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Dapsone (Systemic)

Pronunciation

Pronunciation

(DAP sone)

Index Terms

  • Diaminodiphenylsulfone

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Tablet, Oral:

Generic: 25 mg, 100 mg

Pharmacologic Category

  • Antibiotic, Miscellaneous

Pharmacology

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

Absorption

Rapid and almost complete

Distribution

Vd: 1.5 L/kg (Zuidema 1986)

Metabolism

Hepatic (acetylation and hydroxylation); forms multiple metabolites (Zuidema 1986)

Excretion

Urine (~85% as metabolites)

Time to Peak

4 to 8 hours

Half-Life Elimination

Children: 15.1 hours (Mirochnick 1993); Adults: 28 hours (range: 10 to 50 hours)

Protein Binding

Dapsone: 70% to 90%; Metabolite: ~99% (Zuidema 1986)

Use: Labeled Indications

Treatment of leprosy (due to susceptible strains of Mycobacterium leprae) and dermatitis herpetiformis

Use: Unlabeled

Prophylaxis of toxoplasmosis in severely-immunocompromised patients; alternative agent for Pneumocystis jirovecii pneumonia (PCP) prophylaxis (monotherapy) and treatment (in combination with trimethoprim); pemphigus vulgaris (oral), aphthous ulcers (severe), bullous systemic lupus erythematosus; all in consultation with patient’s physician as significant monitoring required

Contraindications

Hypersensitivity to dapsone or any component of the formulation

Dosing: Adult

Dermatitis herpetiformis: Oral: Start at 50 mg daily, increase to 300 mg daily, or higher to achieve full control, reduce to minimum maintenance dosage as soon as possible

Leprosy: Oral:

Tuberculoid (paucibacillary):

National Hansen's Disease Program: 100 mg daily in combination with rifampin for 12 months (NHDP [HRSA 2016]).

World Health Organization: 100 mg daily in combination with rifampin for 6 months (WHO 2012).

Lepromatous (multibacillary):

National Hansen's Disease Program: 100 mg daily in combination with rifampin and clofazimine for 24 months (NHDP [HRSA 2016]).

World Health Organization: 100 mg daily in combination with rifampin and clofazimine for 12 months (WHO 2012).

Aphthous ulcers, severe (off-label use): Oral:

Initial: 25 mg daily for 3 days; increase dose in increments of 25 mg daily every 3 days up to 100 mg daily for 3 days, then increase by 25 mg daily every 7 days up to 150 mg daily. Administer in 2 divided doses (75 mg dose is administered in 3 divided doses).

Maintenance: 100 to 150 mg daily in 2 divided doses with or without concomitant colchicine (Lynde 2009; Rogers 1982)

Bullous systemic lupus erythematosus (off-label use): Oral: 100 mg once daily with or without prednisone (Fabbri 2003).

Pemphigus vulgaris (off-label use): Oral: 25 mg daily for 7 days, then increase dose in increments of 25 mg daily every 7 days up to 100 mg daily for 7 days (4 weeks total therapy) with concomitant prednisone. Administer in 2 divided doses (a 75 mg dose is administered in 3 divided doses) (Azizi 2008). Note: If patient becomes lesion free, taper and discontinue gradually by decreasing dose 25 mg daily over 7 days. If no new lesions are seen, gradual taper is continued. If lesions recur, dose is increased by 25 mg daily at 7-day intervals until the patient develops no new lesions. Taper is usually ~4 weeks total.

Pneumocystis pneumonia (PCP) in HIV-infected patients (off-label use; HHS [OI adult 2015]): Oral:

Prophylaxis (primary or secondary; alternative to preferred therapy): 100 mg daily once daily or in 2 divided doses as monotherapy or 50 mg daily in combination with weekly pyrimethamine and leucovorin or 200 mg weekly in combination with weekly pyrimethamine and leucovorin

Treatment (mild to moderate disease; alternative to preferred therapy): 100 mg once daily in combination with trimethoprim for 21 days

Toxoplasma gondii encephalitis in HIV-infected patients (alternative to preferred therapy) (off-label use): Primary prophylaxis: Oral: 50 mg daily, in combination with weekly pyrimethamine and leucovorin or 200 mg weekly in combination with weekly pyrimethamine and leucovorin (HHS [OI adult 2015])

