Prescription Drugs

CLINICAL PHARMACOLOGY Actions The mechanism of action in Dermatitis herpetiformis has not been established. By the kinetic method in mice, Dapsone is bactericidal as well as bacteriostatic against Mycobacterium leprae. Absorption and Excretion Dapsone, when given orally, is rapidly and almost completely absorbed. About 85 percent of the daily intake is recoverable from the urine mainly in the form of water-soluble metabolites. Excretion of the drug is slow and a constant blood level can be maintained with the usual dosage. Blood Levels Detected a few minutes after ingestion, the drug reaches peak concentration in 4-8 hours. Daily administration for at least eight days is necessary to achieve a plateau level. With doses of 200 mg daily, this level averaged 2.3 μg/ml with a range of 0.1-7.0 μg/ml. The half-life in the plasma in different individuals varies from ten hours to fifty hours and averages twenty-eight hours. Repeat tests in the same individual are constant. Daily administration (50 - 100 mg) in leprosy patients will provide blood levels in excess of the usual minimum inhibitory concentration even for patients with a short Dapsone half-life.

CLINICAL PHARMACOLOGY Mechanism Of Action The mechanism of action of dapsone gel in treating acne vulgaris is not known. Pharmacokinetics An open-label study compared the pharmacokinetics of dapsone after ACZONE® Gel, 5%, (110 ± 60 mg/day) was applied twice daily (~BSA 22.5%) for 14 days (n=18) with a single 100 mg dose of oral dapsone administered to a subgroup of patients (n=10) in a crossover design. On Day 14 the mean dapsone AUC0-24h was 415 ± 224 ng•h/mL for ACZONE® Gel, 5%, whereas following a single 100 mg dose of oral dapsone the AUC0-infinity was 52,641 ± 36,223 ng•h/mL. Exposure after the oral dose of 100 mg dapsone was approximately 100 times greater than after the topical ACZONE® Gel, 5% dose, twice a day. In a long-term safety study of ACZONE® Gel, 5% treatment, periodic blood samples were collected up to 12 months to determine systemic exposure of dapsone and its metabolites in approximately 500 patients. Based on the measurable dapsone concentrations from 408 patients (M=192, F=216), obtained at month 3, neither gender, nor race appeared to affect the pharmacokinetics of dapsone. Similarly, dapsone exposures were approximately the same between the age groups of 12-15 years (N=155) and those greater than or equal to 16 years (N=253). There was no evidence of increasing systemic exposure to dapsone over the study year in these patients. Microbiology In Vivo Activity No microbiology or immunology studies were conducted during dapsone gel clinical trials. Drug Resistance No dapsone resistance studies were conducted during dapsone gel clinical trials. Because no microbiology studies were done, there are no data available as to whether dapsone treatment may have resulted in decreased susceptibility of Propionibacterium acnes, an organism associated with acne, to other antimicrobials that may be used to treat acne. Therapeutic resistance to dapsone has been reported for Mycobacterium leprae, when patients have been treated with oral dapsone. Clinical Studies Two randomized, double-blind, vehicle-controlled, clinical studies were conducted to evaluate ACZONE® Gel, 5%, for the treatment of patients with acne vulgaris (N=1475 and 1525). The studies were designed to enroll patients 12 years of age and older with 20 to 50 inflammatory and 20 to 100 non-inflammatory lesions at baseline. In these studies patients applied either ACZONE® Gel, 5%, or vehicle control twice daily for up to 12 weeks. Efficacy was evaluated in terms of success on the Global Acne Assessment Score (no or minimal acne) and in the percent reduction in inflammatory, non-inflammatory, and total lesions. The Global Acne Assessment Score was a 5-point scale as follows: 0 None: no evidence of facial acne vulgaris 1 Minimal: few non-inflammatory lesions (comedones) are present; a few inflammatory lesions (papules/pustules) may be present 2 Mild: several to many non-inflammatory lesions (comedones) are present; a few inflammatory lesions (papules/pustules) are present 3 Moderate: many non-inflammatory (comedones) and inflammatory lesions (papules/pustules) are present; no nodulo-cystic lesions are allowed 4 Severe: significant degree of inflammatory disease; papules/pustules are a predominant feature; a few nodulo-cystic lesions may be present; comedones may be present. The success rates on the Global Acne Assessment Score (no or minimal acne) at Week 12 are presented in Table 4. Table 4 : Success (No or Minimal Acne) on the Global Acne Assessment Score at Week 12 Study 1* Study 2* ACZONE® N=699 Vehicle N=687 ACZONE® N=729 Vehicle N=738 Subjects with No or Minimal Acne 291 (42%) 223 (32%) 253 (35%) 206 (28%) *Analysis excludes subjects classified with minimal acne at baseline Table 5 presents the mean percent reduction in inflammatory, non-inflammatory, and total lesions from baseline to Week 12. Table 5 : Percent Reduction in Lesions from Baseline to Week 12 Study 1 Study 2 ACZONE® N=745 Vehicle N=740 ACZONE® N=761 Vehicle N=764 Inflammatory 46% 42% 48% 40% Non-Infl ammatory 31% 24% 30% 21% Total 38% 32% 37% 29% The clinical studies enrolled about equal proportions of male and female subjects. Female patients tended to have greater percent reductions in lesions and greater success on the Global Acne Assessment Score than males. The breakdown by race in the clinical studies was about 73% Caucasian, 14% Black, 9% Hispanic, and 2% Asian. Efficacy results were similar across the racial subgroups.

