Dapsone

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.

• Dermatitis herpetiformis: (D.H.) Leprosy: All forms of leprosy except for cases of proven Dapsone resistance.

• Hypersensitivity to Dapsone and/or its derivatives.contraindicated

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 1/2 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.

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 coadministered 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.

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 to 2g of hemoglobin, an increase in the reticulocytes (2 to 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.

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.

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 to 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 to 5 mg/kg every 4 to 6 hours. Methylene blue reduction depends on G6PD and should not be given to fully expressed G6PD deficient patients.

• Jul 3, 1979ANDAANDA086841Everest Life Sci
• Jul 3, 1979ANDAANDA086842Everest Life Sci
• Jul 7, 2005NDANDA021794Almirall
• Feb 24, 2016NDANDA207154Almirall
• May 6, 2016ANDAANDA203887Solis Pharms
• May 10, 2016ANDAANDA204074Chartwell Rx
• Dec 1, 2016ANDAANDA206505Novitium Pharma
• Oct 16, 2017ANDAANDA209506Sun Pharma Canada

Reference statistics from the openFDA drug-shortage dataset. For a live view, consult the FDA database directly. Not clinical guidance.

• Dapsone, Gel, 7.5% (NDC 69238-1627-6)To be discontinued
  Sponsor: Amneal Pharmaceuticals
  Updated Mar 27, 2026

1. 1Off Label Use1,19011%
2. 2Drug Ineffective1,12911%
3. 3Nausea4794.6%
4. 4Methaemoglobinaemia4694.5%
5. 5Fatigue4654.5%
6. 6Pyrexia4574.4%
7. 7Diarrhoea4184.0%
8. 8Rash3893.7%
9. 9Pneumonia3823.7%
10. 10Dyspnoea3813.7%
11. 11Pain3683.5%
12. 12Anaemia3553.4%
13. 13Condition Aggravated3473.3%
14. 14Drug Reaction With Eosinophilia And Systemic Symptoms3433.3%
15. 15Treatment Failure3413.3%

Recent PubMed references pinned to Dapsone as a MeSH major topic. Citations link to pubmed.ncbi.nlm.nih.gov.

• Dapsone and schistocytes: Thrombotic microangiopathy or not?
  PloS one · 2026 · Archambeaud A, Aumont C, Pouplard C, et al.
  PMID 42172240DOI 10.1371/journal.pone.0349570
• Dapsone-induced methaemoglobinaemia: a challenging diagnosis or missed opportunity? Exploring human factors in the diagnostic process.
  BMJ case reports · 2026 · Sanderson J, Albon L
  PMID 42055748DOI 10.1136/bcr-2025-271307
• Outcomes of alternative therapy in HLA-B* 13:01 positive leprosy patients without dapsone versus standard MDT in negative patients: A comparative effectiveness study.
  PLoS neglected tropical diseases · 2026 · Li Y, Wang Z, Chu T, et al.
  PMID 41843636DOI 10.1371/journal.pntd.0014114
• Dapsone response in immune thrombocytopenic purpura is associated with dapsone dose and mediated through reduction in haemoglobin: A longitudinal data analysis of 58 adult and paediatric ITP patients demonstrates efficacy and safety.
  British journal of haematology · 2026 · Shah SD, Vibhakar A, Shah RP, et al.
  PMID 41802829DOI 10.1111/bjh.70414
• Clinico-Epidemiological and Molecular Evidences for Reactivation of Herpesviruses in Dapsone-Induced Hypersensitivity Reactions in Nepalese Leprosy Patients: An Observational Study.
  Immunity, inflammation and disease · 2026 · Rana DR, Shakya J, Baral S, et al.
  PMID 41738358DOI 10.1002/iid3.70385
• Persistent methaemoglobinaemia due to unsupervised use of topical dapsone-adapalene.
  BMJ case reports · 2026 · Joshi S, Rao P, Achari P, et al.
  PMID 41667210DOI 10.1136/bcr-2025-271194
• Methemoglobinemia induced by dapsone, hydroxychloroquine, and rifampin combination for post-treatment Lyme disease syndrome: A case report.
  Journal of the American Pharmacists Association : JAPhA · 2026 · Worden J, Baumeister T, Stogner S, et al.
  PMID 41421419DOI 10.1016/j.japh.2025.103009
• Efficacy and safety of dapsone in adult immune thrombocytopenia: a systematic review and meta-analysis.
  European journal of medical research · 2025 · Khan I, Qasim SA, Rath S, et al.
  PMID 41382219DOI 10.1186/s40001-025-03427-0

