Tazorac
Tazorac
Generic Name
Tazorac
Mechanism
* Selective RAR agonist – preferentially activates retinoic acid receptors‑α (RAR‑α) and RAR‑γ in keratinocytes.
* Modulates keratinocyte proliferation – normalizes hyper‑proliferation and enhances programmed cell death.
* Promotes epidermal differentiation – restores the stratum corneum and reduces scaling.
* Anti‑inflammatory effect – down‑regulates pro‑inflammatory cytokines in psoriasis lesions.
The selective receptor activity results in potent, yet localized, dermatologic action with minimal systemic exposure.
Pharmacokinetics
| Parameter | Detail |
| *Absorption* | Topically applied tazarotene penetrates skin layers (~80 % to viable epidermis). Systemic absorption ≤ 0.5 % of applied dose. |
| *Distribution* | Minimal systemic distribution; plasma concentrations < 20 ng/L. |
| *Metabolism* | Primarily hepatic CYP3A4 → hydroxylated metabolites; elimination largely fecal. |
| *Half‑life* | Local skin retention: ~4–6 h; systemic half‑life 1–2 h. |
| *Drug–Drug Interaction* | Co‑administer with other potent CYP3A4 inhibitors may modestly increase plasma levels; topical safety not compromised. |
Indications
* Plaque‑type psoriasis – 0.1 % ointment/cream or 0.05 % gel, once daily (usually nightly).
* Acne vulgaris – 0.05 % gel or cream, once daily (evening).
* Often used in combination therapy:
* Psoriasis: tazarotene + topical clindamycin or corticosteroid.
* Acne: tazarotene + benzoyl peroxide or topical antibiotics.
Contraindications
* Contraindicated in pregnancy (Category X) and during lactation; avoid use in pregnant or nursing patients.
* Known hypersensitivity to tazarotene, other retinoids, or excipients.
* Worn contact lenses – avoid contact with facial areas; remove lenses before use.
* Extreme photodermatitis – avoid in patients with photosensitive dermatoses unless closely monitored.
* Use caution in patients with a history of skin cancer or severe keloid formation.
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Dosing
1. Psoriasis
* 0.1 % ointment/cream: Apply a thin layer to affected skin once nightly.
* Dosing schedule: Start with 1–2 weeks of intermittent use (e.g., 3 days on, 4 days off) to allow skin tolerance, then proceed with continuous use.
2. Acne
* 0.05 % gel/cream: Apply a pea‑size amount *once nightly* to clean, dry skin.
3. General Tips
* Wash hands after application.
* Avoid areas around the eyes, lips, and mucous membranes.
* Combines with topical sunscreens (SPF 30+) daily to mitigate photosensitivity.
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Adverse Effects
| Adverse Effect | Frequency | Notes |
| Burning, sting, erythema | Common (30–50 %) | Often transient; diminishes with continued use. |
| Dryness, scaling, flaking | Common | Treat with emollients. |
| Photosensitivity | Moderate | Sun avoidance, sunscreen essential. |
| Allergic dermatitis | Rare | Discontinue, consider alternate therapy. |
| Increased sebaceous gland activity (rare) | Rare | Reduce frequency of application initially. |
| Serious | ||
| Teratogenic effects | Pregnancy exposure | Contraindicated in pregnant/nursing women. |
| Severe sunburn/photodamage | Rare | Monitor in high‑UV regions. |
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Monitoring
| Parameter | Frequency | Rationale |
| Skin tolerance (erythema, burning) | Baseline, 1‑week, 4‑week, then as needed | Adjust frequency or concentration. |
| Photodamage signs | Monthly (high‑UV users) | Ensure sun‑safety compliance. |
| General health in long‑term use | Annually | Verify no systemic signs of retinoid toxicity. |
| Pregnancy status | Every visit if female of childbearing age | Tazarotene is teratogenic; require contraception counseling. |
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Clinical Pearls
* Exfoliation Timing – Apply tazarotene in the evening; use a light sunscreen in the morning to reduce photosensitivity and maintain efficacy.
* Combination Edge – Adding a mild topical steroid can shorten onset of action for psoriasis, but a taper‑off strategy is recommended to avoid steroid‑resistant activity.
* Acne “Stagger” – For sensitive skin, start with every‑other‑night dosing for the first 2‑3 weeks; this improves adherence and reduces irritation.
* Storage – Keep in a cool, dry place; protect from heat to maintain integrity of the retinoid matrix.
* Pregnancy Counseling – Immediately cease therapy and counsel on effective contraception. Offer alternative non‑retinoid regimens if needed.
* CYP3A4 Inhibitors – Though systemic levels are negligible, avoid using tazarotene with strong topical CYP3A4 inhibitors to preclude unpredictable absorption.
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• Key References
1. Centers for Disease Control and Prevention. *Psoriasis Management: Evidence‑Based Guidance.*
2. FDA Label — *Tazarotene* (Tazorac).
3. Korman, N. (2019). *The Dermatology Pharmacology Review.* Edinburgh : Routledge.