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Dermatitis herpetiformis: Infants, Children, and Adolescents: Oral: 0.5 to 2 mg/kg/day in 1 to 2 divided doses; maximum initial daily dose in adults: 50 mg/day; once lesions controlled, the dose may be decreased as tolerated for chronic therapy; usual range: 0.125 to 0.5 mg/kg/day (Ermacora 1986; Kliegman 2011)

Leprosy: Children and Adolescents: Oral:

Tuberculoid (paucibacillary):

National Hansen's Disease Program: 1 to 2 mg/kg daily (maximum daily dose: 100 mg/day) in combination with rifampin for 12 months (NHDP [HRSA 2016]; Red Book [AAP] 2015).

World Health Organization (WHO 2012):

<10 years: 2 mg/kg daily in combination with rifampin for 6 months.

≥10 years to ≤14 years: 50 mg daily in combination with rifampin for 6 months.

>14 years: Refer to adult dosing.

Lepromatous (multibacillary):

National Hansen's Disease Program: 1 mg/kg daily (maximum daily dose: 100 mg/day) in combination with rifampin and clofazimine for 24 months (NHDP [HRSA 2016]; Red Book [AAP] 2015).

World Health Organization (WHO 2012):

<10 years: 2 mg/kg daily in combination with rifampin and clofazimine for 12 months.

≥10 years to ≤14 years: 50 mg daily in combination with rifampin and clofazimine for 12 months.

>14 years: Refer to adult dosing.

Pneumocystis pneumonia (PCP) in HIV-exposed/-positive patients (off-label use): Oral:

Prophylaxis (primary or secondary; alternative to preferred therapy):

Infants and Children: 2 mg/kg/day once daily (maximum dose: 100 mg daily) or 4 mg/kg/dose once weekly (maximum dose: 200 mg) (HHS [OI pediatric] 2015)

Adolescents: Refer to adult dosing.

Treatment (mild to moderate disease; alternative to preferred therapy):

Infants and Children: 2 mg/kg/day once daily (maximum dose: 100 mg daily) in combination with trimethoprim for 21 days (HHS [OI pediatric] 2015)

Adolescents: Refer to adult dosing.

Toxoplasma gondii encephalitis in HIV-exposed/-positive patients (alternative to preferred therapy) (off-label use): Primary prophylaxis: Oral:

Infants and Children: 2 mg/kg/dose or 15 mg/m2/dose once daily (maximum daily dose: 25 mg/day), in combination with pyrimethamine and leucovorin (HHS [OI pediatric] 2015)

Adolescents (mild to moderate disease): Refer to adult dosing.

Dosing: Renal Impairment

No dosage adjustment necessary (Legendre 2012)

Dosing: Hepatic Impairment

There are no dosage adjustments provided in the manufacturer’s labeling; use with caution (Legendre 2012)

Extemporaneously Prepared

A 2 mg/mL oral suspension may be made with tablets and a 1:1 mixture of Ora-Sweet® and Ora-Plus®. Crush eight 25 mg tablets in a mortar and reduce to a fine powder. Add small portions of vehicle and mix to a uniform paste; mix while adding the vehicle in incremental proportions to almost 100 mL; transfer to a calibrated bottle, rinse mortar with vehicle, and add quantity of vehicle sufficient to make 100 mL. Label "shake well". Stable for 90 days at room temperature or refrigerated.

Jacobus Pharmaceutical Company makes a 2 mg/mL proprietary liquid formulation available under an IND for the prophylaxis of Pneumocystis jirovecii pneumonia.

Nahata MC, Morosco RS, and Trowbridge JM, "Stability of Dapsone in Two Oral Liquid Dosage Forms," Ann Pharmacother, 2000, 34(7-8):848-50.10928393

Administration

Oral: Administer with meals if GI upset occurs.

Storage

Store at 20°C to 25°C (68°F to 76°F). Protect from light.

