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 (Ref).
Bullous pemphigoid (alternative agent) (off-label use): Oral: 1 to 1.5 mg/kg/day, with or without immunosuppressive therapy (Ref).
Bullous systemic lupus erythematosus (off-label use): Oral: 50 mg once daily initially, with or without immunosuppressive therapy; range 25 to 200 mg daily (Ref).
Dermatitis herpetiformis (adjunctive agent):
Note: Management involves a combination of a strict lifelong gluten-free diet and drug therapy (Ref).
Oral: Initial: 25 to 50 mg daily; may increase as needed to 100 to 200 mg daily to achieve full control. Once rash is controlled, dose may be gradually tapered to a minimum maintenance dosage with eventual discontinuation based on clinical response (Ref).
Immune thrombocytopenia (alternative agent) (off-label use): Oral: 50 to 100 mg daily or 1 to 2 mg/kg/day; duration of therapy is ≥21 days (Ref).
Leprosy: Oral: 100 mg once daily as part of an appropriate combination regimen for 12 months for tuberculoid (paucibacillary) disease and 24 months for lepromatous (multibacillary) disease (Ref). Note: For resource-limited settings, the World Health Organization recommends 6 months for tuberculoid and 12 months for lepromatous (Ref).
Pemphigus vulgaris (adjunctive agent) (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) (Ref). Usual dose range: 50 to 200 mg daily (Ref). 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 (Ref).
Pneumocystis pneumonia (alternative agent) (off-label use):
Prophylaxis (primary or secondary): Oral: 100 mg once daily or in 2 divided doses as monotherapy (Ref) or 50 mg once daily in combination with weekly pyrimethamine and leucovorin or 200 mg once weekly in combination with weekly pyrimethamine and leucovorin. In patients with HIV, continue until CD4 count ≥200 cells/mm3 for ≥3 months in response to antiretroviral therapy (ART); may consider discontinuation of prophylaxis in patients with CD4 counts between 100 and 200 cells/mm3 who are receiving ART and have had an undetectable viral load for ≥3 to 6 months (Ref). In solid organ transplant recipients, the duration is typically at least 6 to 12 months depending on organ transplanted, immunosuppression, and institutional protocol (Ref).
Treatment (mild to moderate disease): Oral: 100 mg once daily in combination with trimethoprim for 21 days (Ref).
Pyoderma gangrenosum (alternative agent) (off-label use): Oral: 50 to 200 mg daily (Ref).
Relapsing polychondritis (off-label use): Oral: 25 to 200 mg daily (Ref).
Toxoplasma gondii encephalitis, primary prophylaxis (alternative agent) (off-label use):
Patients with HIV: Oral: 50 mg once daily, in combination with weekly pyrimethamine and leucovorin or 200 mg once weekly in combination with weekly pyrimethamine and leucovorin. Continue until CD4 count >200 cells/mm3 for >3 months in response to ART and viral load is undetectable; some experts discontinue prophylaxis in patients with CD4 counts between 100 and 200 cells/mm3 who are receiving ART and have had an undetectable viral load for ≥3 to 6 months (Ref).
Solid organ transplant recipients: Oral: 50 mg once daily, in combination with weekly pyrimethamine and leucovorin. Primary prophylaxis is often lifelong for donor-seropositive/recipient-seronegative (D+/R-) cardiac recipients, although discontinuation of prophylaxis may be considered with close clinical and laboratory monitoring; prophylaxis may be considered for D+/R- noncardiac recipients with duration dependent on patient-specific factors and/or institutional protocols (Ref).
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
The renal dosing recommendations are based upon the best available evidence and clinical expertise. Senior Editorial Team: Bruce Mueller, PharmD, FCCP, FASN, FNKF; Jason A. Roberts, PhD, BPharm (Hons), B App Sc, FSHP, FISAC; Michael Heung, MD, MS.
