Benzoyl peroxide is a powerful antimicrobial agent destroying both surface and ductal bacterial organisms and yeasts. Its lipophilic properties permit penetration of the pilosebaceous duct and its efficacy is largely against superficial inflammatory lesions. Once applied to the skin, BPO decomposes to release free oxygen radicals, which have potent bactericidal activity in the sebaceous follicles and anti-inflammatory action.[25,26] It also has effects on noninflammatory lesions by reducing follicular hyperkeratosis to some degree. BPO, as with topical retinoids, have no effect on sebum production.
Benzoyl peroxide formulations offer a useful approach in acne patients owing to their highly effective bactericidal effect. They are not associated with antimicrobial resistance and are active against fully sensitive and resistant strains of P. acnes. It is therefore unsurprising that combination preparations of BPO with topical antibiotics have superior activity to monotherapy with a topical antibacterial agent alone against inflammatory and noninflammatory lesions.[29–31] BPO has also been demonstrated to be as effective as first-line oral antibiotic therapy in mild-to-moderate acne. Ozolins et al. demonstrated similar efficacy with 5% BPO when compared with oral tetracycline and minocycline, making BPO a desirable choice in this group in terms of clinical– and cost–effectiveness and in the prevention of the development of resistant strains of P. acnes.
Benzoyl peroxide is currently available in a number of different formulations and concentrations (2.5, 4, 5 and 10%), either alone or in combination with various agents including hydroxychloroquine, imidazole, glycolic acid, zinc lactate and topical antimicrobials. Several lower-concentration preparations are commercially available over the counter. Four randomized control trials (RCTs)have examined different concentrations of BPO[33–36] and no evidence currently supports a dose–response effect. Nevertheless, adverse effects such as irritant dermatitis may prevent the use of high-potency preparations in some patients. This effect can be eased by reducing the frequency of application, and this often subsides as treatment continues. Patients should also be forewarned that BPO can bleach hair and clothing.
A novel combination formulation of 2.5% BPO and 0.1% adapalene has recently been launched in Europe and the USA (Epiduo® [Galderma, Hertfordshire, UK]). A four-arm RCT demonstrated that the combination product was superior (27.5% clear) against monotherapy with 0.1% adapalene alone (15.5% clear) or 2.5% BPO (15.4% clear), which were again superior over the vehicle alone (9.9% clear). This suggests that 2.5% BPO has similar efficacy to 0.1% adapalene in inflammatory acne, with both agents having a similar side effect profile.
Expert Rev Clin Pharmacol. 2010;13(4):563-580. © 2010 Expert Reviews Ltd.
Cite this: Treating Acne Vulgaris: Systemic, Local and Combination Therapy - Medscape - Jul 01, 2010.