Pharm

Tretinoin

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Tretinoin, Retin A, Retin-A

  • Preparations
  1. Standard preparations
    1. Retin A Cream 0.025% 0.05% 0.1%
      1. Cream 0.025% is as effective and less irritating than .05-.1%
      2. Lower concentration simply takes a little longer for improvement
    2. Retin A Gel 0.01%, 0.025% 0.005%
    3. Retin A Lotion 0.05% (Avoid - VERY irritating)
      1. Altreno (0.05% lotion)
        1. Released in 2019 as "hydrating" with collagen and hyaluronic acid
        2. Contains fish proteins (risk of Allergic Reaction)
        3. Expensive ($120/45 grams) and unlikely to be covered by insurance
        4. No evidence of benefit over generic options (e.g. Tretinoin, Adapalene)
        5. (2019) Presc Lett 26(3): 16
  2. Less irritating agents
    1. Retin-A Micro (Tretinoin gel microsphere)
    2. Avita (Tretinoin 0.025%)
  • Dosing
  • Directions for use
  1. Apply one dot (split-pea size) per one triangle of face (forehead, right malar, left malar)
  2. Initially apply only for a few hours
    1. Slowly increase length of treatment
    2. Titrate up to overnight application as tolerated
  3. Often used with Topical Antibiotics (e.g. Clindamycin)
    1. Clindamycin reduces irritating effect of Tretinoin
    2. Example schedule
      1. Morning: Clindamycin applied
      2. Evening: Tretinoin applied
  • Adverse Effects
  1. Scaling
  2. Skin dryness
  3. Local irritation, erythema or inflammation
    1. Creams irritate less than lotions
    2. Irritation can be reduced by adding Hydrocortisone
      1. 1 part Retin A 0.025%, 1 part Hydrocortisone 1%
  4. Local skin sensation of burning or stinging
  5. Local Pruritus
  6. Photosensitivity
  7. Initially exacerbates inflammatory lesions
  • Safety
  1. Pregnancy Category C
  • Efficacy
  1. Most potent Comedolytic
  2. Good results in 75% of patients in 3 months
  • Mechanism
  1. Comedolytic
  2. Lowers cohesiveness of follicular epithelial cells
    1. Decreases micro-comedo formation
  3. Increases follicular cell turnover
    1. Results in extrusion of existing comedones