dapsone 100 MG Oral Tablet

INDICATIONS AND USAGE ACZONE ® (dapsone) Gel, 7.5%, is indicated for the topical treatment of acne vulgaris in patients 9 years of age and older. ACZONE ® Gel, 7.5%, is a sulfone indicated for the topical treatment of acne vulgaris in patients 9 years of age and older ( 1 ).

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 to 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 Clofazimine 50 to 100 mg daily or Ethionamide 250 to 500 mg daily. Dapsone 100 mg daily is continued 3 to 10 years until all signs of clinical activity are controlled with skin scrapings and biopsies are 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 to 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, anti-leprosy treatment is continued. Analgesics, steroids, and other agents available from USPHS, Carville, LA, are used to suppress the reaction.

WARNINGS AND PRECAUTIONS Methemoglobinemia: Cases of methemoglobinemia have been reported. Discontinue dapsone gel if signs of methemoglobinemia occur ( 5.1 ). Hemolysis: Some patients with Glucose-6-phosphate Dehydrogenase (G6PD) deficiency using topical dapsone developed laboratory changes suggestive of hemolysis ( 5.1 ) ( 8.6 ). 5.1 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 dapsone 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 dapsone 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 ( 7.4 )] . He molysis 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. 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 ( 8.6 )]. Discontinue dapsone gel, 7.5%, if signs and symptoms suggestive of hemolytic anemia occur. Avoid use of dapsone gel, 7.5% in patients who are taking oral dapsone or antimalarial medications because of the potential for hemolytic reactions. Combination of dapsone gel, 7.5%, with trimethoprim/sulfamethoxazole (TMP/SMX) may increase the likelihood of hemolysis in patients with G6PD deficiency [see Drug Interactions ( 7.1 )] . 5.2 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. 5.3 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.

CONTRAINDICATIONS Hypersensitivity to Dapsone and/or its derivatives.

CLINICAL PHARMACOLOGY 12.1 Mechanism of Action The mechanism of action of dapsone gel in treating acne vulgaris is not known. 12.3 Pharmacokinetics In a pharmacokinetic study, male and female subjects 16 years of age or older with acne vulgaris (N=19) applied 2 grams of dapsone gel, 7.5% to the face, upper chest, upper back and shoulders once daily for 28 days. Steady state for dapsone was reached within 7 days of dosing. On Day 28, the mean dapsone maximum plasma concentration (Cmax) and area under the concentration-time curve from 0 to 24 hours post dose (AUC 0 to 24h ) were 13.0 ± 6.8 ng/mL and 282 ± 146 ng∙h/mL, respectively. The systemic exposure from dapsone gel, 7.5% is expected to be about 1% of that from a 100 mg oral dose. Long-term safety studies were not conducted with dapsone gel, 7.5%, however, in a long-term clinical study of dapsone gel, 5% treatment (twice daily), periodic blood samples were collected up to 12 months to determine systemic exposure of dapsone and its metabolites in approximately 500 subjects. Based on the measurable dapsone concentrations from 408 subjects (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 to 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 subjects. In an open label safety and pharmacokinetic study in pediatric subjects 9 to 11 years of age with acne vulgaris, a subset of subjects (N = 16) received once daily topical application of approximately 2 grams of dapsone gel, 7.5%, to the entire face, shoulders, upper chest and upper back for 8 days. On Day 8, the systemic concentrations were at or near steady state and the mean ± SD systemic concentration of dapsone at 10 hours post dose was 20 ± 12.5 ng/mL. 12.4 Microbiology In Vivo Activity : No microbiology or immunology studies were conducted during dapsone gel, 7.5% clinical studies. Drug Resistance : No dapsone resistance studies were conducted during dapsone gel clinical studies therefore there are no data available as to whether dapsone treatment may have resulted in decreased susceptibility of Propionibacterium acnes , an organism associated with acne, or 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.