No

Antibiotic, Miscellaneous

Treatment of leprosy and dermatitis herpetiformis (infections caused by Mycobacterium leprae)

May be useful in relapsing polychondritis, prophylaxis of malaria, inflammatory bowel disorders, Leishmaniasis, rheumatic/connective tissue disorders, brown recluse spider bites

C

Hypersensitivity to dapsone or any component

Use with caution in patients with severe anemia, G-6-PD, methemoglobin reductase or hemoglobin M deficiency; hypersensitivity to other sulfonamides; aplastic anemia, agranulocytosis and other severe blood dyscrasias have resulted in death; monitor carefully; treat severe anemia prior to therapy; serious dermatologic reactions (including toxic epidermal necrolysis) are rare but potential occurrences; sulfone reactions may also occur as potentially fatal hypersensitivity reactions; these, but not leprosy reactional states, require drug discontinuation; dapsone is carcinogenic in small animals

1% to 10%: Hematologic: Hemolysis, methemoglobinemia

<1%: Reactional states (ie, abrupt changes in clinical activity occurring during any leprosy treatment; classified as reversal of erythema nodosum leprosum reactions); insomnia, headache, exfoliative dermatitis, photosensitivity, nausea, vomiting, anemia, leukopenia, agranulocytosis, hepatitis, cholestatic jaundice, peripheral neuropathy (usually in nonleprosy patients), blurred vision, tinnitus, SLE

Symptoms of overdose include nausea, vomiting, confusion, hyperexcitability, seizures, cyanosis, hemolysis, methemoglobinemia, sulfhemoglobinemia, metabolic acidosis, hallucinations, hepatitis

Following decontamination, methylene blue 1-2 mg/kg I.V. is treatment of choice if MHb level is >15%; may repeat every 6-8 hours for 2-3 days if needed; if hemolysis is present, give I.V. fluids and alkalinize urine to prevent acute tubular necrosis

CYP2C9, 2E1, and 3A3/4 enzyme substrate

Increased toxicity: Folic acid antagonists may increase the risk of hematologic reactions of dapsone; probenecid decreases dapsone excretion; trimethoprim with dapsone may increase toxic effects of both drugs; Protease inhibitor like amprenavir and ritonavir may increase dapsone's serum concentration.

Protect from light

Competitive antagonist of para-aminobenzoic acid (PABA) and prevents normal bacterial utilization of PABA for the synthesis of folic acid

Absorption: Oral: Well absorbed

Distribution: V_d: 1.5 L/kg; throughout total body water and present in all tissues, especially liver and kidney

Metabolism: In the liver

Half-life, elimination: 30 hours (range: 10-50 hours)

Elimination: In urine

Oral:

Children: 1-2 mg/kg/24 hours, up to a maximum of 100 mg/day

Adults: 50-100 mg/day for 3-10 years

Dermatitis herpetiformis: Adults: Start at 50 mg/day, increase to 300 mg/day, or higher to achieve full control, reduce dosage to minimum level as soon as possible

Prophylaxis of Pneumocystis carinii pneumonia:

Children >1 month: 1 mg/kg/day; maximum: 100 mg

Adults: 100 mg/day

Treatment of Pneumocystis carinii pneumonia: Adults: 100 mg/day in combination with trimethoprim (15-20 mg/kg/day) for 21 days

Dosing in renal impairment: No specific guidelines are available

Do not administer with antacids, alkaline foods or drugs (may decrease dapsone absorption)

Monitor patient for signs of jaundice and hemolysis; CBC weekly for first month, monthly for 6 months, and semiannually thereafter

May cause insomnia

None reported

No information available to require special precautions

No effects or complications reported

Take as directed, for full term of therapy (treatment for leprosy may take 3-10 years). Do not take with antacids, alkaline foods, or drugs (may decrease dapsone absorption). Frequent blood tests may be required during therapy. Discontinue if rash develops and notify prescriber. Report persistent sore throat, fever, chills; constant fatigue; yellowing of skin or eyes; or easy bruising or bleeding. Pregnancy/breast-feeding precautions: Inform prescriber if you are or intend to be pregnant. Breast-feeding is not recommended.

Tablet: 25 mg, 100 mg

One report indicated that dapsone may not be well absorbed when administered to children as suspensions made from pulverized tablets

Jacobus Pharmaceutical Company (609) 921-7447 makes a 2 mg/mL proprietary liquid formulation available under an IND for the prophylaxis of Pneumocystis carinii pneumonia

"1997 USPHS/IDSA Guidelines for the Prevention of Opportunistic Infections in Persons Infected With Human Immunodeficiency Virus. USPHS/IDSA Prevention of Opportunistic Infections Working Group," MMWR Morb Mortal Wkly Rep, 1997, 46(RR-12): 1-46.

Barnett ED, Pelton SI, Mirochnick M, et al, "Dapsone for Prevention of Pneumocystis Pneumonia in Children With Acquired Immunodeficiency Syndrome," Pediatr Infect Dis J, 1994, 13(1):72-4.

El-Sadr WM, Murphy RL, Yurik TM, et al, "Atovaquone Compared With Dapsone for the Prevention of Pneumocystic carinii in Patients With HIV Infection Who Cannot Tolerate Trimethoprim, Sulfonamides, or Both," N Engl J Med, 1998, 339(26):1889-95.

Hansen DG, Challoner KR, and Smith DE, "Dapsone Intoxication: Two Case Reports," J Emerg Med, 1994, 12(3):347-51.

McGoldrick MD and Bailie GR, "Severe Accidental Dapsone Overdose," Am J Emerg Med, 1995, 13(4):414-5.

Medina I, Mills J, Leoung G, et al, "Oral Therapy for Pneumocystis carinii Pneumonia in the Acquired Immunodeficiency Syndrome. A Controlled Trial of Trimethoprim-Sulfamethoxazole Versus Trimethoprim-Dapsone," N Engl J Med, 1990, 323(12):776-82.

Meier K, "Dapsone," Poisoning and Drug Overdose, 2nd ed, Olson KR, ed, East Norwalk, CT: Appleton and Lange, 1994, 150-2.

Mirochnick M, Michaels M, Clarke D, et al, "Pharmacokinetics of Dapsone in Children," J Pediatr, 1993, 122(5 Pt 1):806-9.

Stavola JJ and Noel GJ, "Efficacy and Safety of Dapsone Prophylaxis Against Pneumocystis carinii Pneumonia in Human Immunodeficiency Virus-Infected Children," Pediatr Infect Dis J, 1993, 12(8):644-7.

Tracqui A, Gutbub AM, Kintz P, et al, "A Case of Acute Dapsone Poisoning: Toxicological Data and Review of the Literature," J Anal Toxicol, 1995, 19(4):229-35.

Wynn RF, Laing RB, and Leen CL, "Case Report of Dapsone-Related Thrombocytosis in an AIDS Patient," Am J Med, 1995, 98(6):602.