Altered kidney function:
eGFR ≥30 mL/minute/1.73 m2: No dosage adjustment necessary (Ref).
eGFR <30 mL/minute/1.73 m2: No dosage adjustment likely necessary based on pharmacokinetic properties (only 5% to 15% excreted in urine unchanged). However, use with caution and at the lower end of the indication-specific recommended dosing range when possible, with close monitoring of blood counts, as there are reports of dose-dependent hematologic toxicities (eg, methemoglobinemia, hemolysis) in patients with kidney impairment (Ref).
Hemodialysis, intermittent (thrice weekly): Unlikely to be significantly dialyzed (moderate Vd, moderate to high protein binding): Dose as for eGFR <30 mL/minute/1.73 m2 (Ref).
Peritoneal dialysis: Unlikely to be significantly dialyzed (moderate Vd, moderate to high protein binding): Dose as for eGFR <30 mL/minute/1.73 m2 (Ref).
CRRT: No dosage adjustment necessary (Ref).
PIRRT (eg, sustained, low-efficiency diafiltration): No dosage adjustment necessary (Ref).
There are no dosage adjustments provided in the manufacturer’s labeling; use with caution (Ref).
Refer to adult dosing.
(For additional information see "Dapsone (systemic): Pediatric drug information")
Dermatitis herpetiformis: Infants, Children, and Adolescents: Oral: Initial: 0.5 to 2 mg/kg/day in 1 to 2 divided doses; maximum initial daily dose: 50 mg/day (Ref). Increase dose as needed to achieve control; usual dose in adults: 100 to 200 mg/day (Ref). Once lesions controlled, may be tapered off or decreased to lowest effective dose (Ref).
Immune thrombocytopenia (alternative agent): Limited data available: Children and Adolescents: Oral: 1 to 2 mg/kg/day as a single daily dose; maximum dose: 100 mg/dose (Ref).
Leprosy: Note: In the United States, it is strongly recommended to contact the National Hansen's Disease Program for management of leprosy in pediatric patients (Ref).
National Hansen Disease Program Dosing: Children and Adolescents: Oral: 1 mg/kg/dose once daily as part of an appropriate combination regimen; maximum dose: 100 mg/dose (Ref). Treatment duration is 12 months for tuberculoid (paucibacillary) disease and 24 months for lepromatous (multibacillary) disease (Ref).
World Health Organization Dosing: Note: The World Health Organization recommends 6 months of treatment for tuberculoid disease and 12 months for lepromatous disease (Ref).
Children <10 years: Oral: 2 mg/kg/dose once daily as part of an appropriate combination regimen; maximum dose: 100 mg/dose.
Children ≥10 years and Adolescents <15 years:
<40 kg: Oral: 2 mg/kg/dose once daily as part of an appropriate combination regimen; maximum dose: 100 mg/dose.
≥40 kg: Oral: 50 mg once daily as part of an appropriate combination regimen.
Adolescents ≥15 years: Oral: 100 mg once daily as part of an appropriate combination regimen.
Linear IgA bullous dermatosis (LABD): Limited data available: Infants, Children, and Adolescents: Oral: Initial: 0.5 mg/kg/day in 1 to 2 divided doses with or without systemic corticosteroids; gradually increase dose (eg, at weekly intervals) until symptoms controlled to a usual maximum dose of 2 mg/kg/day (Ref); maximum reported daily dose: 4 mg/kg/day (Ref); usual adult dose: 25 to 150 mg/day (Ref).
Pneumocystis jirovecii pneumonia (alternative agent):
Prophylaxis (primary or secondary):
Persons with HIV (including infants with indeterminate HIV infection status):
Infants and Children: Note: In HIV-infected or indeterminate infants, continue until 12 months of age regardless of CD4 cell count/percentage. In children, continue until patient has been receiving antiretroviral therapy (ART) for ≥6 months and achieves a CD4 percentage ≥15% or age-specific CD4 cell count targets (age <6 years: ≥500 cells/mm3; age ≥6 years: ≥200 cells/mm3) for >3 consecutive months (Ref).