Drug Interactions

Antimalarial Agents: May enhance the adverse/toxic effect of Dapsone (Systemic). Specifically, concomitant use of antimalarial agents with dapsone may increase the risk of hemolytic reactions. Dapsone (Systemic) may enhance the adverse/toxic effect of Antimalarial Agents. Specifically, concomitant use of dapsone with antimalarial agents may increase the risk for hemolytic reactions. Management: Closely monitor patients for signs/symptoms of hemolytic reactions with concomitant use of dapsone and antimalarial agents, particularly in patients deficient in glucose-6-phosphate dehydrogenase (G6PD), methemoglobin reductase, or with hemoglobin M. Consider therapy modification

Atazanavir: Dapsone (Systemic) may enhance the adverse/toxic effect of Atazanavir. Specifically, the risk of hyperbilirubinemia may be increased. Monitor therapy

BCG (Intravesical): Antibiotics may diminish the therapeutic effect of BCG (Intravesical). Avoid combination

BCG Vaccine (Immunization): Antibiotics may diminish the therapeutic effect of BCG Vaccine (Immunization). Monitor therapy

Bosentan: May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

Ceritinib: May increase the serum concentration of CYP2C9 Substrates. Management: Concurrent use of ceritinib with a CYP2C9 substrate that has a narrow therapeutic index (e.g., warfarin, phenytoin) should be avoided when possible. Monitor therapy

Cholera Vaccine: Antibiotics may diminish the therapeutic effect of Cholera Vaccine. Avoid combination

CYP2C9 Inducers (Strong): May increase the metabolism of CYP2C9 Substrates. Management: Consider an alternative for one of the interacting drugs. Some combinations may be specifically contraindicated. Consult appropriate manufacturer labeling. Consider therapy modification

CYP2C9 Inhibitors (Moderate): May decrease the metabolism of CYP2C9 Substrates. Monitor therapy

CYP2C9 Inhibitors (Strong): May decrease the metabolism of CYP2C9 Substrates. Consider therapy modification

CYP3A4 Inducers (Moderate): May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

CYP3A4 Inducers (Strong): May increase the metabolism of CYP3A4 Substrates. Management: Consider an alternative for one of the interacting drugs. Some combinations may be specifically contraindicated. Consult appropriate manufacturer labeling. Consider therapy modification

Dabrafenib: May decrease the serum concentration of CYP3A4 Substrates. Management: Seek alternatives to the CYP3A4 substrate when possible. If concomitant therapy cannot be avoided, monitor clinical effects of the substrate closely (particularly therapeutic effects). Consider therapy modification

Dabrafenib: May decrease the serum concentration of CYP2C9 Substrates. Management: Seek alternatives to the CYP2C9 substrate when possible. If concomitant therapy cannot be avoided, monitor clinical effects of the substrate closely (particularly therapeutic effects). Consider therapy modification

Dapsone (Topical): May enhance the adverse/toxic effect of Methemoglobinemia Associated Agents. Monitor therapy

Deferasirox: May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

Enzalutamide: May decrease the serum concentration of CYP3A4 Substrates. Management: Concurrent use of enzalutamide with CYP3A4 substrates that have a narrow therapeutic index should be avoided. Use of enzalutamide and any other CYP3A4 substrate should be performed with caution and close monitoring. Consider therapy modification

Enzalutamide: May decrease the serum concentration of CYP2C9 Substrates. Management: Concurrent use of enzalutamide with CYP2C9 substrates that have a narrow therapeutic index should be avoided. Use of enzalutamide and any other CYP2C9 substrate should be performed with caution and close monitoring. Consider therapy modification

Lactobacillus and Estriol: Antibiotics may diminish the therapeutic effect of Lactobacillus and Estriol. Monitor therapy

MiFEPRIStone: May increase the serum concentration of CYP2C9 Substrates. Management: Use CYP2C9 substrates at the lowest recommended dose, and monitor closely for adverse effects, during and in the 2 weeks following mifepristone treatment. Consider therapy modification

Mitotane: May decrease the serum concentration of CYP3A4 Substrates. Management: Doses of CYP3A4 substrates may need to be adjusted substantially when used in patients being treated with mitotane. Consider therapy modification

