Warnings for Twyneo
Included as part of the "PRECAUTIONS" Section
Precautions for Twyneo
Hypersensitivity
Hypersensitivity reactions, including anaphylaxis, angioedema, and urticaria, have been reported with the use of benzoyl peroxide products. If a serious hypersensitivity reaction occurs, discontinue TWYNEO immediately and initiate appropriate therapy.
Skin Irritation
Patients using TWYNEO may experience application site dryness, pain, exfoliation, erythema, dermatitis, pruritis, and irritation [see ADVERSE REACTIONS]. Depending upon the severity of these adverse reactions, instruct patients to use a moisturizer, reduce the frequency of the application of TWYNEO, or discontinue use. Avoid application of TWYNEO to cuts, abrasions, eczematous, or sunburned skin.
Photosensitivity
TWYNEO may increase sensitivity to ultraviolet light. Minimize or avoid exposure to natural or artificial sunlight (tanning beds or UVA/B treatment) while using TWYNEO. Instruct patients to implement sun protection measures (e.g., sunscreen and loose-fitting clothes) when sun exposure cannot be avoided. Discontinue TWYNEO at the first evidence of sunburn.
Patient Counseling Information
Advise the patient to read the FDA-approved patient labeling (PATIENT INFORMATION).
Hypersensitivity
Inform patients that serious hypersensitivity reactions have occurred with the use of benzoyl peroxide products. If a patient experiences a serious hypersensitivity reaction, instruct patient to discontinue TWYNEO immediately and seek medical help [see WARNINGS AND PRECAUTIONS].
Skin Irritation
Inform patients that TWYNEO may cause irritation such as erythema, dryness, stinging or burning. Advise the patient to use a moisturizer for irritation [see WARNINGS AND PRECAUTIONS].
Photosensitivity
Advise patients to minimize unprotected exposure to sunlight and sunlamps; recommend the use of sunscreen products and protective apparel (e.g., hat) over treated areas when sun exposure cannot be avoided [see WARNINGS AND PRECAUTIONS].
Administration Instructions
Advise patients to apply TWYNEO exactly as directed in a thin layer, avoiding the eyes, lips, paranasal creases and mucous membranes and to wash hands immediately after application. Inform patients that TWYNEO may bleach hair or colored fabric [see DOSAGE AND ADMINISTRATION].
Discard Instructions
Instruct patients to store TWYNEO at room temperature and to discard 12 weeks after date of dispensing or 30 days after first opening, whichever is sooner [see HOW SUPPLIED].
Nonclinical Toxicology
Carcinogenesis, Mutagenesis, Impairment Of Fertility
Carcinogenicity, mutagenicity, and impairment of fertility studies were not conducted with TWYNEO.
Benzoyl Peroxide
The role of benzoyl peroxide as a tumor promoter has been well established in several animal species; however, the significance of this finding in humans is unknown.
No significant increase in tumor formation was observed in rats treated topically with 15 to 25% benzoyl peroxide carbopol gel (5 to 8 times the concentration of benzoyl peroxide in TWYNEO) for two years. Similar results were obtained in mice treated topically with 25% benzoyl peroxide carbopol gel for 56 weeks followed by intermittent treatment with 15% benzoyl peroxide gel for the rest of the two-year study period, and in mice treated topically with 5% benzoyl peroxide carbopol gel for two years. Bacterial mutagenicity assays (Ames test) conducted with benzoyl peroxide have provided mixed results. Mutagenic potential was observed in a few studies but not in a majority of investigations. Benzoyl peroxide has been found to cause DNA strand breaks in a variety of mammalian cell types and to cause sister chromatid exchanges in Chinese hamster ovary cells.
Fertility studies were not conducted with benzoyl peroxide.
Tretinoin
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. A dose-related incidence of liver tumors in male mice was observed at those same doses. The maximum systemic doses associated with the administered 0.017% and 0.035% formulations are 0.5 and 1.0 mg/kg/day, respectively. These doses are 1.3 and 2.7 times the MRHD based on BSA comparison and assuming 100% absorption. 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. There was no evidence of carcinogenic potential when 0.025 mg/kg/day of tretinoin was administered topically to mice (0.07 times the MRHD based on BSA comparison and assuming 100% absorption).
The genotoxic potential of tretinoin was evaluated in an in vitro bacterial reversion test and an in vivo rat micronucleus assay, both of which were negative.
In dermal fertility studies of another tretinoin formulation in rats, slight (not statistically significant) decreases in sperm count and motility were seen at 0.5 mg/kg/day (approximately 2.7 times the MRHD based on BSA comparison and assuming 100% absorption), and slight (not statistically significant) increases in the number and percent of nonviable embryos in females treated with 0.25 mg/kg/day and above (1.3 times the MRHD based on BSA comparison and assuming 100% absorption) were observed.
Use In Specific Populations
Pregnancy
Risk Summary
Available data from published observational studies of topical tretinoin in pregnant women have not established a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. Studies conducted with topical benzoyl peroxide have not demonstrated systemic absorption and maternal use is not expected to result in fetal exposure to benzoyl peroxide. There are no data on TWYNEO use in pregnant women.