Daily regimen: Oral: 2 mg/kg/dose once daily (maximum daily dose: 100 mg/day).
Weekly regimen: Oral: 4 mg/kg/dose once weekly (maximum weekly dose: 200 mg/week) (Ref).
Adolescents: Note: Continue until CD4 cell count is ≥200 cells/mm3 for ≥3 months in response to ART; may also consider discontinuing when CD4 cell count is ≥100 cells/mm3 and viral load is undetectable for ≥3 to 6 months in response to ART (Ref).
Daily regimen:
Monotherapy: Oral: 100 mg once daily or 50 mg twice daily. Note: Not recommended in patients who are seropositive for Toxoplasma gondii (Ref).
Combination therapy: Oral: 50 mg once daily in combination with weekly pyrimethamine and leucovorin (Ref).
Weekly regimen: Oral: 200 mg once weekly in combination with weekly pyrimethamine and leucovorin (Ref).
Immunocompromised persons, not HIV-infected:
Infants, Children, and Adolescents:
Daily regimen: Oral: 2 mg/kg/dose once daily; maximum dose: 100 mg/dose. Adolescents may also receive 50 mg twice daily (Ref).
Weekly regimen: Oral: 4 mg/kg/dose once weekly; maximum dose: 200 mg/week (Ref).
Treatment, mild to moderate disease: Limited data available: Persons with HIV: Infants, Children, and Adolescents: Oral: 2 mg/kg/dose once daily in combination with trimethoprim for 21 days; maximum dose: 100 mg/dose (Ref).
Toxoplasma gondii encephalitis, primary prophylaxis (alternative agent): Persons with HIV: Note: Multiple regimens (daily or weekly dosing) and dosing units (mg/kg, mg/m2) presented; use caution.
Infants and Children: Note: In HIV-infected or indeterminate infants, continue until 12 months of age regardless of CD4 cell count. In children, continue until patient has been receiving antiretroviral therapy (ART) for ≥6 months and achieves age-specific target CD4 count (age 1 to <6 years: ≥15%; age ≥6 years: >200 cells/mm3) for >3 consecutive months (Ref).
Weight-directed dosing: Oral: 2 mg/kg/dose once daily in combination with pyrimethamine and leucovorin; maximum dose: 25 mg/dose (Ref).
BSA-directed dosing: Oral: 15 mg/m2/dose once daily in combination with pyrimethamine and leucovorin; maximum dose: 25 mg/dose (Ref).
Adolescents: Note: Continue primary prophylaxis following initiation of ART until CD4 count >200 cells/mm3 for >3 months; can consider discontinuation in patients with a CD4 count between 100 to 200 cells/mm3 who are receiving ART and have had an undetectable viral load for ≥3 to 6 months (Ref).
Daily regimen: Oral: 50 mg once daily in combination with pyrimethamine and leucovorin (Ref).
Weekly regimen: Oral: 200 mg once weekly in combination with pyrimethamine and leucovorin (Ref).
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
There are no dosage adjustments provided in the manufacturer's labeling; adult information suggests that no dosing adjustment is necessary for mild to moderate impairment; caution should be used in severe impairment due to risk of dose-dependent adverse reaction (Ref).
There are no dosage adjustments provided in the manufacturer's labeling; use with caution and monitor closely (Ref).
Dapsone is associated with methemoglobinemia, hemolytic anemia, neutropenia, and agranulocytosis. There are rare reports of aplastic anemia (Ref) and pancytopenia (Ref).