The 10 most recently updated of 81 ClinicalTrials.gov registrations naming Dapsone as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

• Randomized, Triple-Blind, Vehicle-Controlled Trial of Topical Dapsone Gel 7.5% in Patients With Acne Vulgaris
  Completed · Phase 4 · Interventional · 100 enrolled · Oya Helin Dundar
  NCT07244887updated 2026-05-22
• Precision Medicine Approach for Early Dementia & Mild Cognitive Impairment
  Completed · Phase 3 · Interventional · 73 enrolled · Alzheimer's Prevention and Reversal Project, Inc.
  NCT05894954updated 2026-02-18
• A Randomized Multicenter Study for Isolated Skin Vasculitis
  Recruiting · Phase 2 · Interventional · 90 enrolled · University of Pennsylvania
  NCT02939573updated 2026-01-23
• Efficacy and Safety of add-on Dapsone Versus add-on Methotrexate in Patients With Bullous Pemphigoid
  Completed · Phase 4 · Interventional · 62 enrolled · All India Institute of Medical Sciences, Bhubaneswar
  NCT05984381updated 2025-08-14
• Chlorproguanil-Dapsone in Pregnant Women
  Terminated · Phase 1 · Interventional · 132 enrolled · Centers for Disease Control and Prevention
  NCT00126971updated 2025-04-20
• Rab 32 Gene Polymorphisms as a Prognostic Factor in Leprosy Patients
  Recruiting · Interventional · 50 enrolled · South Valley University
  NCT06819449updated 2025-02-11
• Dermatitis Herpetiformis Refractory to Gluten Free Diet
  Enrolling by invitation · Observational · 23 enrolled · Tampere University Hospital
  NCT05998291updated 2023-08-22
• Comparison of the Efficacy of Clindamycin Phosphate 1% Gel Versus Once-daily Dapsone 5% Gel in the Treatment of Moderate Acne Vulgaris
  Completed · Phase 2 · Interventional · 100 enrolled · Jinnah Postgraduate Medical Centre
  NCT05926869updated 2023-07-03
• Effect of New Topical Preparation for Treatment of Acne Vulgaris
  Unknown · Phase 2 · Interventional · 20 enrolled · Mansoura University
  NCT05899699updated 2023-06-13
• Aczone Gel 7.5% in the Treatment of Acne Vulgaris in Patients With Skin of Color
  Completed · Phase 4 · Interventional · 20 enrolled · Icahn School of Medicine at Mount Sinai
  NCT03681470updated 2022-07-27

CPIC-curated drug–gene pairs for Dapsone. Levels describe the strength of curated evidence and guideline status — never a recommendation to test or to adjust therapy.

• G6PDCPIC AClinPGx 4FDA label: Actionable PGx
  G6PD
• HLA-BCPIC C (provisional)ClinPGx 2A

Frequently asked questions

How does Dapsone work?

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.

What is Dapsone used for?

According to FDA labeling, Dapsone carries indications including: Dermatitis herpetiformis: (D.H.) Leprosy: All forms of leprosy except for cases of proven Dapsone resistance.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.

What class of drug is Dapsone?

Dapsone is classified as Drugs for treatment of lepra, Other anti-acne preparations for topical use, Sulfone, Para-Aminobenzoic Acid Inhibitors, Cellular Synthetic Activity Alteration, Decreased Folic Acid Modification.

What are the brand names for Dapsone?

Dapsone is marketed under brand names including Aczone.

What are the contraindications for Dapsone?

Dapsone labeling lists contraindications including: Hypersensitivity to Dapsone and/or its derivatives.. Always consult the full prescribing information and a clinician.