dapsone (Avlosulfon)
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Introduction
Tradename: Avlosulfon.
Indications
- dermatitis herpetiformis
- pyoderma gangrenosum[7]
- subcorneal pustular dermatosis
- pemphigoid
- granuloma annulare
- connective tissue disease
- vasculitis
- leprosy
- Pneumocystis carinii pneumonia
- mycetoma[7]
- Toxoplasmosis[7]
- topical treatment of acne vulgaris[6]
- chronic idiopathic urticaria & autoimmune urticaria (2nd line)[9]
Contraindications
Caution:
- patients with severe anemia
- glucose-6-phosphate dehydrogenase activity
Dosage
- dermatitis herpetiformis: 50-300 mg PO QD
- leprosy: 50-100 mg/day for 3-10 years
- Pneumocystis carinii pneumonia
- prophylaxis: 100 mg PO QD
- treatment: 100 mg PO QD in combination with trimethoprim 20 mg/kg/day for 21 days
Tabs: 25 & 100 mg. Aczone: topical gel for acne
Dosage adjustment in renal failure
- dose adjustment may be necessary with renal impairment.
- no specific guidelines available
Pharmacokinetics
- well absorbed following oral administration
- metabolized in the liver by cyt P450 3A4
- 1/2life 20-30 hours
- elimination
- 20% unchanged in the urine
- 70-85% as metabolites in the urine
elimination via liver
elimination via kidney
1/2life = 20-30 hours
Monitor
- G6PD in erythrocytes to rule out G6PD deficiency
- not necessary with topical dapsone
- screening for HLA-B*1301 allele recommended prior to dapsone therapy in Asians[8]
Adverse effects
- not common (1-10%)
- dose related hemolysis in patients with & without G6PD deficiency
- methemoglobinemia with cyanosis
- uncommon (< 1%)
- adverse cutaneous reaction in Asians with HLA-B*1301 allele[8]
Drug interactions
- rifampin lowers blood levels of dapsone by increasing clearance
- folate antagonists such as pyrimethamine may increase likelihood of hematologic reactions
- PABA may decrease effectiveness
- didanosine (ddI) in combination decreases effect of dapsone; administer 2 hours apart
- trimethoprim in combination may increase both dapsone & trimethoprim levels
- clofazimine in combination may decrease effective of dapsone
- any drug that inhibits cyt P450 3A4 may increase levels of dapsone
- any drug that induces cyt P450 3A4 may diminish levels of dapsone
- drug interaction(s) anticonvulsants with anti-bacterial agents
- drug interaction(s) of antibiotics with warfarin
Mechanism of action
- competitive antagonist of para-aminobenzoic acid (PABA)
- prevents bacterial utilization of PABA for synthesis of folate
More general terms
More specific terms
Additional terms
- cytochrome P450 3A4 (cytochrome P450 C3, nifedipine oxidase, P450-PCN1, NF-25, CYP3A4)
- dermatitis herpetiformis; Duhring-Brocq disease
- leprosy (Hansen's disease)
- para-aminobenzoic acid; 4-aminobenzoic acid (PABA, Paraben, Potaba)
References
- ↑ The Pharmacological Basis of Therapeutics, 9th ed. Gilman et al, eds. Permagon Press/McGraw Hill, 1996
- ↑ Drug Information & Medication Formulary, Veterans Affairs, Central California Health Care System, 1st ed., Ravnan et al eds, 1998
- ↑ Kaiser Permanente Northern California Regional Drug Formulary, 1998
- ↑ Medical Knowledge Self Assessment Program (MKSAP) 11, 18. American College of Physicians, Philadelphia 1998, 2018
- ↑ Prescriber's Letter 13(2): 2006 Detail-Document#: http://prescribersletter.com/(5bhgn1a4ni4cyp2tvybwfh55)/pl/ArticleDD.aspx?li=1&st=1&cs=&s=PRL&pt=3&fpt=25&dd=220215&pb=PRL (subscription needed) http://www.prescribersletter.com
- ↑ 6.0 6.1 Prescriber's Letter 16(1): 2009 COMMENTARY: New Drug: Aczone (Dapsone) Gel 5% GUIDELINES: Acne Vulgaris Management GUIDELINES: Recommendations for Acne Management Detail-Document#: http://prescribersletter.com/(5bhgn1a4ni4cyp2tvybwfh55)/pl/ArticleDD.aspx?li=1&st=1&cs=&s=PRL&pt=3&fpt=25&dd=250112&pb=PRL (subscription needed) http://www.prescribersletter.com
- ↑ 7.0 7.1 7.2 7.3 7.4 Deprecated Reference
- ↑ 8.0 8.1 8.2 Tangamornsuksan W, Lohitnavy M. Association Between HLA-B*1301 and Dapsone-Induced Cutaneous Adverse Drug Reactions. A Systematic Review and Meta-analysis. JAMA Dermatol. 2018 Mar 14. PMID: https://www.ncbi.nlm.nih.gov/pubmed/29541744
- ↑ 9.0 9.1 Liang SE, Hoffmann R, Peterson E et al. Use of dapsone in the treatment of chronic idiopathic and autoimmune urticaria. JAMA Dermatol 2018 Nov 21; 155:90. PMID: https://www.ncbi.nlm.nih.gov/pubmed/30476976 https://jamanetwork.com/journals/jamadermatology/fullarticle/2715087