Tretinoin

Selected capsules induce remission in adults and children ≥1 year with acute promyelocytic leukemia characterized by t(15;17) translocation or PML/RARα fusion, who are refractory to or have relapsed from anthracycline chemotherapy, or for whom anthracycline chemotherapy is contraindicated. Treatment may begin on morphologic suspicion while confirmation is pending; discontinue if the defining genetic finding is absent. This is the selected regulatory indication, not a complete contemporary APL combination protocol.

Retin-A cream/gel and Retin-A Micro treat acne; selected labels establish pediatric use at ≥12 years. Altreno lotion treats acne at ≥9 years. Renova 0.02% is an adjunct to comprehensive skin care and sunlight avoidance for palliation of fine facial wrinkles, with use below 18 unestablished. It does not eliminate wrinkles, repair sun damage, reverse photoaging, or treat/prevent skin cancer or actinic keratoses; safety/effectiveness beyond 52 weeks of daily use is unestablished.

Avoid eyes, lips and mucosa and do not apply to sunburned skin. Temporarily stop or adjust treatment with the prescriber when irritation warrants; Micro may resume after reaction resolves, but efficacy of reduced frequency is not established. Acne benefit takes weeks; initial inflammatory worsening can occur. Renova benefit may take up to 6 months and may diminish after stopping. No oral-to-dermal dose conversion or routine renal/hepatic percentage adjustment is supported.

Oral capsules: hypersensitivity to tretinoin, components or other retinoids. Retin-A and Renova: sensitivity to components; discontinue for hypersensitivity. Current Micro and Altreno formal contraindication sections list none. Oral fetal toxicity remains a boxed warning even though pregnancy is not listed in selected section 4. Renova dosing instructions separately say do not use with pregnancy/attempted pregnancy/high pregnancy risk, sunburn, eczema/chronic facial skin conditions, inherent sunlight sensitivity or photosensitizing drugs; these instructions are not all its formal contraindication heading.

Selected oral label boxes embryo-fetal toxicity and differentiation syndrome. The selected dermal labels have no boxed warning; this does not establish pregnancy safety or justify copying oral pregnancy-prevention rules onto every cream.

Oral APL trials commonly reported headache, fever, skin/mucosal dryness, bone pain, malaise, dyspnea, hemorrhage, infection, nausea/vomiting, rash, edema and leukocytosis. Dermal reactions predominantly involve local dryness, pain, redness, peeling and irritation, with pigment changes reported. Rates from different products/trials are not directly comparable. Oral overdose can cause hypervitaminosis-A symptoms and requires specialist hematology care; no specific treatment is supplied. Excess topical application worsens irritation without improved efficacy; accidental ingestion needs Poison Help/medical assessment.

• Avoid strong CYP3A inhibitors if possible; if unavoidable, monitor frequently for adverse reactions. Moderate CYP3A inhibitors also require frequent monitoring. Avoid strong CYP3A inducers, which can lower exposure.
• Avoid vitamin A supplements and products known to cause intracranial hypertension, including tetracyclines.
• Avoid antifibrinolytics such as tranexamic acid, aminocaproic acid and aprotinin because of potentially fatal thrombotic complications.

Medicated/abrasive cleansers, alcohol-rich or drying products and other irritating topical treatments can intensify irritation. Micro specifically cautions about OTC benzoyl peroxide, sulfur, resorcinol and salicylic acid. Follow the prescriber’s combination plan rather than assume every combination is prohibited. Renova should not be used with photosensitizers such as thiazides, tetracyclines, fluoroquinolones, phenothiazines or sulfonamides because phototoxicity may increase.

Oral exposure can cause fetal loss and malformations. Females of reproductive potential need a negative pregnancy test within 1 week before starting (sensitivity at least 50 mIU/mL), and continuous abstinence or two effective contraceptive methods during treatment and for 1 month afterward. Prior infertility does not remove the requirement unless due to hysterectomy. Males with partners of reproductive potential need effective contraception during and for 1 week afterward. Male fertility may be impaired, with reversibility unknown. Do not breastfeed during oral treatment or for 1 week after last dose.

