外用 A 酸 (Tretinoin / Retin-A) Tretinoin (Topical)

RETIN-A (tretinoin) is indicated for topical application in the treatment of acne vulgaris. RENOVA (tretinoin cream) 0.05% is indicated as an adjunctive agent for use in the mitigation (palliation) of fine wrinkles, mottled hyperpigmentation, and tactile roughness of facial skin in patients who use comprehensive skin care and sunlight avoidance programs. RENOVA DOES NOT ELIMINATE WRINKLES, REPA…

For topically applied retinoids (adapalene, alitretinoin, isotretinoin, tazarotene and tretinoin), systemic absorption is negligible, and unlikely to result in psychiatric disorders. ... topical retinoids must also not be used during pregnancy, and by women planning to have a baby.

Tretinoin and adapalene are topical retinoids used to treat acne. They're available in a gel or cream and are usually applied once a day before you go to bed. Apply to all the parts of your face affected by acne 20 minutes after washing your face. Topical retinoids work by removing dead skin cells from the surface of the skin (exfoliating), which helps prevent them building up within hair folli…

外用A酸藥膏，僅新上市或濃度較高的製劑屬於處方藥，其他多數外用A酸，例如濃度不超過0.1%之Tretinoin，即為指示藥品，民眾可在諮詢藥師或醫師後，自行於藥局購買。衛生福利部食品藥物管理署建議，若是嚴重或大面積痤瘡，應尋求專科醫師診治；而輕度及小面積的痘痘，則可至藥局向藥師諮詢，再購買外用A酸指示藥品。

It is on the World Health Organization's List of Essential Medicines. [...] the compound received US Food and Drug Administration (FDA) approval for acne in 1971. [...] Use during pregnancy is contraindicated due to the risk of birth defects. [...] Tretinoin activates three members of the retinoic acid nuclear receptors (RARα, RARβ, and RARγ) which may act to modify gene expression, subsequent …

成分為Tretinoin，常見商品名稱包含: 愛膚露 (Airol)、愛潔膚 (Airful)、蕾婷 (Retin-A)、愛克凝膠 (Acned gel)等。口服A酸屬於處方藥，須由醫師診治、開立處方才可取用。至於外用A酸藥膏，僅新上市或濃度較高的製劑屬於處方藥，其他多數外用A酸，例如濃度不超過0.1%之Tretinoin，即為指示藥品，民眾可在諮詢藥師或醫師後，自行於藥局購買。屈臣氏、康是美：依法不可販售，架上通常是『類 A 醇 (Retinol)』保養品，而非藥膏。

外用A酸在台灣皆屬於『處方藥』，因此需經皮膚科醫師診斷後開立處方箋才能購買。第一代A酸（包括愛潔膚、蕾婷、欣婷等常見品牌）納入健保給付範圍，或可自費購買（約$100-200）。

第一代的 A 酸 Tretinoin 在局部外用的時候，會改變皮膚上皮細胞的生長和分化，增進毛囊上皮的代謝……第一代 A 酸效果不錯，但皮膚的刺激性、光敏感性強，可能會造成皮膚有灼熱感、紅斑、水腫或是起疹子。外用A酸在剛開始擦的時候，洗完臉都會有微微的刺痛感，可以減少塗抹的量和區域，繼續持續塗抹後，皮膚就會習慣了。