3.7% of patients reporting mild, transient side effects in clinical trials 1