Tretinoin (Topical)

How it works

Tretinoin binds nuclear retinoic acid receptors to normalise follicular keratinocyte differentiation and reduce abnormal cohesion of corneocytes, preventing microcomedone formation and promoting expulsion of existing comedones.

Prescribing in practice

• Topical retinoids are contraindicated in pregnancy and should be avoided in women planning pregnancy, with effective contraception advised during use.
• It commonly causes skin irritation, dryness, erythema and peeling, and increases photosensitivity, so daytime sun protection and avoidance of UV/sunbeds are important.
• An initial apparent worsening of acne can occur before improvement, and concurrent use of harsh or abrasive skin products should be avoided.

Monitoring

No laboratory monitoring is required; review tolerability and acne response, adjusting frequency of application if irritation is excessive.

Counselling the patient

• Apply a thin amount to clean, dry skin at night and use a daytime sunscreen.
• Expect some dryness, redness and peeling initially; reduce frequency if too irritating and allow several weeks for benefit.
• Do not use if pregnant or trying to conceive.

Evidence & guidelines

Topical retinoids such as tretinoin are recommended by NICE as a core component of topical acne treatment, often combined with benzoyl peroxide or a topical antibiotic.