Methemoglobinemia: Symptoms may be absent or mild and nonspecific (eg, malaise (Ref), headache, fatigue, tachycardia, (Ref) but can be severe with dyspnea, cyanosis, and hypoxia (Ref), and it has been fatal (Ref). Mean peak methemoglobin of 7.6% (range: 2.1% to 34.1%) of hemoglobin has been described (Ref). A "saturation gap" between SpO2A and SaO2, chocolate-brown arterial blood, and cyanosis presenting as pasty brown mucous membranes are considered characteristic (Ref). Dapsone discontinuation with supplemental oxygen as indicated generally leads to resolution within 2 weeks (Ref); however, cases have taken longer to resolve (Ref). Reported incidences vary depending on case definitions: Cyanosis or hypoxia (O2 saturation ≤95%) with methemoglobin level ≥3% occurred in 20% of those taking dapsone in one study (Ref). Methemoglobin levels >1.5% occurred 46% in another study (Ref).
Hemolytic anemia: Dapsone-induced hemolytic anemia may be found on routine monitoring or after presentation with mild symptoms (eg, fatigue, exertional dyspnea) in those without G6PD deficiency (Ref). Patients with G6PD deficiency present with more severe symptoms (eg, tachycardia, tachypnea, mild hypoxia in room air) (Ref). Decreased hemoglobin has been reported in patients without G6PD deficiency (Ref); however, patients with G6PD deficiency experience more significant reductions (Ref)). Hemolytic anemia has been fatal in resource limited settings despite transfusion (Ref). Recovery usually occurs 8 to 10 days after discontinuation but has taken up to ~3 months (Ref). Up to 10% may require packed red cells (Ref).
Neutropenia: Neutropenia (Ref) can be severe (Ref) and has been fatal (Ref). ANC generally recovers ≤1 month after discontinuation (Ref).
Agranulocytosis: Approximately 90% of cases present with fever and other symptoms of infection while the remainder are detected on routine CBC monitoring (Ref). Absolute neutrophil counts as low as 0 cells/mm3 have been reported (Ref) and has been fatal (Ref). Neutrophils normalize a median of 10 days after discontinuation (Ref).
Mechanism:
Methemoglobinemia: Dose-related; hydroxylamine metabolite oxidizes ferrous iron (Fe2+) in heme to ferric iron (Fe3+), converting hemoglobin to methemoglobin which has reduced oxygen carrying capacity. NADH dependent cytochrome b5 reductase, NADPH-dependent methemoglobin reductase, ascorbic acid, and glutathione mediated removal of methemoglobin are overwhelmed and the proportion of methemoglobin to hemoglobin is increased (Ref).
Hemolytic anemia: Dose-related; hydroxylamine metabolite and nitroso-dapsone, formed during conversion of hemoglobin to methemoglobin, generate reactive oxygen radicals. In G6PD deficiency, these accumulate and directly damage red blood cell membranes leading to hemolysis. The hydroxylamine metabolite can directly affect phosphorylation of membrane proteins, leading to hemolysis in those without G6PD deficiency (Ref).
Neutropenia and Agranulocytosis: Non–dose-related; hydroxylamine is toxic to bone marrow myeloid cells (Ref)
Onset:
Methemoglobinemia: Varied; ranges from 1 day (Ref) to 5 months (Ref) or longer (Ref).
Hemolytic anemia: Varied; presenting within 24 to 72 hours then worsening until days 7 to 8 in individuals with G6PD deficiency (Ref). May present later in individuals without G6PD deficiency with reports ranging from 11 to 71 days (Ref).
Neutropenia: Varied; typical time to onset ≤7 days (Ref).
Agranulocytosis: Varied; median duration of dapsone treatment before symptom development was 56 days (range: 6 to 133 days) (Ref).
Risk factors:
Methemoglobinemia:
• More common with higher doses (eg, overdose) (Ref), but has been reported with treatment and prophylactic doses (Ref)
• Kidney impairment (Ref)
• Mixed evidence for low cytochrome b5 reductase (Cb5R) levels or heterozygosity for Cb5R deficiency (Ref)
• G6PD deficiency (Ref)
• Concurrent methemoglobinemia-inducing agents (Ref)
• For symptoms:
- Anemia (Ref)
- Blood loss (Ref)
- Coronary artery disease (Ref)
- Lung disease or pneumonia (Ref)
- Sepsis (Ref)
- Abnormal hemoglobin species (eg, carboxyhemoglobin, sulfhemoglobin, or sickle hemoglobin) (Ref)
Hemolytic anemia:
• Dose (Ref)
• G6PD deficiency (Ref)
• Low ideal body weight (Ref)
• Kidney impairment (Ref)
• Compromised bone marrow (eg, hematopoietic stem cell transplantation) (Ref)
• Hemoglobin H disease (Ref)
Neutropenia:
• Older age (Ref)
• Underlying disease (Ref)
• Females (Ref)
• Concurrent medications (Ref)
Agranulocytosis:
• Older age (>60 years) (Ref)
• Non-Caucasian descent (Ref)
• Preexisting severe inflammatory conditions (eg, dermatitis herpetiformis) (Ref)
• N-acetyltransferase deficiency (Ref)
Hepatic injury ranges from mild increased serum transaminases to fulminant hepatic failure (Ref). Hyperbilirubinemia may occur more frequently in G6PD deficient patients (Ref). Hepatotoxicity is most often associated with signs of hypersensitivity, as part of drug rash with eosinophilia and systemic symptoms (DRESS) (Ref). Liver injury is typically cholestatic or mixed (Ref). Most cases resolve within 2 to 8 weeks of discontinuing dapsone; although, severe cholestatic injury may be prolonged (Ref).
Mechanism: Unknown: Non–dose-related; possibly hypersensitivity mechanism, through metabolism to a reactive, toxic metabolite (Ref).
Onset: Varied; duration of therapy prior to onset of hepatotoxicity is typically within a few days to weeks; although, can be delayed up to 5 months (Ref). A shorter onset occurs upon rechallenge (Ref).
Risk factors:
• HLA-B*13:01 has been associated with hepatotoxicity (Ref)
Drug rash with eosinophilia and systemic symptoms (DRESS; previously known as dapsone or sulfone syndrome) (Ref) has been reported. In most cases, predominant hepatotoxicity (Ref) is noted, although pancreatitis (Ref), acute kidney injury (Ref), or eosinophilic pneumonitis (Ref) may also occur. Fever, along with other cutaneous reactions may be reported, including fixed drug eruption, photosensitivity, maculopapular rash, and erythematous plaques (Ref). Additional serious cutaneous adverse reactions (SCARs) include Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) (Ref) and acute generalized exanthematous pustulosis (AGEP) (Ref). Following discontinuation of dapsone, resolution occurs within days to several months (mean: 27 days); although, may result in fatality in 10% of cases (Ref). In some patients, hypothyroidism and/or diabetes mellitus may develop months after discontinuation (Ref).
Mechanism: Delayed hypersensitivity reactions: Non–dose-related, immunologic. Delayed hypersensitivity reactions are T-cell mediated (Ref).
Onset: Delayed hypersensitivity reactions: Varied. Serious cutaneous adverse reactions, usually occur 1 to 8 weeks after initiation (Ref). A mean of a ~32 days has been reported with dapsone but may also occur up to 6 months after initiation (Ref).
Risk factors:
• HLA-B*13:01 has been associated with SCARs (Ref).
• Cross-reactivity may occur in patients with a history of a hypersensitivity reaction to sulfonamide antibiotics (eg, sulfamethoxazole/trimethoprim) (Ref), although dapsone may be considered as an option in patients with mild reactions to sulfonamide antibiotics (Ref).
• Younger patients may be at an increased risk for development of DRESS; older patients have decreased production of toxic metabolites due to decreased enzyme activity associated with aging (Ref).
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.
