WARNINGS
Included as part of the "PRECAUTIONS" Section
PRECAUTIONS
Hematological Effects
Methemoglobinemia
Cases of methemoglobinemia, with resultant hospitalization, have been reported postmarketing in association with twice daily dapsone gel, 5%, treatment. Patients with glucose-6-phosphate dehydrogenase deficiency or congenital or idiopathic methemoglobinemia are more susceptible to drug-induced methemoglobinemia. Avoid use of ACZONE Gel, 7.5% in those patients with congenital or idiopathic methemoglobinemia.
Signs and symptoms of methemoglobinemia may be delayed some hours after exposure. Initial signs and symptoms of methemoglobinemia are characterized by a slate grey cyanosis seen in e.g., buccal mucous membranes, lips, and nail beds. Advise patients to discontinue ACZONE Gel, 7.5% and seek immediate medical attention in the event of cyanosis.
Dapsone can cause elevated methemoglobin levels particularly in conjunction with methemoglobin-inducing agents [see DRUG INTERACTIONS].
Hemolysis
Oral dapsone treatment has produced dose-related hemolysis and hemolytic anemia. Individuals with glucose-6phosphate dehydrogenase (G6PD) deficiency are more prone to hemolysis with the use of certain drugs. G6PD deficiency is most prevalent in populations of African, South Asian, Middle Eastern, and Mediterranean ancestry.
In clinical trials, there was no evidence of clinically relevant hemolysis or hemolytic anemia in subjects treated with topical dapsone. Some subjects with G6PD deficiency using dapsone gel, 5 %, twice daily developed laboratory changes suggestive of hemolysis [see Use In Specific Populations].
Discontinue ACZONE Gel, 7.5%, if signs and symptoms suggestive of hemolytic anemia occur. Avoid use of ACZONE Gel, 7.5% in patients who are taking oral dapsone or antimalarial medications because of the potential for hemolytic reactions. Combination of ACZONE Gel, 7.5%, with trimethoprim/sulfamethoxazole
(TMP/SMX) may increase the likelihood of hemolysis in patients with G6PD deficiency [see DRUG INTERACTIONS].
Peripheral Neuropathy
Peripheral neuropathy (motor loss and muscle weakness) has been reported with oral dapsone treatment. No events of peripheral neuropathy were observed in clinical trials with topical dapsone treatment.
Skin Reactions
Skin reactions (toxic epidermal necrolysis, erythema multiforme, morbilliform and scarlatiniform reactions, bullous and exfoliative dermatitis, erythema nodosum, and urticaria) have been reported with oral dapsone treatment. These types of skin reactions were not observed in clinical trials with topical dapsone treatment.
Patient Counseling Information
Advise the patient to read the FDA-approved patient labeling (PATIENT INFORMATION).
Hematological Effects
- Inform patients that methemoglobinemia can occur with topical dapsone treatment. Advise patients to seek immediate medical attention if they develop cyanosis [see WARNINGS AND PRECAUTIONS].
- Inform patients who have G6PD deficiency that hemolytic anemia may occur with topical dapsone treatment. Advise patients to seek medical attention if they develop signs and symptoms suggestive of hemolytic anemia [see WARNINGS AND PRECAUTIONS].
Important Administration Instructions
- Advise patients to apply ACZONE Gel, 7.5%, once daily to the entire face [see DOSAGE AND ADMINISTRATION].
- ACZONE Gel, 7.5% is for topical use only.
- Do not apply ACZONE Gel, 7.5% to eyes, mouth, or mucous membranes.
Nonclinical Toxicology
Carcinogenesis, Mutagenesis, Impairment Of Fertility
Dapsone was not carcinogenic to rats when orally administered to females for 92 weeks or males for 100 weeks at dose levels up to 15 mg/kg/day (approximately 340 times the systemic exposure observed in humans as a result of use of the MRHD of ACZONE Gel, 7.5%, based on AUC comparisons).
No evidence of potential to induce carcinogenicity was observed in a dermal study in which dapsone gel was topically applied to Tg.AC transgenic mice for approximately 26 weeks. Dapsone concentrations of 3%, 5%, and 10% were evaluated; 3% material was judged to be the maximum tolerated dosage.
Dapsone was negative in a bacterial reverse mutation assay (Ames test), and was negative in a micronucleus assay conducted in mice. Dapsone was positive (clastogenic) in a chromosome aberration assay conducted with Chinese hamster ovary (CHO) cells.