DAPSONE Tablets , USP (diaminodiphenylsulfone) 25 mg & 100 mg Tablets for Oral Use DESCRIPTION Dapsone-USP, 4,4'-diaminodiphenylsulfone (DDS), is a primary treatment for Dermatitis herpetiformis. It is an antibacterial drug for susceptible cases of leprosy. It is a white, odorless crystalline powder, practically in-soluble in water and insoluble in fixed and vegetable oils. Dapsone is issued on prescription in tablets of 25 and 100 mg for oral use. Inactive Ingredients: Colloidal silicone dioxide, magnesium stearate, microcrystalline cellulose and corn starch.

Find Lowest Prices on ACZONE® (dapsone) Topical Gel, USP DESCRIPTION ACZONE® Gel, 5%, contains dapsone, a sulfone, in an aqueous gel base for topical dermatologic use. ACZONE® Gel, 5% is a gritty translucent material with visible drug substance particles. Chemically, dapsone has an empirical formula of C12H12N2O2S. It is a white, odorless crystalline powder that has a molecular weight of 248. Dapsone's chemical name is 4,4'-diaminodiphenylsulfone and its structural formula is: Each gram of ACZONE® Gel, 5%, contains 50 mg of dapsone, USP, in a gel of carbomer homopolymer type C; diethylene glycol monoethyl ether, NF; methylparaben, NF; sodium hydroxide, NF; and purified water, USP.

INDICATIONS Dermatitis herpetiformis: (D.H.) Leprosy: All forms of leprosy except for cases of proven Dapsone resistance. DOSAGE AND ADMINISTRATION Dermatitis Herpetiformis The dosage should be individually titrated starting in adults with 50 mg daily and correspondingly smaller doses in children. If full control is not achieved within the range of 50-300 mg daily, higher doses may be tried. Dosage should be reduced to a minimum maintenance level as soon as possible. In responsive patients there is a prompt reduction in pruritus followed by clearance of skin lesions. There is no effect on the gastrointestinal component of the disease. Dapsone levels are influenced by acetylation rates. Patients with high acetylation rates, or who are receiving treatment affecting acetylation may require an adjustment in dosage. A strict gluten free diet is an option for the patient to elect, permitting many to reduce or eliminate the need for Dapsone; the average time for dosage reduction is 8 months with a range of 4 months to 2 ½ years and for dosage elimination 29 months with a range of 6 months to 9 years. Leprosy In order to reduce secondary Dapsone resistance, the WHO Expert Committee on Leprosy and the USPHS at Carville, LA, recommended that Dapsone should be commenced in combination with one or more anti-leprosy drugs. In the multidrug program Dapsone should be maintained at the full dosage of 100 mg daily without interruption (with corresponding smaller doses for children) and provided to all patients who have sensitive organisms with new or recrudescent disease or who have not yet completed a two year course of Dapsone monotherapy. For advice and other drugs, the USPHS at Carville, LA (1-800-642-2477) should be contacted. Before using other drugs consult appropriate product labeling. In bacteriologically negative tuberculoid and indeterminate disease, the recommendation is the coadministration of Dapsone 100 mg daily with six months of Rifampin 600 mg daily. Under WHO, daily Rifampin may be replaced by 600 mg Rifampin monthly, if supervised. The Dapsone is continued until all signs of clinical activity are controlled - usually after an additional six months. Then Dapsone should be continued for an additional three years for tuberculoid and indeterminate patients and for five years for borderline tuberculoid patients. In lepromatous and borderline lepromatous patients, the recommendation is the co-administration of Dapsone 100 mg daily with two years of Rifampin 600 mg daily. Under WHO daily Rifampin may be replaced by 600 mg Rifampin monthly, if supervised. One may elect the concurrent administration of a third anti-leprosy drug, usually either Clofazamine 50-100 mg daily or Ethionamide 250-500 mg daily. Dapsone 100 mg daily is continued 3-10 years until all signs of clinical activity are controlled with skin scrapings and biopsies negative for one year. Dapsone should then be continued for an additional 10 years for borderline patients and for life for lepromatous patients. Secondary Dapsone resistance should be suspected whenever a lepromatous or borderline lepromatous patient receiving Dapsone treatment relapses clinically and bacteriologically, solid staining bacilli being found in the smears taken from the new active lesions. If such cases show no response to regular and supervised Dapsone therapy within three to six months or good compliance for the past 3-6 months can be assured, Dapsone resistance should be considered confirmed clinically. Determination of drug sensitivity using the mouse footpad method is recommended and, after prior arrangement, is available without charge from the USPHS, Carville, LA. Patients with proven Dapsone resistance should be treated with other drugs. Leprosy Reactional States Abrupt changes in clinical activity occur in leprosy with any effective treatment and are known as reactional states. The majority can be classified into two groups. The “Reversal” reaction (Type 1) may occur in borderline or tuberculoid leprosy patients often soon after chemotherapy is started. The mechanism is presumed to result from a reduction in the antigenic load: the patient is able to mount an enhanced delayed hypersensitivity response to residual infection leading to swelling (“Reversal”) of existing skin and nerve lesions. If severe, or if neuritis is present, large doses of steroids should always be used. If severe, the patient should be hospitalized. In general anti-leprosy treatment is continued and therapy to suppress the reaction is indicated such as analgesics, steroids, or surgical decompression of swollen nerve trunks. USPHS at Carville, LA should be contacted for advice in management. Erythema nodosum leprosum (ENL) (lepromatous reaction) (Type 2 reaction) occurs mainly in lepromatous patients and small numbers of borderline patients. Approximately 50% of treated patients show this reaction in the first year. The principal clinical features are fever and tender erythematous skin nodules sometimes associated with malaise, neuritis, orchitis, albuminuria, joint swelling, iritis, epistaxis or depression. Skin lesions can become pustular and/or ulcerate. Histologically there is a vasculitis with an intense polymorphonuclear infiltrate. Elevated circulating immune complexes are considered to be the mechanism of reaction. If severe, patients should be hospitalized. In general, antileprosy treatment is continued. Analgesics, steroids, and other agents available from USPHS, Carville, LA, are used to suppress the reaction. HOW SUPPLIED Dapsone Tablets USP, 25 mg are available as round white scored tablets, debossed “25” above and “102” below the score and on the obverse “JACOBUS” in a Unit of Use carton of 30 tablets (2 x 15). The blisters are light and child-resistant. NDC 49938-102-30. Dapsone Tablets USP, 100 mg are available as round white scored tablets, debossed “100” above and “101” below the score and on the obverse “JACOBUS” in a Unit of Use carton of 30 tablets (2 x 15).The blisters are light and child-resistant. NDC 49938-101-30. Dapsone Tablets USP, 25 mg are available as round white scored tablets, debossed “25” above and “102” below the score and on the obverse “JACOBUS” in a Unit of Use carton of 28 tablets (2 x 14). The blisters are light and child-resistant. NDC 49938-102-28. Dapsone Tablets USP, 100 mg are available as round white scored tablets, debossed“100” above and “101” below the score and on the obverse “JACOBUS” in a Unit of Use carton of 28 tablets (2 x 14). The blisters are light and child-resistant. NDC 49938-101-28. Store at 20°- 25° C (68°- 77°F). [see USP Controlled Room Temperature]. Protect from light. Keep this and all medication out of the reach of children. Jacobus Pharmaceutical Co., Inc. P.O. Box 5290, Princeton, NJ 08540.

INDICATIONS ACZONE® Gel, 5%, is indicated for the topical treatment of acne vulgaris. DOSAGE AND ADMINISTRATION For topical use only. Not for oral, ophthalmic, or intravaginal use. After the skin is gently washed and patted dry, apply approximately a pea-sized amount of ACZONE® Gel, 5%, in a thin layer to the acne affected areas twice daily. Rub in ACZONE® Gel, 5%, gently and completely. ACZONE® Gel, 5%, is gritty with visible drug substance particles. Wash hands after application of ACZONE® Gel, 5%. If there is no improvement after 12 weeks, treatment with ACZONE® Gel, 5%, should be reassessed. HOW SUPPLIED Dosage Forms And Strengths Gel, 5%. Each gram of ACZONE® gel contains 50 mg of dapsone in a white to pale yellow gel. Storage And Handling ACZONE® (dapsone) Gel, 5%, is supplied in the following size tubes: NDC 0023-3670-30 30 gram laminate tube NDC 0023-3670-60 60 gram laminate tube NDC 0023-3670-90 90 gram laminate tube Store ACZONE® gel at controlled room temperature, 20°-25°C (68°-77°F), excursions permitted to 15°-30°C (59°-86°F). Protect from freezing. Allergan, Inc., Irvine, CA 92612, U.S.A. Revised: July 2015

PATIENT INFORMATION No information provided. Please refer to the WARNINGS and PRECAUTIONS sections.