There are reports of major birth defects reported with maternal use of topical tretinoin similar to those seen in infants exposed to oral retinoids, but these case reports do not establish a pattern or association with tretinoin-related embryopathy (see Data).
Animal reproductive studies have not been conducted with TWYNEO or benzoyl peroxide. Topical administration of tretinoin to pregnant rats during organogenesis was associated with malformations (craniofacial abnormalities [hydrocephaly], asymmetrical thyroids, variations in ossification, and increased supernumerary ribs) at doses greater than 1 mg tretinoin/kg/day, approximately 5 times the maximum recommended human dose (MRHD) based on body surface area (BSA) comparison and assuming 100% absorption. Oral administration of tretinoin to pregnant cynomolgus monkeys during organogenesis was associated with malformations at 10 mg/kg/day (approximately 100 times the MRHD based on BSA comparison and assuming 100% absorption) (see Data).
The background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of major birth defects, loss and other adverse outcomes. The background risk in the U.S. general population of major birth defects is 2 to 4% and of miscarriage is 15 to 20% of clinically recognized pregnancies.
Data
Human Data
While available studies cannot definitively establish the absence of risk, published data from multiple prospective controlled observational studies on the use of topical tretinoin products during pregnancy have not identified an association with topical tretinoin and major birth defects or miscarriage. The available studies have methodologic limitations, including small sample size and in some cases, lack of physical exam by an expert in birth defects. There are published case reports of infants exposed to topical tretinoin during the first trimester that describe major birth defects similar to those seen in infants exposed to oral retinoids; however, no pattern of malformations has been identified and no causal association has been established in these cases. The significance of these spontaneous reports in terms of risk to the fetus is not known.
Animal Data
For purposes of comparison of the animal exposure to human exposure, the MRHD is defined as 1.5 g of TWYNEO (containing 0.1% tretinoin) applied daily to a 60-kg person (0.03 mg tretinoin/kg body weight).
Topical tretinoin embryofetal development studies have generated equivocal results. There is evidence for malformations (shortened or kinked tail) after topical tretinoin administration in Wistar rats at doses greater than 1 mg/kg/day (approximately 5 times the MHRD based on BSA comparison and assuming 100% absorption). Anomalies (humerus: short 13%, bent 6%, or parietal incompletely ossified 14%) have also been reported when 10 mg/kg/day (approximately 50 times the MRHD based on BSA comparison and assuming 100% absorption) was topically applied to pregnant rats during organogenesis. Increased incidence of domed head and hydrocephaly, typical of retinoid-induced fetal malformations were noted in New Zealand White rabbits administered topical doses greater than 0.2 mg/kg/day (2.2 times the MRHD based on BSA comparison and assuming 100% absorption).
Oral tretinoin induced malformations in rats, mice, hamsters, and nonhuman primates when administered during the period of organogenesis. Fetal malformations were observed when tretinoin was orally administered to pregnant Wistar rats during organogenesis. It was teratogenic and fetotoxic in Wistar rats when given orally or topically in doses greater than 1 mg/kg/day (approximately 5 times the MRHD based on BSA comparison and assuming 100% absorption). In the cynomolgus monkey, fetal malformations were reported when an oral dose of 10 mg/kg/day was administered to pregnant monkeys during organogenesis (approximately 100 times the MRHD based on BSA comparison and assuming 100% absorption). No fetal malformations were observed at an oral dose of 5 mg/kg/day (approximately 50 times the MRHD based on BSA comparison and assuming 100% absorption). Increased skeletal variations were observed at all doses, and a dose-related increase in embryo lethality and abortion was reported in this study. Similar results have also been reported in pigtail macaques.
Oral tretinoin has been shown to be fetotoxic in rats when administered at a dose of 2.5 mg/kg/day (13 times the MRHD based on BSA comparison and assuming 100% absorption). Topical tretinoin has been shown to be fetotoxic in rabbits when administered at a dose of 0.5 mg/kg/day (5 times the MRHD based on BSA comparison and assuming 100% absorption).
Lactation
Risk Summary
There are no data on the presence of benzoyl peroxide and tretinoin or its metabolites in human milk, the effects on the breastfed infant, or the effects on milk production. It is not known whether topical administration of tretinoin could result in sufficient systemic absorption to produce detectable concentrations in human milk. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for TWYNEO and any potential adverse effects on the breastfed child from TWYNEO or from the underlying maternal condition.
Pediatric Use
The safety and effectiveness of TWYNEO for the topical treatment of acne vulgaris have been established in pediatric patients 9 years of age and older based on evidence from two multicenter, randomized, double-blind, parallel-group, vehicle-controlled, 12-week clinical trials and an open-label pharmacokinetic study. A total of 283 pediatric subjects 9 years of age and older received TWYNEO in the clinical studies [see CLINICAL PHARMACOLOGY and Clinical Studies].
The safety and effectiveness of TWYNEO in pediatric patients below 9 years of age have not been established.
Geriatric Use
Clinical trials of TWYNEO did not include sufficient numbers of subjects 65 years of age and older to determine whether they respond differently than younger subjects.