Adapalene (Adapalene) is a third-generation synthetic retinoid primarily used in the topical treatment of acne vulgaris. It is a naphthoic acid derivative that possesses potent comedolytic and anti-inflammatory properties. By modulating cellular differentiation and keratinisation, Adapalene prevents the formation of microcomedones (clogged pores) and aids in the clearing of existing acne lesions. It is specifically designed to be more chemically stable and less irritating than traditional retinoids like tretinoin. It is available in multiple formulations, including topical gels, creams, and lotions, allowing for tailored application based on the patient's skin type and the severity of the condition.

Adapalene is a retinoid-like compound that belongs to the naphthoic acid class. It is used to help reduce the formation of acne and manage skin inflammation associated with acne vulgaris.

After topical application, adapalene binds to specific retinoic acid nuclear receptors (RAR-beta and RAR-gamma) but, unlike earlier retinoids, it does not bind to the cytosolic receptor proteins. This selective binding influences the way certain genes are expressed in the skin cells. As a result, the differentiation of follicular epithelial cells is normalised, which prevents the buildup of dead skin cells that plug the pores. By reducing the formation of these microcomedones, Adapalene addresses acne at its earliest stage of development.

In addition to its pore-clearing effects, adapalene possesses significant anti-inflammatory properties. It inhibits the chemotactic and chemokinetic responses of polymorphonuclear leukocytes and suppresses the metabolism of arachidonic acid to inflammatory mediators. This helps lower the redness, swelling, and irritation associated with inflammatory acne lesions.

Adapalene is designed to act locally within the skin. It is highly lipophilic, allowing it to penetrate the hair follicles and sebaceous glands effectively, yet only negligible amounts usually enter the bloodstream when used as directed. This localised action reduces the risk of systemic side effects compared with oral retinoids. However, during the first few weeks of use, patients may experience "retinization," a period where the skin adjusts to the medication and may appear temporarily more irritated or dry.

This medicine should be used under medical supervision or according to the instructions on the label for over-the-counter formulations. The frequency and duration of use depend on the skin's response and the severity of the acne. It is not intended for immediate results, as its effects develop gradually with regular use over 8 to 12 weeks.

Adapalene may be indicated by your doctor for:

Acne Vulgaris

For the topical treatment of mild to moderate acne, including both comedonal (blackheads and whiteheads) and inflammatory acne.

Keratosis Pilaris

Sometimes used off-label to help smooth the "chicken skin" bumps on the arms and legs by exfoliating dead skin cells.

Photoaging

Occasionally utilised under medical guidance to improve the appearance of fine lines and skin texture, though acne remains its primary indication.

Adapalene may provide benefits such as:

• Target the source of acne by preventing the formation of clogged pores (comedolytic action).

• Reduce localised inflammation, leading to a decrease in the redness and swelling of acne pustules and papules.

• Offer a higher degree of photostability compared to older retinoids, meaning it does not break down as easily when exposed to light.

• Provide a better tolerability profile, as it is generally less irritating to the skin than tretinoin.

• Improve skin texture and tone by promoting healthy cell turnover and preventing the accumulation of dead skin.

• Be compatible with other topical acne treatments, such as benzoyl peroxide, when used as part of a comprehensive skincare regimen.

Adapalene may cause side effects in some people, although many tolerate it well when used as prescribed. Side effects are usually localised to the area of application.

Common side effects of Adapalene may include

• Erythema (redness of the skin)

• Scaling or peeling of the skin

• Dryness or stinging sensation

• Pruritus (itching)

• Burning sensation immediately after application

Uncommon side effects of Adapalene may include

• Skin discomfort or "sunburn" feeling

• Acne flare-up (temporary worsening during the first few weeks)

• Contact dermatitis

• Skin discoloration

Serious side effects that may require immediate medical attention include

• Severe skin swelling or crusting

• Persistent and painful burning or irritation

• Signs of a severe allergic reaction, such as rash, swelling of the face/tongue, or severe dizziness

• Eye irritation if the product accidentally comes into contact with the eyes

• Always consult your doctor if you notice any unusual symptoms while taking Adapalene.

• Use adapalene exactly as directed by your doctor or as mentioned on the product label. It is applied to the skin and should be used regularly for acne-prone areas.

• Before applying, gently wash the affected area with a mild, non-irritating cleanser. Pat dry with a soft towel. Avoid harsh soaps, scrubs, or abrasive cleansers, as they may increase skin irritation.

• Apply a thin layer of adapalene over the entire affected area. Do not apply only to individual pimples, as it works by preventing and treating early acne lesions that may not be visible.

• Use clean fingers or an appropriate applicator depending on the formulation (gel, cream, lotion, solution, or pledget).

• If using a pledget (single-use applicator), apply it gently over the affected area and discard it after one use. Do not reuse it.

• Avoid applying excessive amounts. A thin, even layer is sufficient for effectiveness.

• After application, mild skin reactions such as warmth, stinging, dryness, or irritation may occur. These are usually temporary and may reduce with continued use.

• Use consistently as prescribed, as results develop gradually over several weeks. Irregular use may reduce effectiveness.

Adapalene is a retinoid that works by regulating the life cycle of skin cells.

After application, it penetrates the hair follicles and binds to nuclear retinoic acid receptors (RARs). This binding process normalises the differentiation of follicular epithelial cells. In simpler terms, it ensures that skin cells are produced and shed correctly, preventing them from sticking together and clogging the pores. This action stops the formation of the microcomedone, which is the precursor to all acne lesions.

Furthermore, it interferes with inflammatory pathways by inhibiting the oxidative metabolism of arachidonic acid and the movement of inflammatory cells (leukocytes) to the site of the acne. This results in a visible reduction of the redness and swelling that characterise inflammatory acne.

• "Start low and go slow." If your skin is very sensitive, your doctor may suggest applying it every other night initially until your skin adjusts.

• Use a gentle, fragrance-free moisturiser regularly to manage the dryness and peeling that often occurs in the first few weeks.

• Do not use harsh scrubs, astringents, or products containing high amounts of alcohol, as they will increase skin irritation.

• Avoid waxing the areas where you apply Adapalene, as the skin may be more prone to tearing.

• Be patient. It can take 8 to 12 weeks of consistent use to see a significant improvement in your acne.

Store Adapalene at room temperature in a dry place away from direct sunlight and heat.

• Keep the tube tightly closed when not in use.

• Do not freeze the gel or cream.

• Keep all formulations out of the reach of children and pets.

• Do not use after the expiry date printed on the packaging.

• General Diet: There are no known significant interactions between adapalene and specific foods or drinks.

• Vitamin A Supplements: While topical absorption is low, consult your doctor if you are taking high-dose Vitamin A supplements, as they belong to the same chemical family.

• Other Retinoids (SEVERE): Do not use other topical or oral retinoids (like tretinoin or isotretinoin) concurrently unless specifically directed by a dermatologist.

• Photosensitising Medications (CAUTION): Drugs like tetracyclines or thiazides may further increase your sensitivity to sunlight when used with adapalene.

• Abrasive Agents: Products containing sulfur, resorcinol, or salicylic acid should be used with caution to avoid cumulative irritation.

• Eczema/Dermatitis (SEVERE): Adapalene should not be used on skin affected by active eczema or severe dermatitis, as it can cause extreme irritation.

• Sunburn (CAUTION): Do not apply to sunburnt skin. Wait until the skin has fully healed before resuming treatment.

Topical overdose is unlikely to cause systemic problems but will lead to severe redness, peeling, and skin discomfort. If the medication is accidentally swallowed, contact your doctor immediately.

If you miss an application, skip the missed dose and continue with your regular schedule the following evening. Do not apply a double amount to make up for the missed application, as this will only increase skin irritation.