Frequency not defined:
Cardiovascular: Tachycardia
Endocrine & metabolic: Albuminuria, hypoalbuminemia (without proteinuria)
Gastrointestinal: Abdominal pain, nausea, vomiting
Genitourinary: Male infertility
Hematologic & oncologic: Reticulocytosis
Infection: Infectious mononucleosis (infectious mononucleosis-like syndrome)
Nervous system: Headache, insomnia, psychomotor impairment, psychosis, vertigo
Neuromuscular & skeletal: Lupus-like syndrome
Ophthalmic: Blurred vision
Otic: Tinnitus
Renal: Nephrotic syndrome, renal papillary necrosis
Postmarketing:
Dermatologic: Acute generalized exanthematous pustulosis (Vas 2013), fixed drug eruption (Sauvetre 2015), maculopapular rash (Kosseifi 2006), phototoxicity (Kar 2008), Stevens-Johnson syndrome (Tempark 2017), toxic epidermal necrolysis (Tempark 2017)
Gastrointestinal: Pancreatitis (Das 2014)
Hematologic & oncologic: Agranulocytosis (St Clair 2021), aplastic anemia (Meyerson 1994), decreased hemoglobin (Khatri 2020, Murphy 2016), hemolysis (Khatri 2020, Murphy 2016), hemolytic anemia (Khatri 2020, Murphy 2016), methemoglobinemia (Shenouda 2022), neutropenia (Hsieh 2020), pancytopenia (Abdur Raheem 2022)
Hepatic: Cholestatic jaundice, hepatic failure (Devarbhavi 2018), hepatitis (Devarbhavi 2018), hyperbilirubinemia (Pamba 2012), increased serum transaminases (Abidi 2006)
Hypersensitivity: Drug reaction with eosinophilia and systemic symptoms (Kang 2021)
Nervous system: Peripheral neuropathy (Waldinger 1984)
Renal: Acute kidney injury (Pai 2017)
Respiratory: Eosinophilic pneumonitis (Kinehara 2015)
Miscellaneous: Fever (Kosseifi 2006)
Hypersensitivity to dapsone or any component of the formulation.
Canadian labeling: Additional contraindications (not in US labeling): Advanced amyloidosis of the kidneys.
Concerns related to adverse effects:
• 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.
• Diabetes mellitus: Dapsone may artificially lower HbA1c by reducing erythrocyte survival time through hemolysis (Lai 2012).
• Leprosy: New or severe dermatological reactions require discontinuation of therapy; however, leprosy reactional states (eg, erythema nodosum leprosum) do not require discontinuation.
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; dose-related hemolysis may occur.
• Methemoglobin reductase deficiency: Use with caution in patients with methemoglobin reductase deficiency; dose-related hemolysis may occur.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Tablet, Oral:
Generic: 25 mg, 100 mg
Yes
Tablets (Dapsone Oral)
25 mg (per each): $2.47 - $6.00
100 mg (per each): $3.02 - $9.00
Disclaimer: A representative AWP (Average Wholesale Price) price or price range is provided as reference price only. A range is provided when more than one manufacturer's AWP price is available and uses the low and high price reported by the manufacturers to determine the range. The pricing data should be used for benchmarking purposes only, and as such should not be used alone to set or adjudicate any prices for reimbursement or purchasing functions or considered to be an exact price for a single product and/or manufacturer. Medi-Span expressly disclaims all warranties of any kind or nature, whether express or implied, and assumes no liability with respect to accuracy of price or price range data published in its solutions. In no event shall Medi-Span be liable for special, indirect, incidental, or consequential damages arising from use of price or price range data. Pricing data is updated monthly.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Tablet, Oral:
Generic: 100 mg
Oral: Administer with meals if GI upset occurs.
Oral: May administer with meals if GI upset occurs (Ref).
Dermatitis herpetiformis: Treatment of dermatitis herpetiformis.
Leprosy: Treatment of leprosy (due to susceptible strains of Mycobacterium leprae).