Current Micro/Altreno observational data have not established a drug-associated major-malformation risk, but studies have limitations and do not prove safety; discuss pregnancy before use. Retin-A supplies no adequate controlled pregnancy safety data. Renova says not to use in pregnancy/when attempting pregnancy and wrinkle treatment may be postponed until nursing ends. Micro/Altreno breastfeeding requires smallest needed area and shortest duration, avoiding nipple/areola exposure. Do not equate low dermal systemic levels with zero fetal/infant exposure.

Capsules are established at ≥1 year; below 1 unestablished. Serious pediatric headache/intracranial hypertension can limit dose. Oral geriatric evidence is limited and renal/hepatic PK effects are unknown, with no label adjustment table; obtain oncology review. Acne ages: Retin-A/Micro ≥12, Altreno ≥9. Renova below 18 and above 71 unestablished; older skin may be more irritated. The selected dermal labels provide no validated renal/hepatic dose algorithm.

In APL, tretinoin promotes maturation and reduces proliferation of leukemic promyelocytes; the exact mechanism remains unknown. For acne, evidence supports reduced follicular cell cohesiveness/microcomedones and increased epithelial turnover; exact action is incompletely defined. Renova’s wrinkle-palliation mechanism is not established.

Initial peak occurs about 1–2 hours after a dose, absolute bioavailability about 50%, protein binding >95%, initial terminal half-life 0.5–2 hours. Metabolism involves CYP3A4, CYP2C8, CYP2E and UGT2B7; autoinduction lowers concentrations during repeated therapy. The selected label recommends meals although the product-specific food effect has not been characterized. Age/sex/race and renal/hepatic impairment PK effects are unknown.

Topical systemic exposure is substantially lower than oral exposure and differs by vehicle, amount, surface area and study conditions. Altreno and Micro provide formulation-specific absorption studies; they do not establish bioequivalence across creams, gels, microspheres and lotions or permit oral dose conversion.

Oncology confirms APL genetics and follows CBC/leukocytosis, differentiation-syndrome symptoms, organ function, baseline/periodic lipids, liver tests and reproductive precautions. New dyspnea, fever, swelling, sudden weight gain, severe headache or visual changes need prompt evaluation. For dermal treatment, assess irritation, UV exposure, response, adherence and pregnancy plans; no universal laboratory panel is specified.

Use exact prescribed product; tretinoin is distinct from isotretinoin and no isotretinoin program is inferred. Swallow oral capsules whole with meals and follow the missed-dose rule. For skin, use a thin layer, gentle cleanser and moisturizer, minimize UV and avoid extra applications to speed results. Follow product-specific drying waits and pregnancy guidance. Keep all products away from children and retain package instructions.

Selected capsule

10 mg, reddish-brown/yellow lengthwise shell, TR in black on yellow side.

Package

Par Health; NDC 10370-268-01, bottle 100.

U.S. status

Prescription; selected oncology indication and dermal labels separately verified. No stock or automatic interchange claim.

Oral

10 mg capsule; oncology mg/m² schedule.

Retin-A

Cream 0.025%, 0.05%, 0.1%; gel 0.01%, 0.025%.

Micro gel

0.04%, 0.06%, 0.08%, 0.1% = 0.4, 0.6, 0.8, 1 mg/g.

Altreno

Lotion 0.05% = 0.5 mg/g; pale yellow opaque.

Renova selected

Cream 0.02% = 0.2 mg/g; fine-wrinkle indication. Other brands/strengths and combinations are not automatically equivalent.

Capsules 20–25°C, tight closure, protect from light. Retin-A cream below 80°F and gel below 86°F; gel flammable, avoid fire/flame/smoking. Micro 20–25°C with 15–30°C excursions, pump upright. Altreno same controlled room-temperature range, protect from freezing and store pump upright. Renova 25°C with 15–30°C excursions. Dermal only products must never be swallowed or substituted for oncology capsules.