PATIENT INFORMATION ACZONE® (AK-zon) (dapsone) Gel, 5% Important: For use on skin only (topical use). Do not use ACZONE® Gel, 5% in or on your mouth, eyes, or vagina. What is ACZONE® Gel, 5%? ACZONE® Gel, 5% is a prescription medicine used on your skin (topical) to treat acne vulgaris. ACZONE® Gel has not been studied in children under 12 years of age. Before using ACZONE® Gel, 5%, tell your doctor about all of your medical conditions, including if you: Have glucose-6-phosphate dehydrogenase deficiency (G6PD) Have higher than normal levels of methemoglobin in your blood (methemoglobinemia) Are pregnant or plan to become pregnant. It is not known if ACZONE® Gel, 5 % will harm your unborn baby. Are breastfeeding or plan to breastfeed. ACZONE® Gel, 5% can pass into your breast milk and may harm your baby. You and your doctor should decide if you will use ACZONE® Gel, 5% or breastfeed. You should not do both. Tell your doctor about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Especially tell your doctor if you are using acne medicines that contain benzoyl peroxide. Use of benzoyl peroxide with ACZONE® Gel, 5% at the same time may cause your skin or facial hair to temporarily turn yellow or orange at the site of application. How should I use ACZONE® Gel, 5%? Use ACZONE® Gel, 5% exactly as your doctor tells you. Apply ACZONE® Gel, 5% twice a day. Gently wash and pat dry the areas of your skin where you will apply ACZONE® Gel, 5%. Apply a pea-sized amount of ACZONE® Gel, 5% in a thin layer to the areas of your skin that have acne. Rub ACZONE® Gel, 5% in gently and completely. It may feel gritty and you may see particles in the gel. Make sure to put the cap back on the ACZONE® Gel tube. Close it tightly. Wash your hands after applying ACZONE® Gel, 5%. Do not swallow ACZONE® Gel. If you swallow ACZONE® Gel, call your doctor or poison control center right away. If your acne does not get better after using ACZONE® Gel, 5% for 12 weeks, talk to your doctor about continuing treatment. What are the possible side effects of ACZONE® Gel, 5%? ACZONE® Gel, 5% may cause serious side effects, including: Decrease of oxygen in your blood caused by a certain type of abnormal red blood cell methemoglobinemia). Stop using ACZONE® Gel, 5% and get medical help right away if your lips, nail beds, or the inside of your mouth turns grey or blue. Breakdown of red blood cells (hemolytic anemia). Some people with G6PD deficiency using ACZONE® Gel, 5% have developed mild hemolytic anemia. Stop using ACZONE® Gel, 5% and tell your doctor right away if you get any of the following signs and symptoms: back pain shortness of breath tiredness or weakness dark brown urine fever yellow or pale skin The most common side effects of ACZONE® Gel, 5% include oiliness, peeling, dryness, and redness of the skin being treated. These are not all of the possible side effects of ACZONE® Gel, 5%. Call your doctor for medical advice about side effects.  You may report side effects to FDA at 1-800-FDA-1088. How should I store ACZONE® Gel, 5%? Store ACZONE® Gel, 5% at room temperature 68°F to 77°F (20°C to 25°C). Protect ACZONE® Gel, 5% from freezing. Keep ACZONE® Gel, 5% and all medicines out of the reach of children. General information about the safe and effective use of ACZONE® Gel, 5%? Medicines are sometimes prescribed for purposes other than those listed in a Patient Information leaflet. Do not use ACZONE® Gel, 5% for a condition for which it was not prescribed. Do not give ACZONE® Gel, 5% to other people, even if they have the same symptoms that you have. It may harm them. You can ask your pharmacist or doctor for information about ACZONE® Gel, 5% that is written for health professionals. What are the ingredients in ACZONE® Gel, 5%? Active ingredient: dapsone Inactive ingredients: carbomer homopolymer type C, diethylene glycol monoethyl ether, methylparaben, sodium hydroxide, and purified water, USP.

OVERDOSE Nausea, vomiting, hyperexcitability can appear a few minutes up to 24 hours after ingestion of an overdosage. Methemoglobin induced depression, convulsions or severe cyanosis requires prompt treatment. In normal and methemoglobin reductase deficient patients, methylene blue, 1-2 mg/kg of body weight, given slowly intravenously, is the treatment of choice. The effect is complete in 30 minutes, but may have to be repeated if methemoglobin reaccumulates. For non-emergencies, if treatment is needed, methylene blue may be given orally in doses of 3-5 mg/kg every 4-6 hours. Methylene blue reduction depends on G6PD and should not be given to fully expressed G6PD deficient patients. CONTRAINDICATIONS Hypersensitivity to Dapsone and/or its derivatives.

OVERDOSE No information provided. CONTRAINDICATIONS None.