Aphthous ulcers (severe); Bullous pemphigoid; Bullous systemic lupus erythematosus; Immune thrombocytopenia; Pemphigus vulgaris; Pneumocystis pneumonia, prophylaxis or treatment; Pyoderma gangrenosum; Relapsing polychondritis; Toxoplasma gondii encephalitis, prophylaxis
Dapsone may be confused with Diprosone
Substrate of CYP2C19 (Minor), CYP2C8 (Minor), CYP2C9 (Minor), CYP2E1 (Minor), CYP3A4 (Major with inducers), CYP3A4 (Minor with inhibitors); Note: Assignment of Major/Minor substrate status based on clinically relevant drug interaction potential;
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program by clicking on the “Launch drug interactions program” link above.
Antimalarial Agents: May increase adverse/toxic effects of Dapsone (Systemic). Specifically, concomitant use of antimalarial agents with dapsone may increase the risk of hemolytic reactions. Dapsone (Systemic) may increase adverse/toxic effects 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. Risk D: Consider Therapy Modification
Atazanavir: Dapsone (Systemic) may increase adverse/toxic effects of Atazanavir. Specifically, the risk of hyperbilirubinemia may be increased. Risk C: Monitor
Bacillus clausii: Antibiotics may decrease therapeutic effects of Bacillus clausii. Management: Bacillus clausii should be taken in between antibiotic doses during concomitant therapy. Risk D: Consider Therapy Modification
BCG (Intravesical): Antibiotics may decrease therapeutic effects of BCG (Intravesical). Risk X: Avoid
BCG Vaccine (Immunization): Antibiotics may decrease therapeutic effects of BCG Vaccine (Immunization). Risk C: Monitor
Cholera Vaccine: Antibiotics may decrease therapeutic effects of Cholera Vaccine. Management: Avoid cholera vaccine in patients receiving systemic antibiotics, and within 14 days following the use of oral or parenteral antibiotics. Risk X: Avoid
CYP3A4 Inducers (Moderate): May decrease serum concentration of Dapsone (Systemic). Risk C: Monitor
CYP3A4 Inducers (Strong): Dapsone (Systemic) may increase adverse/toxic effects of CYP3A4 Inducers (Strong). CYP3A4 Inducers (Strong) may decrease serum concentration of Dapsone (Systemic). Management: Consider alternatives to this combination when possible. Monitor for decreased dapsone efficacy if combined with strong CYP3A4 inducers. Risk D: Consider Therapy Modification
Dapsone (Topical): May increase adverse/toxic effects of Methemoglobinemia Associated Agents. Risk C: Monitor
Fecal Microbiota (Live) (Oral): May decrease therapeutic effects of Antibiotics. Risk X: Avoid
Fecal Microbiota (Live) (Rectal): Antibiotics may decrease therapeutic effects of Fecal Microbiota (Live) (Rectal). Risk X: Avoid
Immune Checkpoint Inhibitors (Anti-PD-1, -PD-L1, and -CTLA4 Therapies): Antibiotics may decrease therapeutic effects of Immune Checkpoint Inhibitors (Anti-PD-1, -PD-L1, and -CTLA4 Therapies). Risk C: Monitor
Lactobacillus and Estriol: Antibiotics may decrease therapeutic effects of Lactobacillus and Estriol. Risk C: Monitor
Local Anesthetics: Methemoglobinemia Associated Agents may increase adverse/toxic effects of Local Anesthetics. Specifically, the risk for methemoglobinemia may be increased. Risk C: Monitor
Methotrexate: Dapsone (Systemic) may increase serum concentration of Methotrexate. Management: Avoid coadministration of dapsone and methotrexate if possible. If coadministration is required, monitor closely for methotrexate toxicities (eg, hematological, gastrointestinal, nephrotoxicity toxicities). Risk D: Consider Therapy Modification
Mycophenolate: Antibiotics may decrease active metabolite exposure of Mycophenolate. Specifically, concentrations of mycophenolic acid (MPA) may be reduced. Risk C: Monitor
Nitric Oxide: May increase adverse/toxic effects of Methemoglobinemia Associated Agents. Combinations of these agents may increase the likelihood of significant methemoglobinemia. Risk C: Monitor
