5/25/2023 0 Comments Tretinoin percentagesAlthough the significance of these studies to humans is not clear, patients should minimize exposure to sunlight or artificial ultraviolet irradiation sources. This effect has been confirmed in a later study in pigmented mice, and dark pigmentation did not overcome the enhancement of photocarcinogenesis by 0.05% Tretinoin. Studies in hairless albino mice suggest that concurrent exposure to Tretinoin may enhance the tumorigenic potential of carcinogenic doses of UVB and UVA light from a solar simulator. For purposes of comparisons of the animal exposure to systemic human exposure, the maximum human systemic dose is defined as 1 gram of 0.1% Tretinoin applied daily to a 50 kg person (0.02 mg Tretinoin/kg body weight). There was no evidence of carcinogenic potential when 0.025 mg/kg/day of Tretinoin was administered topically to mice (0.1 times the maximum human systemic dose, adjusted for total body surface area). The biological significance of these findings is not clear because they occurred at doses that exceeded the dermal maximally tolerated dose (MTD) of Tretinoin and because they were within the background natural occurrence rate for these tumors in this strain of mice. These doses are two and four times the maximum human systemic dose, when adjusted for total body surface area. The maximum systemic doses associated with the administered 0.017% and 0.035% formulations are 0.5 and 1.0 mg/kg/day, respectively. A dose-related incidence of liver tumors in male mice was observed at those same doses. In a 91-week dermal study in which CD-1 mice were administered 0.017% and 0.035% formulations of Tretinoin, cutaneous squamous cell carcinomas and papillomas in the treatment area were observed in some female mice. Carcinogenesis, Mutagenesis, Impairment to Fertility: It also is advisable to “rest” a patient’s skin until the effects of such preparations subside before use of Tretinoin is begun. Particular caution should be exercised in using preparations containing sulfur, resorcinol, or salicylic acid with Tretinoin. Drug Interactions:Ĭoncomitant topical medication, medicated or abrasive soaps and cleansers, soaps and cosmetics that have a strong drying effect, and products with high concentrations of alcohol, astringents, spices or lime should be used with caution because of possible interaction with Tretinoin. Tretinoin has been reported to cause severe irritation on eczematous skin and should be used with utmost caution in patients with this condition. If the degree of local irritation warrants, patients should be directed to use the medication less frequently, discontinue use temporarily, or discontinue use altogether. Topical use may induce severe local erythema and peeling at the site of application. Tretinoin preparations for acne treatment should be kept away from the eyes, the mouth, angles of the nose, and mucous membranes. Weather extremes, such as wind or cold, also may be irritating to patients under treatment with Tretinoin. Use of sunscreen products and protective clothing over treated areas is recommended when exposure cannot be avoided. Patients who may be required to have considerable sun exposure due to occupation and those with inherent sensitivity to the sun should exercise particular caution. Exposure to sunlight, including sunlamps, should be minimized during the use of Tretinoin, and patients with sunburn should be advised not to use the product until fully recovered because of heightened susceptibility to sunlight as a result of the use of Tretinoin. If a reaction suggesting sensitivity or chemical irritation occurs, use of the medication should be discontinued. Do not expose to heat or store at temperatures above 120☏ (49☌). Use of the product should be discontinued if hypersensitivity to any of the ingredients is noted. The safety and efficacy of the long-term use of this product in the treatment of other disorders have not been established. Tretinoin gel and cream are indicated for topical application in the treatment of acne vulgaris. Additionally, Tretinoin stimulates mitotic activity and increased turnover of follicular epithelial cells causing extrusion of the comedones. Although the exact mode of action of Tretinoin is unknown, current evidence suggests that topical Tretinoin decreases cohesiveness of follicular epithelial cells with decreased microcomedo formation.
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