Benzoyl peroxide has been, for quite some time now, one of the most important and well-known drug formulations available for topical acne treatment. It has very useful properties, such as strong anti microbial action and slight anti-inflammatory and anticomedogenic effects making it a very effective anti-acne agent. It is an excellent first choice medication and the initial response to treatment is obtained in as early as five days.

Treatment with benzoyl peroxide alone

In fact, treatment with benzoyl peroxide alone significantly improves inflammatory acne. Side effects encountered are common irritant dermatitis with erythema, scaling and itching. These side effects can, however, be avoided or lessened by less frequent application of benzoyl peroxide. The incidence of true contact sensitivity is low. Very rarely, it produces photosensitivity. It is known that water-based benzoyl peroxide preparations with concentrations between 2.5% to 5% are found to cause significantly less skin irritation than preparations based on alcohol, with no loss in efficacy. A disadvantage, rather than side effect, that a user needs to be aware of is that benzoyl peroxide can bleach clothing and bedding.

A study was conducted recently to compare the effectiveness of 2.5%, 5% and 10% formulations of gel benzoyl peroxide. It was found that the 2.5% formulation was as effective and less drying as the two other formulations in reducing inflammatory lesions and significantly reduced acne after two weeks of topical application. Local side effects were less frequent with the 2.5% and 5% formulations than with the 10% gel.

Benzoyl peroxide in combination therapy

The use of benzoyl peroxide in combination therapy started with the dramatic increase of bacterial resistance to antibiotics among patients with acne. Treatment with antibiotics rapidly induces bacterial resistance and decreases the efficacy of these drugs. Benzoyl peroxide protects against such developments. Currently, the use of combination therapy, such as the addition of benzoyl peroxide to a topical drug to reduce bacterial resistance, has become commonplace.

Combination therapy of benzoyl peroxide and topical antibiotics has been shown to be more effective and better tolerated than with benzoyl peroxide alone. This might be correlated to leukocyte antioxidant enzyme activity. In one study it was seen that after 4 weeks of twice daily treatment with benzoyl peroxide 5% gel alone, no changes were observed, whereas the combination of erythromycin 3% and benzoyl peroxide 5% led to reduced antioxidant enzyme activities in the leukocytes of acne spots.

According to most recent reports, antibiotic resistance is becoming an increasing problem. The resistance is found more often in the case of erythromycin and clindamycin as compared with tetracyclines, although resistance is seen against all of the antibiotics in general use for acne. The resistance strains that could be isolated from physicians and casual contacts of acne patients treated with antibiotics indicated the urgent need to develop ways and means to combat the spread of and reduce antibiotic resistance. It is therefore important that benzoyl peroxide, which both reduces the still existing antibiotic resistant populations and decreases the emergence of new resistant populations, should be used where possible.

In combination therapy, despite its high effectiveness as an anticomedogenic, antimicrobial and antibacterial agent, benzoyl peroxide is limited by its side effects of dryness and irritation mentioned above. Combination therapy with once daily tretinoin 0.1% microsphere gel and benzoyl peroxide 6% cleanser was shown to be more effective in reducing inflammatory but not non-inflammatory lesions in comparison with tretinoin 0.1% microsphere alone at 12 weeks, without an accompanying increase in local skin irritation.

Recently, new premixed formulations of benzoyl peroxide and topical antibiotics have been introduced. These newer formulations are stable at room temperature and more convenient for patients than older preparations, which required refrigeration. The premixed combination products include erythromycin 3% and benzoyl peroxide 5% or clindamycin 1% and benzoyl peroxide 5%. Clindamycin 1% with benzoyl peroxide 5% topical products used once daily have been shown to be effective in reducing inflammatory and noninflammatory lesions by 53% and 25% respectively for patients with moderate or moderately severe acne after 11 weeks of treatment. Patients generally tolerated these preparations well.

Overall then, benzoyl peroxide is an acne treatment that is well worth considering either on its own or in combination with other treatments.