Nitric Oxide: May enhance the adverse/toxic effect of Methemoglobinemia Associated Agents. Combinations of these agents may increase the likelihood of significant methemoglobinemia. Management: Monitor patients for signs of methemoglobinemia (e.g., hypoxia, cyanosis) when nitric oxide is used in combination with other agents associated with development of methemoglobinemia. Avoid lidocaine/prilocaine. Monitor therapy

Prilocaine: Methemoglobinemia Associated Agents may enhance the adverse/toxic effect of Prilocaine. Combinations of these agents may increase the likelihood of significant methemoglobinemia. Management: Monitor patients for signs of methemoglobinemia (e.g., hypoxia, cyanosis) when prilocaine is used in combination with other agents associated with development of methemoglobinemia. Avoid lidocaine/prilocaine in infants receiving such agents. Monitor therapy

Probenecid: May increase the serum concentration of Dapsone (Systemic). Monitor therapy

Rifamycin Derivatives: May increase the metabolism of Dapsone (Systemic). Consider therapy modification

Siltuximab: May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

Sodium Nitrite: Methemoglobinemia Associated Agents may enhance the adverse/toxic effect of Sodium Nitrite. Combinations of these agents may increase the likelihood of significant methemoglobinemia. Monitor therapy

Sodium Picosulfate: Antibiotics may diminish the therapeutic effect of Sodium Picosulfate. Management: Consider using an alternative product for bowel cleansing prior to a colonoscopy in patients who have recently used or are concurrently using an antibiotic. Consider therapy modification

St John's Wort: May decrease the serum concentration of CYP3A4 Substrates. Management: Consider an alternative for one of the interacting drugs. Some combinations may be specifically contraindicated. Consult appropriate manufacturer labeling. Consider therapy modification

Tetracaine (Topical): May enhance the adverse/toxic effect of Methemoglobinemia Associated Agents. Monitor therapy

Tocilizumab: May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

Trimethoprim: May increase the serum concentration of Dapsone (Systemic). Dapsone (Systemic) may increase the serum concentration of Trimethoprim. Monitor therapy

Typhoid Vaccine: Antibiotics may diminish the therapeutic effect of Typhoid Vaccine. Only the live attenuated Ty21a strain is affected. Management: Vaccination with live attenuated typhoid vaccine (Ty21a) should be avoided in patients being treated with systemic antibacterial agents. Use of this vaccine should be postponed until at least 3 days after cessation of antibacterial agents. Consider therapy modification

Adverse Reactions

Frequency not always defined.

>10%: Hematologic: Reticulocyte increase (2% to 12%), hemolysis (>10%; dose related; seen in patients with and without G6PD deficiency), hemoglobin decrease (>10%; 1-2 g/dL; almost all patients), methemoglobinemia (>10%), red cell life span shortened (>10%), Agranulocytosis, anemia, leukopenia, pure red cell aplasia (case report)

Cardiovascular: Tachycardia

Central nervous system: Fever, headache, insomnia, psychosis, vertigo

Dermatologic: Bullous and exfoliative dermatitis, erythema nodosum, exfoliative dermatitis, morbilliform and scarlatiniform reactions, phototoxicity, Stevens-Johnson syndrome, toxic epidermal necrolysis, urticaria

Endocrine & metabolic: Hypoalbuminemia (without proteinuria), male infertility

Gastrointestinal: Abdominal pain, nausea, pancreatitis, vomiting

Hepatic: Cholestatic jaundice, hepatitis

Neuromuscular & skeletal: Drug-induced lupus erythematosus, lower motor neuron toxicity (prolonged therapy), peripheral neuropathy (rare, nonleprosy patients)

Ocular: Blurred vision

Otic: Tinnitus

Renal: Albuminuria, nephrotic syndrome, renal papillary necrosis

Respiratory: Interstitial pneumonitis, pulmonary eosinophilia

Miscellaneous: Infectious mononucleosis-like syndrome (rash, fever, lymphadenopathy, hepatic dysfunction)

Warnings/Precautions

Concerns related to adverse effects:

• Blood dyscrasias: Aplastic anemia, agranulocytosis and other severe blood dyscrasias (some fatal) have been reported; monitor for signs/symptoms (eg, fever, sore throat, pallor, purpura, jaundice). Closely monitor CBC and discontinue therapy if a significant reduction in leukocytes, platelets, or hemopoiesis is seen.

