Tretinoin

Description

11 DESCRIPTION Tretinoin Gel, 0.05% is a translucent to opaque, pale yellow gel containing 0.05% tretinoin, by weight for topical administration. Chemically, tretinoin is all- trans -retinoic acid, also known as (all- E )-3,7-dimethyl-9-(2,6,6-trimethyl-1- cyclohexen-1-yl)-2,4,6,8-nonatetraenoic acid. It is a member of the retinoid class of compounds, and a metabolite of Vitamin A. Tretinoin has a molecular weight of 300.44, a molecular formula of C 20 H 28 O 2 and the following structure: Each gram of Tretinoin Gel, 0.05% contains 0.5 mg of tretinoin. Other components of this formulation are benzyl alcohol, butylparaben, butylated hydroxytoluene, carbomer homopolymer Type C, ethylparaben, fish collagen hydrolyzates, glycerin, isobutylparaben, methylparaben, octoxynol 9, phenoxyethanol, propylparaben, purified water, sodium hyaluronate, and trolamine. The contribution to efficacy of individual components of the vehicle has not been evaluated. chemstructure

What Is Tretinoin Used For?

1 INDICATIONS AND USAGE Tretinoin Gel is indicated for topical treatment of acne vulgaris. Tretinoin Gel is a retinoid indicated for topical treatment of acne vulgaris. ( 1 )

Dosage and Administration

2 DOSAGE AND ADMINISTRATION For topical use only. Not for ophthalmic, oral, or intravaginal use. Tretinoin Gel should be applied once daily, before bedtime, to the skin where acne lesions appear, using a thin layer to cover the entire affected area. Tretinoin Gel should be kept away from the eyes, the mouth, paranasal creases, and mucous membranes. Application of excessive amounts of gel will not provide incremental efficacy. Patients treated with Tretinoin Gel may use cosmetics, but the areas to be treated should be cleansed thoroughly before the medication is applied. When treating with Tretinoin Gel, caution should be exercised with the use of concomitant topical over-the-counter preparations, topical medications, medicated or abrasive soaps and cleansers, products that have strong drying effect, and products with high concentrations of alcohol, astringents, spices, or lime. Particular caution should be exercised with acne preparations containing benzoyl peroxide, sulfur, resorcinol, or salicylic acid. Allow the effects of such preparations to subside before use of Tretinoin Gel has begun.

Side Effects (Adverse Reactions)

6 ADVERSE REACTIONS The most common adverse reactions (incidence ≥5%) with Tretinoin Gel are dry skin, peeling/scaling/flaking skin, skin burning sensation, and erythema. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Obagi Cosmeceuticals LLC at 1-800-636-7546 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under prescribing conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. In two randomized, controlled trials, 674 subjects received treatment for up to 12 weeks with Tretinoin Gel [see Clinical Studies (14) ] .In these studies, 50% of the subjects who were treated with Tretinoin Gel reported one or more adverse reactions; 30% of the subjects reported treatment-related adverse reactions. In the vehicle group, 29% of the 487 randomized subjects reported at least one adverse reaction; 5% of the subjects reported events that were treatment-related. There were no serious, treatment-related adverse reactions reported by subjects in any of the treatment groups. Selected adverse reactions that occurred in at least 1% of subjects in the two trials combined are shown in Table 1 (below). Most skin-related adverse reactions first appear during the first two weeks of treatment with Tretinoin Gel, and the incidence rate for skin-related reactions peaks around the second and third week of treatment. In some subjects, the skin-related adverse reactions persist throughout the treatment period. Table 1: Number of Subjects with Selected Adverse Reactions (Occurring in at Least 1% of Subjects) Event Tretinoin Gel (n = 674) Vehicle Gel (n = 487) Dry Skin 109 (16%) 8 (2%) Peeling/Scaling/Flaking Skin 78 (12%) 7 (1%) Skin Burning Sensation 53 (8%) 8 (2%) Erythema 47 (7%) 1 (<1%) Pruritus 11 (2%) 3 (1%) Pain of Skin 7 (1%) 0 (0%) Sunburn 7 (1%) 3 (1%) 6.2 Postmarketing Experience The following adverse reactions have been identified during post-approval use of Tretinoin Gel. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Temporary hyper- or hypopigmentation has been reported with repeated application of tretinoin.

Contraindications

4 CONTRAINDICATIONS None. None ( 4 )

Pregnancy and Breastfeeding

8.1 Pregnancy Pregnancy Category C There are no well-controlled trials in pregnant women treated with Tretinoin Gel. Tretinoin Gel should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Tretinoin Gel at doses of 0.1, 0.3 and 1 g/kg/day was tested for maternal and developmental toxicity in pregnant Sprague-Dawley rats by dermal application. The dose of 1 g/kg/day was approximately 4 times the clinical dose assuming 100% absorption and based on body surface area comparison. Possible tretinoin-associated teratogenic effects (craniofacial abnormalities (hydrocephaly), asymmetrical thyroids, variations in ossification, and increased supernumerary ribs) were noted in the fetuses of Tretinoin Gel treated animals. These findings were not observed in control animals. Other maternal and reproductive parameters in the Tretinoin Gel treated animals were not different from control. For purposes of comparison of the animal exposure to human exposure, the clinical dose is defined as 2 g of Tretinoin Gel applied daily to a 50 kg person. Oral tretinoin has been shown to be teratogenic in rats, mice, rabbits, hamsters and nonhuman primates. Tretinoin was teratogenic in Wistar rats when given orally in doses greater than 1 mg/kg/day (approximately 8 times the clinical dose based on body surface area comparison). In the cynomolgus monkey, fetal malformations were reported for doses of 10 mg/kg/day, but none were observed at 5 mg/kg/day (approximately 80 times the clinical dose based on body surface area comparison), although increased skeletal variations were observed at all doses. Dose-related increases in embryolethality and abortion also were reported. Similar results have also been reported in pigtail macaques. Topical tretinoin in a different formulation has generated equivocal results in animal teratogenicity tests. There is evidence for teratogenicity (shortened or kinked tail) of topical tretinoin in Wistar rats at doses...

8.3 Nursing Mothers It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Tretinoin Gel is administered to a nursing woman.

How Supplied

16 HOW SUPPLIED/STORAGE AND HANDLING Tretinoin Gel, 0.05% is a translucent to opaque, pale yellow topical gel and available as: