Acne Treatment with Topical Retinoids Retin-A
Topical retinoids are the foundation for the treatment of acne. They are effective for comedonal and inflammatory acne.
Mechanism of action
Retinoids normalize keratinization. They increase the turnover of follicular epithelial cells, corneocytes are shed at an accelerated rate and comedones are extruded. New comedone formation is inhibited.
The choice of vehicle is important. Creams are used for dry sensitive skin, gels are for patients with oily skin. Tretinoin was the first retinoid. It may cause irritation and improvement may not occur for 1-3 months. Tretinoin is not stable in sunlight.
Tretinoin (Retin-A and generics)
Cream: 0.025%, 0.05%, 0.1%
Gel: 0.01%, 0.025%
Tretinoin in other vehicles
Microsphere vehicle (Retin-A Micro): 0.04% gel, 0.1% gel
Adapalene is a derivative of tretinoin. It is stable in sunlight and resistant to oxidation by benzoyl peroxide. Adapalene has a low irritation potential and no phototoxicity.
Third-generation topical retinoids
Adapalene (Differin): 0.1% gel, 0.1% solution, 0.1% pledgets, 0.1% cream
Tazarotene is a synthetic retinoid that is effective for acne and psoriasis. Tretinoin and adapalene are category C drugs, and tazarotene is a Category X drug. This difference in categorization by the FDA is based on the use of tazarotene in the treatment of psoriasis
Third-generation topical retinoids
Tazarotene (Tazorac): 0.1% cream, 0.1% gel where medication is used over a wide area.
The newer topical retinoids have an antiinflammatory effect and are first-line treatment for both comedonal and inflammatory acne. Topical retinoids are used for maintenance therapy to prevent the formation of new microcomedones. Topical retinoids are often used in combination therapy, especially with benzoyl peroxide and topical and/or oral antibiotics.
Patient instruction of use of topical retinoids
Proper use and application is the key to success and avoiding irritation. It is not necessary to produce irritation to obtain efficacy. Patients who are irritated will be noncompliant. Wash the face with a mild cleanser. A Soapless cleanser such as Cetaphil can be used for patients with very sensitive skin. Avoid wash cloths or abrasive cleansers. Wait for 20 minutes so that the skin becomes dry.
Application of medication to wet skin enhances penetration and irritation. Apply just enough medication to cover the skin.
Acne may be worse in the first few weeks as microcomedones and comedones are extruded.
Consider starting with every other day application until daily application can be tolerated. Another technique is to apply the retinoid in a “short-contact” manner. Apply medication for 30 seconds to 5 minutes then wash off the drug. This can be done once or twice each day to help the skin to adapt.
- Wash face gently with a mild cleanser
- Wait 20 minutes after washing before application
- Apply a very thin layer of medication.
- Use noncomedogenic moisturizers to control irritation
- Avoid excessive sun exposure
- Apply a sunscreen daily
- Protect the face from cold and wind
Several studies have compared these agents.
Tazarotene gel 0.1 is more effective than tretinoin gel 0.025 and the microsphere gel. The reduction of open comedones at 12 weeks was 65% for tazarotene vs 44% for tretinoin.
Adapalene gel 0.1% is as effective as tretinoin gel microsphere 0.1% after 12 weeks of treatment, but tretinoin gel achieved a greater reduction in the number of comedones at week 4.
Alternate-day applications of tazarotene 0.1% gel and daily applications of adapalene 0.1% gel give similar results at 15 weeks.
The response to tazarotene treatment was greater during the first 3-6 weeks of treatment.
Tazarotene plus clindamycin lotion is more effective than either agent used alone. Tazarotene in combination with benzoyl peroxide or an erythromycin/benzoyl peroxide gel is as effective as tazarotene used as monotherapy.