Trade Names:Aczone- Gel 5%
Trade Names:Dapsone- Tablets 25 mg- Tablets 100 mg
Mechanism of action is unknown; however, dapsone is bactericidal and bacteriostatic against Mycobacterium leprae .
Rapidly and nearly completely absorbed from the GI tract, reaching peak plasma concentrations in 4 to 8 h. Administration of 200 mg/day for 8 days achieves plateau levels of 0.1 to 7 mcg/mL.
Approximately 70% to 90% bound to plasma protein. The main metabolite, monoacetyl dapsone, is nearly 100% protein bound.
Dapsone is acetylated in the liver, the degree of which is genetically determined.
The plasma t ½ ranges from 10 to 50 h. Approximately 70% to 85% is excreted in the urine as conjugates and unidentified metabolites. Enterohepatic circulation accounts for appreciable tissue levels 3 wk after discontinuation of therapy.
Treatment of dermatitis herpetiformis; leprosy.Topical
Treatment of acne vulgaris.
Topical Apply an approximately pea-sized amount in a thin layer to the acne-affected areas twice daily. Rub in gently and completely.Dermatitis HerpetiformisAdults and Children
PO Start with 50 mg/day in adults and correspondingly smaller doses in children. If full control is not achieved with 50 to 300 mg/day, higher doses may be tried. Reduce dose to minimum maintenance level as soon as possible. The time for dosage reduction is 8 mo (range, 4 mo to 2½ yr of age) and, for dosage elimination, 29 mo (range, 6 mo to 9 yr of age).LeprosyAdults and Children
PO 100 mg/day in adults and correspondingly smaller doses in children without interruption in therapy with at least 1 antileprosy drug.
Store tablets at 68° to 77°F. Protect from light.Topical
Store gel at 59° to 86°F. Protect from freezing.
Absorption of dapsone may be decreased, resulting in a loss of efficacy.Folic acid antagonists (eg, pyrimethamine)
Risk of hematologic reactions may be increased.Rifampin
Dapsone levels may be reduced 7- to 10-fold.Topical benzoyl peroxide
Topical application of dapsone followed by topical benzoyl peroxide may cause temporary local yellow or orange discoloration of the skin and facial hair.Trimethoprim
Plasma concentrations of both dapsone and trimethoprim may be elevated, increasing the pharmacologic and toxic effects.
None well documented.
Headache, insomnia, peripheral neuropathy, psychosis, vertigo.Topical
Headache (4%); pyrexia (1%); suicide attempt, tonic-clonic movements.
Bullous and exfoliative dermatitis, erythema multiforme, erythema nodosum, morbilliform and scarlatiniform reactions, phototoxicity, toxic epidermal necrolysis (TEN), urticaria.Topical
Application-site reaction (18%); dryness (16%); erythema, oiliness/peeling (13%); burning, pruritus (1%).
Blurred vision, tinnitus.Topical
Nasopharyngitis (5%); pharyngitis (2%); severe pharyngitis.
Abdominal pain, nausea, pancreatitis, vomiting.Topical
Abdominal pain, pancreatitis, severe vomiting.
Albuminuria, male infertility, nephrotoxic syndrome, renal papillary necrosis.
Agranulocytosis, hemolysis, hemolytic anemia.
Joint spasm (1%).
Upper respiratory tract infection (3%); cough, sinusitis (2%).
Fever, hypoalbuminemia without proteinuria, infectious mononucleosis–like syndrome, lupus erythematosus.Topical
Ensure that CBC and differential are performed and evaluated prior to starting therapy, weekly for the first month of therapy, then monthly for 6 mo, and every 6 mo thereafter during treatment.
Category C .
Excreted in breast milk.Topical
Children 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 and functional development of children.Topical
Safety and efficacy not established in children younger than 12 yr of age.
Serious cutaneous reactions (eg, erythema multiforme, TEN) resulting from hypersensitivity may occur. In addition, sulfone syndrome, a potentially fatal hypersensitivity with symptoms of exfoliative dermatitis, fever, hemolytic anemia, jaundice with hepatic necrosis, lymphadenopathy, malaise, and methemoglobinemia, may occur.
Toxic hepatitis or cholestatic jaundice have been reported and hyperbilirubinemia may occur more frequently in patients with glucose-6-phosphate dehydrogenase (G-6-PD) deficiency.
Deaths caused by agranulocytosis, aplastic anemia, and other blood dyscrasias have occurred. Treat severe anemia prior to initiation of dapsone therapy.
Because hemolysis and Heinz body formation may be exaggerated in individuals with G-6-PD deficiency, hemoglobin M, or methemoglobin reductase deficiency, give dapsone with caution to patients with these conditions or patients exposed to other agents or with conditions capable of producing hemolysis (eg, diabetic ketosis).
Has been reported with oral treatment.
Hyperexcitability, methemoglobin-induced depression, nausea, seizures or severe cyanosis, severe anoxia (with retinal and optic nerve damage), vomiting.
Copyright © 2009 Wolters Kluwer Health.