SIDE EFFECTS In addition to the warnings listed above, the following syndromes and serious reactions have been reported in patients on Dapsone. Hematologic Effects Dose-related hemolysis is the most common adverse effect and is seen in patients with or without G6PD deficiency. Almost all patients demonstrate the inter-related changes of a loss of 1-2g of hemoglobin, an increase in the reticulocytes (2-12%), a shortened red cell life span and a rise in methemoglobin. G6PD deficient patients have greater responses. Nervous System Effects Peripheral neuropathy is a definite but unusual complication of Dapsone therapy in non-leprosy patients. Motor loss is predominant. If muscle weakness appears, Dapsone should be withdrawn. Recovery on withdrawal is usually substantially complete. The mechanism of recovery is reported by axonal regeneration. Some recovered patients have tolerated retreatment at reduced dosage. In leprosy this complication may be difficult to distinguish from a leprosy reactional state. Body As A Whole: In addition to the warnings and adverse effects reported above, additional adverse reactions include: nausea, vomiting, abdominal pains, pancreatitis, vertigo, blurred vision, tinnitus, insomnia, fever, headache, psychosis, phototoxicity, pulmonary eosinophilia, tachycardia, albuminuria, the nephrotic syndrome, hypoalbuminemia without proteinuria, renal papillary necrosis, male infertility, drug-induced Lupus erythematosus and an infectious mononucleosis-like syndrome. In general, with the exception of the complications of severe anoxia from overdosage (retinal and optic nerve damage, etc.) these adverse reactions have regressed off drug. DRUG INTERACTIONS Rifampin lowers Dapsone levels 7 to 10-fold by accelerating plasma clearance; in leprosy this reduction has not required a change in dosage. Folic acid antagonists such as pyrimethamine may increase the likelihood of hematologic reactions. A modest interaction has been reported for patients receiving 100 mg Dapsone daily in combination with trimethoprim 5 mg/kg q6h. On Day 7, the serum Dapsone levels averaged 2.1 ± 1.0 μg/mL in comparison to 1.5 ± 0.5 μg/mL for Dapsone alone. On Day 7, trimethoprim levels averaged 18.4 ± 5.2 μg/mL in comparison to 12.4 ± 4.5 μg/mL for patients not receiving Dapsone. Thus, there is a mutual interaction between Dapsone and trimethoprim in which each raises the level of the other about 1.5 times. A crossover study1 designed to assess the potential of a drug interaction between Dapsone, 100 mg/day and trimethoprim, 200 mg every 12 hours, in eight asymptomatic HIV positive volunteers (average CD4 count 524 cells/mm ) demonstrated that there was not a significant drug intreraction between Dapsone and trimethoprim. However, an earlier report2 also by Lee et al, in 78 HIV infected patients with acute Pneumocystis carinii pneumonia, receiving Dapsone, 100 mg/day and higher trimethoprim dose, 20 mg/kg/day, demonstrated that the serum levels of Dapsone were increased by 40% and trimethoprim levels were increased by 48% when the drugs were administered concurrently.

SIDE EFFECTS Clinical Studies Experience Because clinical trials are conducted under widely varying 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. Serious adverse reactions reported in patients treated with ACZONE® Gel, 5%, during clinical trials included but were not limited to the following: Nervous system/Psychiatric – Suicide attempt, tonic clonic movements. Gastrointestinal – Abdominal pain, severe vomiting, pancreatitis. Other – Severe pharyngitis In the clinical trials, a total of 12 out of 4032 patients were reported to have depression (3 of 1660 treated with vehicle and 9 of 2372 treated with ACZONE® Gel, 5%). Psychosis was reported in 2 of 2372 patients treated with ACZONE® Gel, 5%, and in 0 of 1660 patients treated with vehicle. Combined contact sensitization/irritation studies with ACZONE® Gel, 5%, in 253 healthy subjects resulted in at least 3 subjects with moderate erythema. ACZONE® Gel, 5%, did not induce phototoxicity or photoallergy in human dermal safety studies. ACZONE® Gel, 5%, was evaluated for 12 weeks in four controlled studies for local cutaneous events in 1819 patients. The most common events reported from these studies include oiliness/peeling, dryness, and erythema. These data are shown by severity in Table 1 below. Table 1 : Application Site Adverse Reactions by Maximum Severity Application Site Event ACZONE® (N=1819) Vehicle (N=1660) Mild Moderate Severe Mild Moderate Severe Erythema 9% 5% < 1% 9% 6% < 1% Dryness 14% 3% < 1% 14% 4% < 1% Oiliness/Peeling 13% 6% < 1% 15% 6% < 1% The adverse reactions occurring in at least 1% of patients in either arm in the four vehicle controlled studies are presented in Table 2. Table 2 : Adverse Reactions Occurring in at Least 1% of Patients ACZONE® N=1819 Vehicle N=1660 Application Site Reaction NOS 18% 20% Application Site Dryness 16% 17% Application Site Erythema 13% 14% Application Site Burning 1% 2% Application Site Pruritus 1% 1% Pyrexia 1% 1% Nasopharyngitis 5% 6% Upper Respiratory Tract Inf. NOS 3% 3% Sinusitis NOS 2% 1% Influenza 1% 1% Pharyngitis 2% 2% Cough 2% 2% Joint Sprain 1% 1% Headache NOS 4% 4% NOS = Not otherwise specified One patient treated with