Tretinoin (Retin-A)

Generic name: Tretinoin (tans-retinoic acid , Vitamin A derivative) Trade names: Retin-A, Retin-A Micro, Differin, Avage, Avita, Renova, Atralin Class: Retinoid Topical Formulations: Cream 0.025%, 0.05%, 0.1%; Gel 0.025%, 0.01%; Microsphere gel 0.1%, 0.04% (Retin-A Micro/Pump) Manufacturer: Ortho Dermatologics Uses: acne photodamage fine wrinkles hyperpigmentation tactile roughness of facial skin rejuvenation of aging skin

Description

Tretinoin is a topical retinoid. Retin-A is used in the treatment of acne vulgaris. It normalizes desquamation of the follicular epithelium, promotes drainage of preexisting comedones, and prevents the formation of new comedones.

Tretinoin has proven to be beneficial for skin damaged by the sun and also by natural ageing. Tretinoin helps to reduce fine facial wrinkles, splotchy pigmentation, and rough skin texture. Renova cream 0.02% and 0.05% are the only formulations of tretinoin approved by the FDA for the treatment of visible signs of ageing. Other forms of tretinoin are indicated for acne only.

Topical tretinoin noticeably improves hypertrophic scars, keloids, and acne scars.

When to expect the results?

Improvement in acne is apparent after 2–3 weeks. Optimal results may require more than 6 weeks.

Softening and smoothness of the skin are the first improvements to be noticed. This is achieved due to compaction of the stratum corneum, epidermal thickening, and increased production of hyaluronic acid.

The improvement in wrinkling is a later benefit, seen after 3-4 months of tretinoin application. Tretinoin prevents dermal collagen breakdown and stimulates synthesis of new collagen. It can also safeguard against UV collagen destruction and thus prevent photodamage.

How long to use tretinoin for wrinkles? Tretinoin is safe and effective for long-term (up to 2 years) treatment [1].

The disappearance of mottled hyperpigmentation takes 1 year to become noticeable.

Retin-A vs Adapalene (Differin)

Adapalene 0.1% gel may reduce acne lesion counts more rapidly than tretinoin 0.025% gel. However, after 3 months of application both retinoids bring similar benefits. Adapalene produces less intense skin irritation than tretinoin.

Retin-A vs Tazarotene (Tazorac)

Tazarotene has greater comedolytic activity compared to other topical retinoids. The results of clinical study showed better efficacy of tazarotene in the treatment of acne. The reduction of open comedones at 12 weeks was 65% for tazarotene vs 44% for tretinoin. Tazarotene was also superior in the reduction of non-inflammatory lesions at 12 weeks (55% vs 42% for tretinoin).

Tazarotene cream is slightly better than tretinoin emollient cream (Renova) in improving photodamaged facial skin. Tazarotene provides more rapid improvement in skin appearance, particularly for fine wrinkling and hyperpigmentation.

Retin-A versus Retin-a Micro

While both formulations contain tretinoin (a natural form of vitamin A), the Retin-A Micro offers the advanced microsphere technology to reduce irritation and the appearance of facial shine.

Retin-A Micro uses patented methyl methacrylate/glycol dimethacrylate crosspolymer porous microspheres (Microsponge® System) to enable inclusion of the active ingredient, tretinoin, in an aqueous gel.

What is better: Retin A cream or gel?

In general, tretinoin gel formulation is stronger than cream because the medicine penetrates better when it is in a gel form.

Initial troubles

Acne flare-ups
The treatment of acne with Retin-A can be frustrating in the beginning. Acne can actually flare up initially in the first 2 to 4 weeks, because retinoids tend to reveal what's hiding under the surface. Fortunately, by the end of the second month, a significant improvement with the acne and lessening of irritation is usually noted. You should be aware of these expected sequelae.

Retinoid dermatitis
The benefits of tretinoin are often compromised by temporary initial irritation called retinoid dermatitis. It is a commonly-seen side effect characterized by erythema, peeling, dryness, and pruritus of the skin developing within 3-4 weeks of application. During this period, the retinoid effects are limited to the epidermis. After 3 to 4 weeks, however, dermal effects on collagen, elastin, and extracellular matrix begin to appear. And irritation, erythema, and peeling go off.

Photosensitivity
Use sunscreens for protecting the skin from the harmful effects of UV light, even on cloudy days and winter months. A physical UV block from the sun, such as zinc oxide or titanium dioxide, provides the most protection. Look for one of these key ingredients when selecting a sunscreen.

If prolonged sun exposure is expected, such as a vacation, discontinue use of the retinoid 1 week before the exposure and resume upon return.

Useful tips

It is recommended to apply tretinoin to the entire face on a nightly basis. By applying to the entire face, efficacy can be enhanced, as the active ingredient works where it is placed. Spot treating should be avoided because this can lead to a blotchy appearance of the skin. Application should extend to the hairline and feather down along the jaw line. Mucous membranes, corners of the nose, mouth, and eyes should be avoided. Tretinoin can be applied to upper and lower eyelids, if addressing photodamage.

If bothersome irritation, pruritus, or peeling occurs, you may break 1 to 2 nights off of the tretinoin. Moisturize during the break and then resume the retinoid only with a sunscreen. Do not miss more than 2 days, to minimize the duration of the irritation phase. You may decrease the frequency of application when treating areas such as the eyelids, neck, torso, or extremities to 2 to 3 times a week. Sometimes, decreasing the frequency to every other day or even 3 times a week can be helpful. The strength of tretinoin can also be temporarily decreased.

• 1. Kang S, Bergfeld W, Gottlieb AB, et al. Long-term efficacy and safety of tretinoin emollient cream 0.05% in the treatment of photodamaged facial skin: a two-year, randomized, placebo-controlled trial. Am J Clin Dermatol. 2005;6(4):245-53.