ROCKVILLE, Md. The Food and Drug Administration (FDA) recently approved a new topical prescription medication for the treatment of acne.
Differin Gel (adapalene) is a new synthetic retinoid analogue. Officials at Galderma Laboratories, which distributes adapalene gel, said the product will be available in the third-quarter of this year. Adapalene gel is a white, odorless gel that quickly penetrates deeply into hair follicles where it can exert its anti-inflammatory and comedolytic effects. The oil-free and alcohol-free gel is formulated for the skin of someone with acne-prone skin.
Acne affects 17 million Americans, most between the ages of 12 and 24 years. Although the acne of most patients clears by their early 20s, 11% of adults from 25 to 44 still suffer from some form of the disease. Adult acne is a common disorder among women.
Acne is caused by the obstruction of the hair follicle by sebum, the oily substance secreted by the sebaceous glands in the skin. When a plug of sebum becomes trapped in the follicle, bacteria multiply and the follicle becomes inflamed, leading to the development of pimples and comedomes. The face, back, chest and shoulders can be affected.
Factors that influence the progression of acne include:
Contrary to popular belief, food is not a primary cause of acne.
In controlled clinical trials, adapalene effectively reduced the number and severity of acne lesions after 12 weeks of therapy and has demonstrated greater effectiveness than the highest strength of topical tretinoin gel (0.025% gel). Patients using adapalene experienced significantly less skin dryness and irritation. Stinging, burning, peeling and skin redness associated with retinoid therapy have been a barrier to patient compliance with tretinoin acne medication.
In one trial, 323 patients were randomized to receive either adapalene or tretinoin. The patients applied the medications to the entire face every day for 12 weeks. Thirty-five patients did not complete the study. Follow-up occurred during weeks two, four, eight and 12. Starting at weeks two and four, the adapalene group produced fewer lesions than the tretinoin gel (37% vs. 49% for total lesions).
"Retinoid therapy has been recognized for more than 20 years to be excellent acne therapy, but the side effects have always been a double-edged sword limiting its use in many patients," said James Leyden, MD, professor of dermatology, University of Pennsylvania and a clinical investigator for adapalene. "However, the benefit is that Differin is quite effective, and tolerance is very good, even continuing to improve with treatment."
There are some adverse effects: erythema, scaling, dryness, pruritus and burning will occur in 10% to 40% of patients. Pruritus or burning immediately after application also occurs in about 20% of patients. Skin irritation, burning/stinging, erythema, sunburn and acne flares were also seen in 1% or fewer patients.
Adapalene is the first new retinoid for the treatment of acne since oral isotretinoin (Accutane, Roche) was introduced in 1982, and the first new topical retinoid since tretinoin (Retin-A, Ortho) in 1972.
For more information, see:
- Shalita A, Weiss JS, Chalker DK, et al. A comparison of the efficacy and safety of adapalene gel 0.1% and tretinoin gel 0.025% in the treatment of acne vulgaris: a multicenter trial. J Am Acad Dermatol 1996;34:482-5.
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