Best Answer: The erythromycin is antibacterial and will prevent the acne from coming back by killing off the acne spores under your skin. I'm on it now and its the only thing thats ever worked for me. I find benzoyl peroxide to irritate my skin and make me break out so that's an interesting combo. Anyway. Erythromycin and benzoyl peroxide topical gel , 3%;5% also contains benzoyl peroxide for topical use. Benzoyl peroxide is an antibacterial and keratolytic agent. Erythromycin and Benzoyl Peroxide Topical Gel USP is indicated for the topical treatment of acne vulgaris. Contraindications Erythromycin and Benzoyl Peroxide Topical Gel USP is contraindicated in those individuals who have shown hypersensitivity to any of its components. ERYTHROMYCIN is a macrolide antibiotic. It is used to treat certain kinds of bacterial infections. It will not work for colds, flu, or other viral infections. Each gram of Erythromycin and Benzoyl Peroxide Topical Gel USP contains, as dispensed, 30 mg (3%) of erythromycin and 50 mg (5%) of benzoyl peroxide in a base of purified water USP, carbomer 940 NF, ethyl alcohol 20%, sodium hydroxide NF, docusate sodium and fragrance. Erythromycin and benzoyl peroxide topical gel USP, 3%;5% also contains benzoyl peroxide for topical use. Benzoyl peroxide is an antibacterial and keratolytic agent. Use erythromycin and benzoyl peroxide gel as you were told by the doctor or read the package label. Talk with the doctor. Talk with the doctor. Do not use longer than you have been told by the doctor. How to use Erythromycin-Benzoyl Peroxide Gel. Read the instructions for use that come with this product. This medication is for use only on the skin. Use erythromycin and benzoyl peroxide gel exactly as directed. Do not use more or less of it or use it more often than prescribed by your doctor. Do not use more or less of it or use it more often than prescribed by your doctor. Erythromycin and benzoyl peroxide topical gel usp buy erythromycin animal use I am on endep, (amitriptyline) I have ran out and can not get anymore tonight.