Prilocaine: Methemoglobinemia Associated Agents may increase adverse/toxic effects of Prilocaine. Combinations of these agents may increase the likelihood of significant methemoglobinemia. Management: Monitor for signs of methemoglobinemia when prilocaine is used in combination with other agents associated with development of methemoglobinemia. Avoid use of these agents with prilocaine/lidocaine cream in infants less than 12 months of age. Risk C: Monitor
Sodium Nitrite: Methemoglobinemia Associated Agents may increase adverse/toxic effects of Sodium Nitrite. Combinations of these agents may increase the likelihood of significant methemoglobinemia. Risk C: Monitor
Sodium Picosulfate: Antibiotics may decrease therapeutic effects 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. Risk D: Consider Therapy Modification
Trimethoprim: May increase serum concentration of Dapsone (Systemic). Dapsone (Systemic) may increase serum concentration of Trimethoprim. Risk C: Monitor
Typhoid Vaccine: Antibiotics may decrease therapeutic effects of Typhoid Vaccine. Only the live attenuated Ty21a strain is affected. Management: Avoid use of live attenuated typhoid vaccine (Ty21a) in patients being treated with systemic antibacterial agents. Postpone vaccination until 3 days after cessation of antibiotics and avoid starting antibiotics within 3 days of last vaccine dose. Risk D: Consider Therapy Modification
In uncontrolled studies and published surveys, dapsone did not affect female reproduction. Male infertility is noted as an adverse event in the dapsone product labeling.
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. Avoid use during the first trimester when alternative therapies are available. Do not use dapsone unless the pregnant person and biologic father have normal G6PD activity (HHS [OI adult 2024]).
Dapsone may be used in pregnant patients requiring maintenance therapy of either leprosy or dermatitis herpetiformis. Dapsone may also be used in pregnant patients for prophylaxis of Toxoplasma gondii encephalitis (alternative therapy), or prophylaxis and treatment of Pneumocystis pneumonia (alternative therapy) (HHS [OI adult 2024]).
Dapsone is present in breast milk.
Dapsone can be detected in the serum of nursing infants. Hemolytic anemia has been reported in a breastfed infant (Sanders 1982). Due to the potential for serious adverse reactions in the nursing infant, the manufacturer recommends a decision be made whether to discontinue nursing or to discontinue the drug, considering the importance of treatment to the mother. Other sources consider dapsone, when used in usual doses, to be compatible with breastfeeding. Breastfed infants should be monitored for hemolysis and jaundice especially premature infants or infants <1 month of age. Avoid breastfeeding infants with G-6-PD deficiency (WHO 2002).
Check G6PD levels (prior to initiation); CBC (weekly for first month, monthly for 6 months and semiannually thereafter); liver function tests (baseline and periodic). Monitor patients for signs of jaundice, hemolysis, and blood dyscrasias.
May artificially lower HbA1c by reducing erythrocyte survival time through hemolysis. If the patient has diabetes, consider alternative methods to monitor diabetes control other than HbA1c (Lai 2012).
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.
Protein binding: Dapsone: 70% to 90%; Metabolite: ~99% (Zuidema 1986).
Distribution: Vd: 1.5 L/kg (Zuidema 1986).
Metabolism: Hepatic (acetylation and hydroxylation); forms multiple metabolites (Zuidema 1986).
Half-life elimination: Children: 15.1 hours (Mirochnick 1993); Adults: 28 hours (range: 10 to 50 hours).
Time to peak: 4 to 8 hours.
Excretion: Urine (~85%, mainly as metabolites [5 to 15% unchanged (Zuidema 1986)]).