Tretinoin
(Retinoic acid, Vitamin A acid)
Tretinoin (Retin-A)
Retinoic acid (Retin-A)
Vitamin A acid (Retin-A)
Tretinoin
( TRET-ih-noyn)
Pregnancy Category: C (Topical products), D (Oral products) Avita Renova Retin-A Retin-A Micro Retisol-A StieVA-A StieVA-A Forte Vesanoid Vitinoin (Rx)

Classification: Antiacne drug

Action/Kinetics: Topical tretinoin is believed to decrease microcomedone formation by decreasing the cohesiveness of follicular epithelial cells. Also believed to increase mitotic activity and increase turnover of follicular epithelial cells as well as decrease keratin synthesis. Some systemic absorption occurs (approximately 5% is recovered in the urine).
The mechanism of action for PO use in acute promyelocytic leukemia (APL) is not known. Absorption is enhanced when the drug is taken with food. Time to peak levels: 1-2 hr. Is over 95% bound to plasma proteins (mainly to albumin). Terminal elimination t 1/2: 0.5-2 hr in APL clients. Metabolized by the liver, with about two-thirds excreted in the urine and one-third in the feces.

Uses: Dermatologic: A vita, R etin-A: Acne vulgaris. Retin-A and Renova: As an adjunct to comprehensive skin care and sun avoidance to treat fine wrinkles, mottled hyperpigmentation, and roughness of facial skin caused by age and the sun. For those individuals who do not achieve palliation using comprehensive skin care and sun avoidance programs alone. Investigational ( Retin-A): Treat various forms of skin cancer. Dermatologic conditions including lamellar ichthyosis, mollusca contagiosa, verrucae plantaris, verrucae planae juveniles, ichthyosis vulgaris, bullous congenital ichthyosiform, and pityriasis rubra pilaris. To enhance the percutaneous absorption of topical minoxidil.
Oral: To induce remission in APL. After induction therapy with tretinoin, clients should be given a standard consolidation or maintenance chemotherapy regimen for APL, unless contraindicated.

Contraindications: Eczema, sunburn. Use if inherently sensitive to sunlight or if taking other drugs that increase sensitivity to sunlight. Use of Renova if client is also taking drugs known to be photosensitizers (e.g., fluoroquinolones, phenothiazines, sulfonamides, tetracyclines, thiazides). Those allergic to parabens (preservative in the gelatin capsules). Use of PO form during lactation. Use around the eyes, mouth, angles of the nose, and mucous membranes.

Special Concerns: Use with caution during lactation. Safety and effectiveness have not been determined in children. Excessive sunlight and weather extremes (e.g., wind and cold) may be irritating. Use Avita and Renova with caution with concomitant topical medications, medicated or abrasive soaps, shampoos, cleansers, cosmetics with a strong drying effect, permanent wave solutions, electrolysis, hair depilatories or waxes, and products with high concentrations of alcohol, astringents, spices, or lime. Safety and efficacy of Renova have not been determined in children less than 18 years of age, in individuals over the age of 50 years, or in individuals with moderately or heavily pigmented skin. Use of the PO form has resulted in retonic acid-APL syndrome, especially during the first month of treatment. The safety and efficacy of oral tretinoin at doses less than 45 mg/m ²/day have not been evaluated in children.

Side Effects: Following topical use. Dermatologic: Red, edematous, crusted, or blistered skin; hyperpigmentation or hypopigmentation, increased susceptibility to sunlight, erythema, pruritus, burning, dryness. Excessive application will cause redness, peeling, or discomfort with no increase in results.
Following oral use. Retinoic acid-APL syndrome: Fever, dyspnea, weight gain, radiographic pulmonary infiltrate, pleural or pericardial effusions. Occasional impaired myocardial contractility and episodic hypotension; possibility of concomitant leukocytosis. Progressive hypoxemia with possible fatal outcome. Respiratory symptoms, including upper respiratory tract disorders, respiratory insufficiency, pneumonia, rales, expiratory wheezing, lower respiratory tract disorders, bronchial asthma, pulmonary or larynx edema unspecified pulmonary disease. Pseudotumor cerebri (especially in children): Papilledema, headache, N&V;, visual disturbances. Typical retinoid toxicity (similar to ingestion of high doses of vitamin A): Headache, fever, dryness of skin and mucous membranes, bone pain, N&V;, rash, mucositis, pruritus, increased sweating, visual disturbances, ocular disorders, alopecia, skin changes, changed visual acuity, bone inflammation, visual field defects. Body as a whole: Malaise, shivering, hemorrhage, DIC infections, peripheral edema, pain, chest discomfort, edema, weight increase, anorexia, weight decrease, myalgia, flank pain, cellulitis, facial edema, fluid imbalance, pallor, lymph disorders, acidosis, hypothermia, ascites. GI: GI hemorrhage abdominal pain, various GI disorders, diarrhea, constipation, dyspepsia, abdominal distension, hepatosplenomegaly, hepatitis, ulcer, unspecified liver disorders. CV: Arrhythmias, flushing, hypotension, hypertension, phlebitis, cardiac failure, cardiac arrest, stroke MI, enlarged heart, heart murmur, ischemia, myocarditis, pericarditis, pulmonary hypertension, secondary cardiomyopathy. CNS: Dizziness, paresthesias, anxiety, insomnia, depression, confusion, cerebral hemorrhage, intracranial hypertension agitation, hallucinations, abnormal gait, agnosia, aphasia, asterixis, cerebellar edema, cerebellar disorders, convulsions, coma CNS depression, dysarthria, encephalopathy, facial paralysis, hemiplegia, hyporeflexia, hypotaxia, no light reflex, neurologic reaction, spinal cord disorder, tremor, leg weakness, unconsciousness, dementia, forgetfulness, somnolence, slow speech. GU: Renal insufficiency, dysuria, acute renal failure, micturition frequency, renal tubular necrosis, enlarged prostate. Otic: Earache, feeling of fullness in the ears, hearing loss, unspecified auricular disorders, irreversible hearing loss. Other: Erythema nodosum, basophilia, hyperhistaminemia, Sweet's syndrome, organomegaly, hypercalcemia, pancreatitis, myositis.

Laboratory Test Alterations: Elevated LFTs following use of PO product.

Drug Interactions: Concomitant use with sulfur, resorcinol, benzoyl peroxide, or salicylic acid may cause significant skin irritation.

How Supplied: Cream: 0.025%, 0.05%, 0.1%; Gel: 0.01%, 0.025%, 0.1%; Liquid: 0.05%; Capsules: 10 mg

Dosage
?Cream, Gel, or Liquid Acne vulgaris.
Apply lightly over the affected areas once daily at bedtime. Beneficial effects many not be seen for 2-6 weeks.
?Cream, 0.025%, 0.05%, 0.1% Palliation for skin conditions.
Apply a pea-sized amount once daily at bedtime, using only enough to lightly cover the entire affected area. Up to 6 months of therapy may be needed before effects are seen.
?Capsules APL.
Adults: 45 mg/m ²/day given as two evenly divided doses. Given until complete remission is obtained. Discontinue 30 days after achieving complete remission or after 90 days of treatment, whichever comes first.