The effects of dapsone on fertility and general reproductive performance were assessed in male and female rats following oral dosing. Dapsone reduced sperm motility at dosages of 3 mg/kg/day or greater (approximately 22 times the systemic exposure that is associated with the MRHD of ACZONE Gel, 7.5%, based on AUC comparisons) when administered daily beginning 63 days prior to mating and continuing through the mating period. The mean numbers of embryo implantations and viable embryos were significantly reduced in untreated females mated with males that had been dosed at 12 mg/kg/day or greater (approximately 187 times the systemic exposure that is associated with the MRHD of ACZONE Gel, 7.5%, based on AUC comparisons), presumably due to reduced numbers or effectiveness of sperm, indicating impairment of fertility. When administered to female rats at a dosage of 75 mg/kg/day (approximately 1407 times the systemic exposure that is associated with the MRHD of ACZONE Gel, 7.5%, based on AUC comparisons) for 15 days prior to mating and for 17 days thereafter, dapsone reduced the mean number of implantations, increased the mean early resorption rate, and reduced the mean litter size. These effects probably were secondary to maternal toxicity.
Use In Specific Populations
Pregnancy
Risk Summary
There are no available data on ACZONE Gel, 7.5%, use in pregnant women to inform a drug-associated risk for adverse developmental outcomes. In animal reproduction studies, oral doses of dapsone administered to pregnant rats and rabbits during organogenesis that resulted in systemic exposures more than 400 times the systemic exposure at the maximum recommended human dose (MRHD) of ACZONE Gel, 7.5%, resulted in embryocidal effects. When orally administered to rats from the onset of organogenesis through the end of lactation at systemic exposures approximately 500 times the exposure at the MRHD, dapsone resulted in increased stillbirths and decreased pup weight [see Data].
The estimated background risks of major birth defects and miscarriage for the indicated population are unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively.
Data
Animal Data
Dapsone has been shown to have an embryocidal effect in rats and rabbits when administered orally daily to females during organogenesis at dosages of 75 mg/kg/day and 150 mg/kg/day, respectively. These dosages resulted in systemic exposures that represented approximately 1407 times [rats] and 425 times [rabbits] the systemic exposure observed in human females as a result of use of the MRHD of ACZONE Gel, 7.5%, based on AUC comparisons. These effects were probably secondary to maternal toxicity.
Dapsone was assessed for effects on perinatal/postnatal pup development and postnatal maternal behavior and function in a study in which dapsone was orally administered to female rats daily beginning on the seventh day of gestation and continuing until the twenty-seventh day postpartum. Maternal toxicity (decreased body weight and food consumption) and developmental effects (increase in stillborn pups and decreased pup weight) were
seen at a dapsone dose of 30 mg/kg/day (approximately 563 times the systemic exposure that is associated with the MRHD of ACZONE Gel, 7.5%, based on AUC comparisons). No effects were observed on the viability, physical development, behavior, learning ability, or reproductive function of surviving pups.
Lactation
Risk Summary
There is no information regarding the presence of topical dapsone in breastmilk, the effects on the breastfed infant or the effects on milk production. Orally administered dapsone appears in human milk and could result in hemolytic anemia and hyperbilirubinemia especially in infants with G6PD deficiency. Systemic absorption of dapsone following topical application is minimal relative to oral dapsone administration; however, it is known that dapsone is present in human milk following administration of oral dapsone.
Pediatric Use
Safety and efficacy was evaluated in 1066 subjects aged 12-17 years old treated with ACZONE Gel, 7.5% in the clinical trials. The safety profile for ACZONE Gel, 7.5%, was similar to the vehicle control group. Safety and effectiveness of ACZONE Gel, 7.5%, have not been established in pediatric patients below the age of 12 years.
Geriatric Use
Clinical trials of ACZONE Gel, 7.5% did not include sufficient numbers of subjects aged 65 years and over to determine whether they respond differently from younger subjects.
Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency
Individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency may be more prone to methemoglobinemia and hemolysis [see WARNINGS AND PRECAUTIONS].
ACZONE Gel, 5% and vehicle were evaluated in a randomized, double-blind, cross-over design clinical study of 64 subjects with G6PD deficiency and acne vulgaris. Subjects were Black (88%), Asian (6%), Hispanic (2%) or of other racial origin (5%). Blood samples were taken at Baseline, Week 2, and Week 12 during both vehicle and ACZONE Gel, 5% treatment periods. Some of these subjects developed laboratory changes suggestive of hemolysis, but there was no evidence of clinically significant hemolytic anemia in this study [see WARNINGS AND PRECAUTIONS].