ACZONE® Gel in the clinical trials had facial swelling which led to discontinuation of medication. In addition, 486 patients were evaluated in a 12 month safety study. The adverse event profile in this study was consistent with that observed in the vehicle-controlled studies. Experience With Oral Use Of Dapsone Although not observed in the clinical trials with ACZONE® Gel (topical dapsone) serious adverse reactions have been reported with oral use of dapsone, including agranulocytosis, hemolytic anemia, peripheral neuropathy (motor loss and muscle weakness), and skin reactions (toxic epidermal necrolysis, erythema multiforme, morbilliform and scarlatiniform reactions, bullous and exfoliative dermatitis, erythema nodosum, and urticaria). Postmarketing Experience The following adverse reactions have been identified during post-approval use of ACZONE® Gel, 5%. 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. Methemoglobinemia has been identified during postmarketing use of ACZONE® Gel, 5% [see WARNINGS AND PRECAUTIONS]. DRUG INTERACTIONS Trimethoprim-Sulfamethoxazole A drug-drug interaction study evaluated the effect of the use of ACZONE® Gel, 5%, in combination with double strength (160 mg/800 mg) trimethoprim-sulfamethoxazole (TMP/SMX). During co-administration, systemic levels of TMP and SMX were essentially unchanged. However, levels of dapsone and its metabolites increased in the presence of TMP/SMX. Systemic exposure (AUC0-12) of dapsone and N-acetyl-dapsone (NAD) were increased by about 40% and 20% respectively in the presence of TMP/SMX. Notably, systemic exposure (AUC0-12) of dapsone hydroxylamine (DHA) was more than doubled in the presence of TMP/SMX. Exposure from the proposed topical dose is about 1% of that from the 100 mg oral dose, even when co-administered with TMP/SMX. Topical Benzoyl Peroxide Topical application of ACZONE® Gel followed by benzoyl peroxide in subjects with acne vulgaris resulted in a temporary local yellow or orange discoloration of the skin and facial hair (reported by 7 out of 95 subjects in a clinical study) with resolution in 4 to 57 days. Drug Interactions With Oral Dapsone Certain concomitant medications (such as rifampin, anticonvulsants, St. John's wort) may increase the formation of dapsone hydroxylamine, a metabolite of dapsone associated with hemolysis. With oral dapsone treatment, folic acid antagonists such as pyrimethamine have been noted to possibly increase the likelihood of hematologic reactions. Concomitant Use With Drugs That Induce Methemoglobinemia Concomitant use of ACZONE® with drugs that induce methemoglobinemia such as sulfonamides, acetaminophen, acetanilide, aniline dyes, benzocaine, chloroquine, dapsone, naphthalene, nitrates and nitrites, nitrofurantoin, nitroglycerin, nitroprusside, pamaquine, para-aminosalicylic acid, phenacetin, phenobarbital, phenytoin, primaquine, and quinine may increase the risk for developing methemoglobinemia [see WARNINGS AND PRECAUTIONS].

WARNINGS The patient should be warned to respond to the presence of clinical signs such as sore throat, fever, pallor, purpura or jaundice. Deaths associated with the administration of Dapsone have been reported from agranulocytosis, aplastic anemia and other blood dyscrasias. Complete blood counts should be done frequently in patients receiving Dapsone. The FDA Dermatology Advisory Committee recommended that, when feasible, counts should be done weekly for the first month, monthly for six months and semi-annually thereafter. If a significant reduction in leucocytes, platelets or hemopoiesis is noted, Dapsone should be discontinued and the patient followed intensively. Folic acid antagonists have similar effects and may increase the incidence of hematologic reactions; if co-administered with Dapsone the patient should be monitored more frequently. Patients on weekly pyrimethamine and Dapsone have developed agranulocytosis during the second and third month of therapy. Severe anemia should be treated prior to initiation of therapy and hemoglobin monitored. Hemolysis and methemoglobin may be poorly tolerated by patients with severe cardiopulmonary disease. Cutaneous reactions, especially bullous, include exfoliative dermatitis and are probably one of the most serious, though rare, complications of sulfone therapy. They are directly due to drug sensitization. Such reactions include toxic erythema, erythema multiforme, toxic epidermal necrolysis, morbilliform and scarlatiniform reactions, urticaria and erythema nodosum. If new or toxic dermatologic reactions occur, sulfone therapy must be promptly discontinued and appropriate therapy instituted. Leprosy reactional states, including cutaneous, are not hypersensitivity reactions to Dapsone and do not require discontinuation. See special section. PRECAUTIONS General Hemolysis and Heinz body formation may be exaggerated in individuals with a glucose-6- phosphate dehydrogenase (G6PD) deficiency, or methemoglobin reductase deficiency, or hemoglobin M. This reaction is frequently dose-related. Dapsone should be given with caution to these patients or if the patient is exposed to other agents or conditions such as infection or diabetic ketosis capable of producing hemolysis. Drugs or chemicals which have produced