Topical antibacterials used for acne / rosacea

Generic Name

Benzoyl Peroxide

  • Pregnancy Category C
Formulations

Bactericidal (Wolverton) Bacteriostatic (Bolognia)

  • formulations: wash, bar soap, lotion, cream, gels 2.5% – 20%
Mechanism of Action

Non-specific oxidizing activity:

  • bactericidal, also inhibits triglyceride hydrolysis; reduces inflammation; comedolytic, keratolytic
Indication / Spectrum of Activity

Broad spectrum bacteria coverage

  • Acne (targets C. acnes)
  • Rosacea (combined with clindamycin)
Side Effects
  • Irritant contact dermatitis; burning, erythema, peeling, dryness
  • Allergic contact dermatitis (uncommon 0.2-1%)
  • Bleaches fabrics, hair and other colored materials
Other
  • No resistance has been found, combination treatment with topical antibiotic reduces bacterial resistance 
  • Will degrade tretinoin if applied simultaneously, but less with gel formulation of tretinoin

Generic Name

Clindamycin

  • Pregnancy Category B
Formulations

Bacteriostatic, Bactericidal

  • 1% alcohol-based solution
  • lotion (least irritating)
  • gel
Mechanism of Action

Macrolide

  • Reversibly binds bacterial 50s ribosomal subunit, inhibits protein synthesis
Indication / Spectrum of Activity

Gram positive, MRSA, anaerobes and Gardnerella vaginalis

  • Acne (should be combined with other topical medications), folliculitis, erythrasma, periorificial dermatitis, rosacea, Fox-Fordyce
Side Effects
  • Irritant contact dermatitis, allergic contact dermatitis (rare)
  • Gram negative folliculitis
  • Pseudomembranous colitis (extremely rare with topical form)
Other
  • Avoid in patients with inflammatory bowel disease or history of C. difficile
  • Reported to be effective for pitted keratolysis 
  • Has neuromuscular blocking effects and should be used in caution in patients receiving neuromuscular blockers

Generic Name

Erythromycin

  • Pregnancy Category B
Formulations
  • Bactericidal
  • Gel
  • solution
  • pads
Mechanism of Action

Macrolide

  • Reversibly binds bacterial 50s ribosomal subunit, inhibits protein synthesis
  • Anti-inflammatory
Indication / Spectrum of Activity

Gram positive:

  • Acne, Rosacea, Erythrasma, Pitted Keratolysis
Side Effects
  • Irritant contact dermatitis, eye irritation, allergic contact dermatitis, resistance,
  • Gram negative folliculitis
  • Generalized urticarial reactions (rare)
Other
  • C. acnes resistance in 60-100%, ways to likelihood / overcome resistance are 1) Increase concentration to 4%; 2) Add zinc; 3) Add benzoyl peroxide

Generic Name

Metronidazole

  • Pregnancy Category B
Formulations
  • 0.75% gel/cream or 1% cream
Mechanism of Action
  • Disruption of DNA and inhibition of nucleic acid synthesis
  • Anti-inflammatory
Indication / Spectrum of Activity

Gram positive, Gram negative, anaerobes, protozoa, Demodex

  • Rosacea (including rosacea lid blepharitis)
  • Ulcers/fungating tumors (for odor)
  • Seborrheic dermatitis
Side Effects
  • Irritant contact dermatitis, watery eyes, metallic taste in mouth, numbness, paresthesias reported, 
  • Allergic contact dermatitis rare (can cross react with MCI/MI, and those allergic to oral form)
Other
  • Ineffective against C. acnes, Staphylococcus spp, Streptococcus spp., fungi and Demodex
  • Effective for pustules, papules > erythema in Rosacea, but not telangiectasias and rhinophyma

Generic Name

Azelaic acid

  • Pregnancy Category B
Formulations

Bacteriostatic > bactericidal 

  • 20% cream
  • 15% gel (Finacea)
Mechanism of Action
  • Disruption of mitochondrial respiration and DNA synthesis + inhibition of protein synthesis Comedolytic
  • Competitive inhibitor of tyrosinase (anti- pigmentary effect – see Other section)
Indication / Spectrum of Activity
  • Broad antimicrobial 
  • Acne, rosacea, perioral dermatitis, plaque psoriasis, disorders of pigmentation (post-inflammatory hyperpigmentation, melasma)
Side Effects
  • Itching, burning, scaling 
  • Rare allergic contact dermatitis (propylene glycol)
  • Rarely hypopigmentation, hypertrichosis
Other
  • Dicarboxylic acid derivative 🡪 inhibitor of tyrosinase and decreases ultraviolet B induced IL-1, IL-6, TNF, normalizes keratinization & decreases melanocyte proliferation & neutrophil production of reactive oxygen species

Generic Name

Dapsone

  • Pregnancy Category C
Formulations

Bacteriostatic 

  • 5% gel
Mechanism of Action
  • Neutrophil functioning, inhibition of dihydropteroate synthetase and nucleic acid synthesis 
  • Interferes with neutrophils; inhibits IL-8 release, chemotaxis; inhibits neutrophilic myeloperoxidase, and TNF-α
Indication / Spectrum of Activity

Acne (FDA approved); consider use in neutrophilic dermatoses; can use in pemphigus vulgaris for oral lesions

Side Effects
  • Dryness, erythema, sunburn
  • orange-brown discoloration with benzoyl peroxide (stains clothing, not skin)
  • Hemolysis theoretically but none reported in long term studies (Wolverton)
  • Occasional anemia/rare methemoglobinemia (Bolognia)
Other
  • G6PD testing not required prior to topical use
  • Activity against Mycobacterium, PCP, P. falciparum, Leishmania and Toxoplasma

Generic Name

Sodium Sulfacetamide

  • Pregnancy Category C
Formulations

Bacteriostatic

  • lotion, solution, foam, pads; mixed with sulfur
Mechanism of Action
  • Inhibits bacterial dihydropteroate synthetase
Indication / Spectrum of Activity
  • Acne, rosacea
Side Effects
  • Mild/moderate dryness, transient pruritus 
  • Orange-brown discoloration with benzoyl peroxide (stains clothing, not skin)
Other
  • Available in rosacea products with precipitated sulfur (sulfur is also keratolytic)
  • May cross-react if allergy to systemic sulfonamide antibiotics