Lecture Notes: Topical Antibiotics

The efficacy of topical antibiotics for the treatment of acne vulgaris and rosacea may be due to their direct antibiotic effect, but many of the topical antibiotics exhibit anti-inflammatory properties by suppressing neutrophil chemotactic factor or by other mechanisms.

There are concerns about the use of topical antibiotics in the treatment of acne vulgaris because of the increasing levels of antibiotic resistance to common topicals. Combining the antimicrobial benzoyl peroxide with antibiotics reduces the development of antibiotic resistance.

NAME SOURCE FORM AVAILABLE MECHANISM OF ACTION BACTERIAa Bacitracin Bacillus subtilis O Cell wall inhibitor Gr + Polymyxin B B. polymyxa O Detergent Gr - Gramicidin O Ion channel Gr + Mupirocin Pseudomonas fluorescens O Transfer RNA inhibitor Gr + Neomycin Streptomyces fradiae O 30S ribosome inhibition Gr - Tetracycline Semisyntheticb O,S 30S ribosome inhibition Gr ± Meclocycline Semisyntheticc C 30S ribosome inhibition Gr ± Erythromycin Streptococcus erythreus S,G,P,O 50S ribosome inhibition Gr ± Clindamycin Semisynthetic S,G,L 50S ribosome inhibition Chloramphenicol S. venezuelaed C 50S ribosome inhibition Fusidic acid NA Interferes with EF-G Silver sulfadiazine Synthetic C Mafenide acetate Synthetic C Enzyme inhibition Gr ± Nitrofurazone Synthetic C,S Enzyme inhibition Gr ± Metronidazole Synthetic G,C Electrochemical Anaerobes Clioquinol Synthetic C,O Unknown Broad spectrum Azelaic acid Synthetic C,G Protein synthesis inhibition Gr + Notes: C = cream;  EF-G = elongation factor G;  G = gel;  Gr + = Gram-positive;  Gr - = Gram-negative;  Gr ± = Gram-positive or -negative;  L = lotion;  NA = not available in the United States;  O = ointment;  P = pledget;  S = solution. a Bacteria refers to bacteria usually susceptible to antibiotic. b Semisynthetic from chlortetracycline, fermented from some species of Streptomyces. c Semisynthetic from tetracycline. d Now completely synthesized.

Reference: 

Fitzpatrick's Dermatology in General Medicine 7th Edition