significant hemolysis in G6PD or methemoglobin reductase deficient patients include Dapsone, sulfanilamide, nitrite, aniline, phenylhydrazine, napthalene, niridazole, nitro-furantoin and 8-amino-antimalarials such as primaquine. Toxic hepatitis and cholestatic jaundice have been reported early in therapy. Hyperbilirubinemia may occur more often in G6PD deficient patients. When feasible, baseline and subsequent monitoring of liver function is recommended; if abnormal, Dapsone should be discontinued until the source of the abnormality is established. Carcinogenesis, Mutagenesis Dapsone has been found carcinogenic (sarcomagenic) for male rats and female mice causing mesenchymal tumors in the spleen and peritoneum, and thyroid carcinoma in female rats. Dapsone is not mutagenic with or without microsomal activation in S. typhimurium tester strains 1535, 1537, 1538, 98, or 100. Pregnancy Teratogenic Effects - Pregnancy Category C Animal reproduction studies have not been conducted with Dapsone. Extensive, but uncontrolled experience and two published surveys on the use of Dapsone in pregnant women have not shown that Dapsone increases the risk of fetal abnormalities if administered during all trimesters of pregnancy or can affect reproduction capacity. Because of the lack of animal studies or controlled human experience, Dapsone should be given to a pregnant woman only if clearly needed. In general, for leprosy, USPHS at Carville recommends maintenance of Dapsone. Dapsone has been important for the management of some pregnant D.H. patients. Nursing Mothers Dapsone is excreted in breast milk in substantial amounts. Hemolytic reactions can occur in neonates. See section on hemolysis. Because of the potential for tumorgenicity shown for Dapsone in animal studies a decision should be made whether to discontinue nursing or discontinue the drug taking into account the importance of drug to the mother. Pediatric Use Pediatric patients are treated on the same schedule as adults but with correspondingly smaller doses. Dapsone is generally not considered to have an effect on the later growth, development and functional development of the pediatric patient. REFERENCES 1. Lee, B., et al., Zidovudine, Trimethoprim, and Dapsone Pharmacokinetic Interactions in Patients with HIV Infection. Antimicrobial Agents and Chemotherapy, May 1996; 1231-1236. 2. Lee, B., et al., Dapsone, Trimethoprim, and Sulfamethoxazole Plasma Levels During Treatment of Pneumocystis Carinii Pneumonia in Patients with AIDS, Annals of Internal Medicine, 1989; 110:606-611.

WARNINGS Included as part of the PRECAUTIONS section. PRECAUTIONS Methemoglobinemia Cases of methemoglobinemia, with resultant hospitalization, have been reported postmarketing in association with ACZONE® 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, 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, 5% and seek immediate medical attention in the event of cyanosis. Dapsone can cause elevated methemoglobin levels particularly in conjunction with methemoglobin-inducing agents. Hematologic Effects Oral dapsone treatment has produced dose-related hemolysis and hemolytic anemia. Individuals with glucose-6-phosphate 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. Some subjects with G6PD deficiency using ACZONE® Gel developed laboratory changes suggestive of hemolysis. There was no evidence of clinically relevant hemolysis or anemia in patients treated with ACZONE® Gel, 5%, including patients who were G6PD deficient. Discontinue ACZONE® Gel, 5%, if signs and symptoms suggestive of hemolytic anemia occur. Avoid use of ACZONE® Gel, 5% in patients who are taking oral dapsone or antimalarial medications because of the potential for hemolytic reactions. Combination of ACZONE® Gel, 5%, with trimethoprim/sulfamethoxazole (TMP/SMX) may increase the likelihood of hemolysis in patients with G6PD deficiency. 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 ACZONE® Gel, 5% treatment. Skin 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 ACZONE® Gel, 5% treatment. Patient Counseling Information See FDA-approved patient labeling (PATIENT INFORMATION) Advise patient to seek immediate medical attention for cyanosis [see WARNINGS AND PRECAUTIONS]. Advise patient to use ACZONE® Gel, 5%, as directed by the physician. ACZONE® Gel, 5%, is for external topical use only. ACZONE® Gel, 5%, is not for oral, ophthalmic or intravaginal use. Advise patients to report any signs of adverse reactions to their physician. Protect ACZONE® Gel, 5%, from freezing. See Patient Information for additional information on safety, efficacy, general use, and storage of ACZONE® Gel, 5%. Nonclinical Toxicology Carcinogenesis, Mutagenesis, Impairment Of Fertility Dapsone was not mutagenic in a bacterial reverse mutation assay (Ames test) using S. typhimurium and E. coli, with and without metabolic activation and was negative in a micronucleus assay conducted in mice. Dapsone increased both numerical and structural aberrations in a chromosome aberration assay conducted with Chinese hamster ovary (CHO) cells. 