• Dermatologic reactions: Serious dermatologic reactions, including toxic erythema, erythema multiforme, toxic epidermal necrolysis, morbilliform and scarlatiniform reactions, urticaria, and erythema nodosum have been reported rarely. Discontinue therapy if new or severe dermatologic reactions occur; leprosy reactional states (eg, erythema nodosum leprosum) do not require discontinuation.

• Hepatic effects: Toxic hepatitis and cholestatic jaundice have been reported; hyperbilirubinemia may occur more frequently in G6PD deficient patients. Monitor liver function; discontinue use if abnormalities occur.

• Peripheral neuropathy: Motor loss and muscle weakness have been reported; discontinue use if symptoms of peripheral neuropathy develop. Recovery after discontinuation is usually complete; some patients may tolerate retreatment at reduced doses.

• Sulfonamide allergy: Use with caution in patients with hypersensitivity to other sulfonamides; sulfone reactions may also occur as potentially fatal hypersensitivity reactions, requiring drug discontinuation.

• Superinfection: Prolonged use may result in fungal or bacterial superinfection, including C. difficile-associated diarrhea and pseudomembranous colitis; CDAD has been observed >2 months postantibiotic treatment.

Disease-related concerns:

• Anemia: Use with caution in patients with severe anemia; treat prior to therapy.

Concurrent drug therapy issues:

• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.

Special populations:

• G6PD deficiency: Use with caution in patients with G6PD deficiency; dose-related hemolysis and methemoglobinemia may occur.

• Hemoglobin M deficiency: Use with caution in patients with hemoglobin M deficiency.

• Methemoglobin reductase deficiency: Use with caution in patients with methemoglobin reductase deficiency.

Monitoring Parameters

Check G6PD levels (prior to initiation); CBC (weekly for first month, monthly for 6 months and semiannually thereafter); reticulocyte counts; liver function tests (baseline and periodic). Monitor patients for signs of jaundice, hemolysis, and blood dyscrasias.

Pregnancy Risk Factor

C

Pregnancy Considerations

Dapsone crosses the placenta (Brabin 2004). Per the manufacturer, dapsone has not shown an increased risk of congenital anomalies when given during all trimesters of pregnancy. Several reports have described adverse effects in the newborn after in utero exposure to dapsone, including neonatal hemolytic disease, methemoglobinemia, and hyperbilirubinemia (Hocking 1968; Kabra 1998; Thornton 1989). Dapsone may be used in pregnant women requiring maintenance therapy of either leprosy or dermatitis herpetiformis. Dapsone may be used as an alternative agent for management of Pneumocystis jirovecii pneumonia (PCP) or Toxoplasma gondii encephalitis in pregnant, HIV-infected patients (HHS [OI adult] 2015). Because of the theoretical increased risk for hyperbilirubinemia and kernicterus, neonatal care providers should be informed if maternal dapsone is used near term (HHS [OI adult] 2015).

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Patient may experience nausea, vomiting, headache, abdominal pain, or insomnia. Have patient report immediately to prescriber signs of infection, signs of liver problems (dark urine, fatigue, lack of appetite, nausea, abdominal pain, light-colored stools, vomiting, or jaundice), signs of lupus (rash on the cheeks or other body parts, sunburn easy, muscle or joint pain, angina or shortness of breath, or swelling in the arms or legs), signs of pancreatitis (severe abdominal pain, severe back pain, severe nausea, or vomiting), severe loss of strength and energy, burning or numbness feeling, muscle weakness, slow movements, blurred vision, tinnitus, mood changes, urinary retention, change in amount of urine passed, bruising, bleeding, pale skin, tachycardia, purple spots or redness of skin, or signs of Stevens-Johnson syndrome/toxic epidermal necrolysis (red, swollen, blistered, or peeling skin [with or without fever]; red or irritated eyes; or sores in mouth, throat, nose, or eyes) (HCAHPS).

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for health care professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience, and judgment in diagnosing, treating, and advising patients.

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