Dapsone: dosing, contraindications, cautions, adverse events, and monitoring
| Dose and drug safety considerations . | Details . |
|---|---|
| Typical dosing regimens | |
| Leprosy | 100 mg daily (in multiple drug regimens) |
| Malaria prophylaxis | 100 mg weekly (with 12.5 mg pyrimethamine) |
| Dermatitis herpetiformis | 50 mg daily titrated to 300 mg daily if required. In responding patients, reduced to the minimum effective dose (typically 25-100 mg). |
| Contraindications | Include hypersensitivity to sulphonamides or sulphones, severe anemia, porphyria, and severe glucose-6-phosphate-dehydrogenase (G6PD) deficiency |
| Cautions | Cardiac or pulmonary disease, anemia, and G6PD or methemoglobin reductase deficiency. |
| Adverse events | |
| Hemolysis | Occurs in most patients above 200 mg (or above 50 mg if G6PD deficiency). At 100-150 mg, hemoglobin falls by 2 0g/L in ∼10%. Treatment does not need to be interrupted for mild hemolysis. |
| Methemoglobinemia | Cyanosis may be visible at levels >3%. Tachycardia, headache, nausea, weakness, and abdominal pain may occur at higher levels. |
| Hypersensitivity reaction | May present with rash (can be severe, eg, erythema multiforme, exfoliative dermatitis), fever, lymphadenopathy, hepatic dysfunction, or leukocytosis. Prevalence 1.4%. Most cases are within 6 weeks of onset. 10% fatality. Stop drug, consider systemic steroids. |
| Peripheral neuropathy | Rare. Primarily motor. Complete resolution typical with dose reduction or withdrawal |
| Other effects | Agranulocytosis, rash, photosensitivity, pruritis, tachycardia, headache, hepatitis, insomnia, psychosis, anorexia, nausea, and vomiting |
| Laboratory monitoring | |
| Baseline | Complete blood count (CBC) with differential and reticulocyte counts |
| Liver and renal function | |
| G6PD level | |
| Follow-up | CBC with differential and reticulocyte counts every 2 weeks for 3 months and then every 3-4 months (increase frequency if dose is increased) |
| Liver and renal function every 3-4 months | |
| Methemoglobin as clinically indicated | |
| Dose and drug safety considerations . | Details . |
|---|---|
| Typical dosing regimens | |
| Leprosy | 100 mg daily (in multiple drug regimens) |
| Malaria prophylaxis | 100 mg weekly (with 12.5 mg pyrimethamine) |
| Dermatitis herpetiformis | 50 mg daily titrated to 300 mg daily if required. In responding patients, reduced to the minimum effective dose (typically 25-100 mg). |
| Contraindications | Include hypersensitivity to sulphonamides or sulphones, severe anemia, porphyria, and severe glucose-6-phosphate-dehydrogenase (G6PD) deficiency |
| Cautions | Cardiac or pulmonary disease, anemia, and G6PD or methemoglobin reductase deficiency. |
| Adverse events | |
| Hemolysis | Occurs in most patients above 200 mg (or above 50 mg if G6PD deficiency). At 100-150 mg, hemoglobin falls by 2 0g/L in ∼10%. Treatment does not need to be interrupted for mild hemolysis. |
| Methemoglobinemia | Cyanosis may be visible at levels >3%. Tachycardia, headache, nausea, weakness, and abdominal pain may occur at higher levels. |
| Hypersensitivity reaction | May present with rash (can be severe, eg, erythema multiforme, exfoliative dermatitis), fever, lymphadenopathy, hepatic dysfunction, or leukocytosis. Prevalence 1.4%. Most cases are within 6 weeks of onset. 10% fatality. Stop drug, consider systemic steroids. |
| Peripheral neuropathy | Rare. Primarily motor. Complete resolution typical with dose reduction or withdrawal |
| Other effects | Agranulocytosis, rash, photosensitivity, pruritis, tachycardia, headache, hepatitis, insomnia, psychosis, anorexia, nausea, and vomiting |
| Laboratory monitoring | |
| Baseline | Complete blood count (CBC) with differential and reticulocyte counts |
| Liver and renal function | |
| G6PD level | |
| Follow-up | CBC with differential and reticulocyte counts every 2 weeks for 3 months and then every 3-4 months (increase frequency if dose is increased) |
| Liver and renal function every 3-4 months | |
| Methemoglobin as clinically indicated | |