Topical Adapalene for Ongoing Acne Treatment

People with acne who receive oral antibiotic therapy and topical treatment maintained clearer skin using only the topical agents, according to two studies in the May issue of Archives of Dermatology.

Acne is often treated using aggressive combination therapy consisting of oral antibiotics and topical medication (i.e., applied onto the skin). However, acne has become more resistant to antibiotics in recent years, with overall resistance increasing from 20% in 1978 to 62% in 1996, according to James Leyden, MD, et al.

Acne is also a recurring disease and therefore many people with acne undergo long-term therapy. Because of reduced sensitivity to some antibiotics, doctors often recommend that people with acne limit use of antibiotics to three months - consequently, maintenance therapy for acne often consists of topical retinoids, derivatives of vitamin A.

Two studies have recently tested the effectiveness of topical or combined topical and antibiotic (or placebo) maintenance therapy for acne.

First Clinical Trial

In the first study, researchers Diane M Thiboutot, MD, of the Pennsylvania State University College of Medicine and Milton S Hershey Medical Center, and colleagues studied the effectiveness of maintenance therapy using a gel containing adapalene, a retinoid-like compound.

The 253 participants drawn from a previous study had all shown at least moderate improvement in their acne when taking either adapalene gel plus doxycycline (an oral antibiotic; 100 mg) or doxycycline and an unmedicated (placebo) gel.

Participants (aged 12-30 years) were randomly assigned to either adapalene gel or unmedicated (placebo) gel once daily over 16 weeks. Researchers evaluated their acne at the beginning of the study and after four, eight, 12 and 16 weeks.

Participants who received continued treatment with adapalene gel had significantly higher rates of maintaining their previous treatment success, compared with the unmedicated gel group (75% vs. 54%). Moreover, participants received unmedicated gel experienced an increasing number of breakouts.

A survey revealed that significantly more participants receiving adapalene gel were "very satisfied" or "satisfied" with the overall treatment, compared with the other group (75% vs. 58%).

Second Clinical Trial

The second study, by James Leyden, MD, of the Skin Study Center, Broomall, Pennsylvania, and colleagues, examined three different maintenance therapies' effectiveness in participants whose acne had improved on an oral antibiotic plus tazarotene, a topical retinoid gel.

Participants had moderately severe to severe acne and originally had at least a 75% improvement while receiving therapy comprising a gel containing tazarotene (0.1%; nightly) plus the antibiotic minocycline hydrochloride (100-mg capsules; twice daily) for up to 12 weeks.

Participants were randomly assigned to 12 weeks on one of three maintenance therapies: retinoid gel plus placebo capsules; unmedicated gel plus antibiotic capsules; or retinoid gel plus antibiotic capsules. A total of 90 participants (average age, 22 years) completed the maintenance phase of the study.

Results showed that all three regimens were effective in sustaining acne improvement. After 12 weeks of therapy, average reductions in non-inflammatory and inflammatory breakouts were, respectively, 60% and 54% with retinoid gel alone, 52% and 66% with antibiotic capsule alone, and 64% and 66% with retinoid gel plus antibiotic. Overall, through week 24, over 80% of participants in each group had sustained a 50% or greater improvement.

Editorial Comment

In an accompanying editorial, Lee T Zane, MD, MAS, of University of California, San Francisco, writes, "[t]hese studies demonstrate that a substantial proportion of patients can continue to do well for several months following discontinuation of oral antibiotic therapy, likely owing to a class effect of topical retinoids.

"Although admittedly not definitive, these studies offer promising data for the role of retinoids in acne maintenance therapy, and they invite us to give careful consideration to how such therapy should be studied in the future.

"That we are conscious of reducing antibiotic overuse and actively exploring therapeutic options to long-term oral antibiotic therapy is truly a step in the right direction."

Sources: Adapalene Gel, 0.1%, as Maintenance Therapy for Acne Vulgaris: A Randomized, Controlled, Investigator-Blind Follow-up of a Recent Combination Study. Diane M Thiboutot, MD, et al, Archives of Dermatology, volume 142, pages 597-602, 2006. Comparison of Tazarotene and Minocycline Maintenance Therapies in Acne Vulgaris: A Multicenter, Double-blind, Randomized, Parallel-Group Study. James Leyden, MD, et al. Archives of Dermatology, volume 142, pages 605-612, 2006. Acne Maintenance Therapy: Expanding the Role of Topical Retinoids? Lee T. Zane, MD, MAS, Archives of Dermatology, volume 142, pages 638-640, 2006.

Latest Pharma Industry News...

Pharma Industry News Archive

More News Resources

Daily MedNews
Pharma Industry News
New Drug Applications
New Drug Approvals
Clinical Trial Results
Generic Drug Approvals
Monthly Update Archive