Author:
James Q. Del Rosso, DO, FAOCD, Dermatology Residency Director, Valley Hospital Medical Center, Las Vegas, Nevada

Introduction

Acne vulgaris and rosacea are two of the most commonly encountered skin disorders in ambulatory dermatology practice. Involvement of the face and the chronicity of these conditions produce significant personal stress and frustration for many patients who hope for control of unpredictable and bothersome breakouts. Both these disorders were discussed in symposia at the South Beach Symposium at the Loews Hotel on Friday, February 15, 2007. ,

Advancement in Acne Therapy: New Retinoids

Dr. James Del Rosso, Valley Hospital Medical Center Las Vegas, NV, discussed the use of topical retinoids in the management of acne vulgaris.¹ "It is important for clinicians to recognize that use of a topical retinoid is a vital component of both initial treatment and maintenance therapy for acne vulgaris. In addition to their ability to reduce non-inflammatory lesions (comedos), it is well-documented that topical retinoids also substantially reduce inflammatory acne lesions".

Dr. Del Rosso discussed results from several clinical trials completed with all 3 topical retinoids – tretinoin, adapalene, and tazarotene, including initial monotherapy pivotal trials and studies involving combination therapy with a benzoyl peroxide (BPO)-containing formulation.^2,3,4 The availability of newer vehicles that reduce the risk and intensity of "retinoid dermatitis", such as the microsphere gel with tretinoin, has allowed for effective combination topical treatment of acne vulgaris from the outset as more patients are able to tolerate combination topical treatment with few or no signs of skin irritation. Dr. Del Rosso commented on clinical studies of BPO-clindamycin gel (tube formulation) used in combination with either, tazarotene cream 0.1%, tretinoin microsphere gel 0.04% or 0.1%, or adapalene gel 0.1%. In all 3 studies, the BPO-clindamycin gel and the topical retinoid were applied in the morning and at bedtime, respectively. The combination topical approach of a retinoid used along with BPO-clindamycin from the outset of therapy exhibited inflammatory and non-inflammatory lesion reductions after 12 weeks of at least 60% and 55%, respectively, with all 3 retinoids. In one trial, the study arm using both BPO-clindamycin and tazarotene demonstrated a marked reduction in non-inflammatory lesions at week 4 (34%) and week 8 (64%).⁴ Tolerability results were very favorable in all 3 trials. A case report series of BPO microsphere cream applied once daily in the morning used in combination with tretinoin microsphere gel 0.04% once daily at night also proved to exhibit effective results with no reports of skin irritation.

The use of appropriate skin care is important in the treatment of acne vulgaris, serving to improve epidermal barrier function, reduce potential for skin irritation associated with topical medications, and augment the ability of acne medications to reduce acne lesions. A prepackaged kit is available which contains tretinoin cream, a gentle cleanser and a moisturizer, thus providing an additional "convenience value".⁵ A recent study evaluating the use of tazarotene 0.1% cream and a ceramide-based moisturizer cream in subjects with acne vulgaris demonstrated that application of the moisturizer first did not interfere with therapeutic results.

Newer formulations containing topical retinoids were discussed by Dr. Del Rosso. Adapalene gel 0.3% was shown to produce two-thirds of its therapeutic effect within the first 4 weeks of therapy, and in a long-term monotherapy study continued to progressively reduce both inflammatory and non-inflammatory lesions over 12 months.^6,7 A water-based gel containing tretinoin 0.05% applied once daily proved to be comparable to, but not non-inferior to, tretinoin microsphere gel 0.1% based on statistical analysis of efficacy data from a 12-week, controlled, non-inferiority study.⁸ The aqueous-based vehicle of the tretinoin gel 0.05% contains multiple humectants designed to minimize transepidermal water loss and reduce cutaneous irritation, and proved to be less irritating to skin than tretinoin microsphere gel 0.1% in a controlled, comparative study.

Dr. Del Rosso also reviewed a combination aqueous polymer gel which is applied once daily and contains clindamycin phosphate 1.2% and tretinoin 0.025% (clinda/tretinoin).⁹ In this formulation, tretinoin is present in both solubilized and crystalline forms. The crystalline form of tretinoin allows for slow release of active drug with a very low potential for skin irritation, and tretinoin particle size is tightly controlled, thus providing optimal penetration. The superior efficacy of clinda/tretinoin gel as compared to the individual active components was established in pivotal trials in subjects with mild, moderate, and severe acne vulgaris.