Managing rosacea: a review of the use of metronidazole alone and in combination with oral antibiotics.

BACKGROUND: Rosacea is an extremely common chronic dermatosis affecting an estimated 14 million Americans. Rosacea is most commonly managed with topical metronidazole, sometimes in combination with oral antibiotics. PURPOSE: To review published studies about topical metronidazole therapy for rosacea, both as a monotherapy and in conjunction with oral antibiotics. METHODS: Medline searches were conducted for clinical trials using metronidazole, tetracycline, and doxycycline for rosacea. RESULTS: Topical metronidazole has been well studied as a rosacea therapy. Twice-daily dosing of metronidazole 1.0% cream is as effective as 250 mg tetracycline twice daily. Metronidazole 1.0% gel used once daily is as effective as azelaic acid 15% gel dosed twice daily. When dosed at subantimicrobial levels, doxycycline 20 mg taken twice daily is effective in decreasing inflammatory lesions and erythema associated with rosacea. Metronidazole 0.75% lotion is more effective when used in combination with doxycycline 20 mg dosed twice daily. DISCUSSION: Metronidazole in 0.75% strength lotion, cream, and gel and 1.0% metronidazole cream and gel are all efficacious in treating rosacea. Combination treatment with oral antibiotics at both antimicrobial and subantimicrobial doses is an efficacious means of treating rosacea. Maintenance treatment with topical metronidazole decreases relapses and allows for longer intervals between flares.