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 160 times the systemic exposure observed in human males and 300 times the systemic exposure observed in human females as a result of use of the maximum recommended topical dose, based on AUC comparisons). No evidence of potential to induce carcinogenicity was obtained 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. ACZONE® Gel, 5%, did not increase the rate of formation of ultraviolet light-induced skin tumors when topically applied to hairless mice in a 12-month photocarcinogenicity study. The effects of dapsone on fertility and general reproduction performance were assessed in male and female rats following oral (gavage) dosing. Dapsone reduced sperm motility at dosages of 3 mg/kg/day or greater (approximately 17 times the systemic exposure observed in human males as a result of use of the maximum recommended topical dose, based on AUC comparisons). 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 70 times the systemic exposure observed in human males as a result of use of the maximum recommended topical dose, based on AUC comparisons), presumably due to reduced numbers or effectiveness of sperm, indicating impairment of fertility. Dapsone had no effect on male fertility at dosages of 2 mg/kg/day or less (approximately 13 times the systemic exposure observed in human males as a result of use of the maximum recommended topical dose, based on AUC comparisons). When administered to female rats at a dosage of 75 mg/kg/day (approximately 800 times the systemic exposure observed in human females as a result of use of the maximum recommended topical dose, 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 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 500 times the systemic exposure observed in human females as a result of use of the maximum recommended topical dose, based on AUC comparisons). No effects were observed on the viability, physical development, behavior, learning ability, or reproductive function of surviving pups. Use In Specific Populations Pregnancy Teratogenic Effects Pregnancy Category C There are no adequate and well controlled studies in pregnant women. Dapsone has been shown to have an embryocidal effect in rats and rabbits when administered orally in doses of 75 mg/kg/day and 150 mg/kg/day (approximately 800 and 500 times the systemic exposure observed in human females as a result of use of the maximum recommended topical dose, based on AUC comparisons), respectively. These effects were probably secondary to maternal toxicity. ACZONE® Gel, 5%, should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Nursing Mothers Although systemic absorption of dapsone following topical application of ACZONE® Gel, 5%, is minimal relative to oral dapsone administration, it is known that dapsone is excreted in human milk. Because of the potential for oral dapsone to cause adverse reactions in nursing infants, a decision should be made whether to discontinue nursing or to discontinue ACZONE® Gel, 5%, taking into account the importance of the drug to the mother. Pediatric Use Safety and efficacy was evaluated in 1169 children aged 12-17 years old treated with ACZONE® Gel, 5%, in the clinical studies. The adverse event rate for ACZONE® Gel, 5%, was similar to the vehicle control group. Safety and efficacy was not studied in pediatric patients less than 12 years of age, therefore ACZONE® Gel, 5%, is not recommended for use in this age group. Geriatric Use Clinical studies of ACZONE® Gel, 5%, did not include sufficient number of patients aged 65 and over to determine whether they respond differently from younger patients. G6PD Deficiency ACZONE® Gel, 5% and vehicle were evaluated in a randomized, double-blind, cross-over design clinical study of 64 patients 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. There were 56 out of 64 subjects who had a Week 2 blood draw and applied at least 50% of treatment applications. Table 3 contains results from testing of relevant hematology parameters for these two treatment periods. ACZONE® Gel was associated with a 0.32 g/dL drop in hemoglobin after two weeks of treatment, but hemoglobin levels generally returned to baseline levels at Week 12. Table 3 : Mean Hemoglobin, Bilirubin, and Reticulocyte Levels in Acne Subjects with G6PD Deficiency in ACZONE®/Vehicle Cross-Over Study ACZONE® Vehicle N Mean N Mean Hemoglobin (g/dL) Pre-treatment 53 13.44 56 13.36 2 weeks 53 13.12 55 13.34 12 weeks 50 13.42 50 13.37 Bilirubin (mg/dL) Pre-treatment 54 0.58 56 0.55 2 weeks 53 0.65 55 0.56 12 weeks 50 0.61 50 0.62 Reticulocytes (%) Pre-treatment 53 1.30 55 1.34 2 weeks 53 1.51 55 1.34 12 weeks 50 1.48 50 1.41 There were no changes from baseline in haptoglobin or lactate dehydrogenase during ACZONE® or vehicle treatment at either the 2-week or 12-week time point. The proportion of subjects who experienced decreases in hemoglobin ≥ 1 g/dL was similar between ACZONE® Gel, 5% and vehicle treatment (8 of 58 subjects had such decreases during ACZONE® treatment compared to 7 of 56 subjects during vehicle treatment among subjects with at least one on-treatment hemoglobin assessment). Subgroups based on gender, race, or G6PD enzyme activity did not display any differences in laboratory results from the overall study group. There was no evidence of clinically significant hemolytic anemia in this study. Some of these subjects developed laboratory changes suggestive of hemolysis.