Sulfone antibiotic / immunomodulator
Dapsone
Brand names: various
Adult dose
Dose: Leprosy: 100mg OD (per WHO MDT); PCP prophylaxis: 100mg OD; Dermatitis herpetiformis: 50mg OD, titrate
Route: Oral
Frequency: OD
Clinical pearls
- WHO leprosy multidrug therapy / UKHSA
- BHIVA: 2nd-line PCP prophylaxis when co-trimoxazole intolerant
- BAD: dermatitis herpetiformis (with strict gluten-free diet)
- Always check G6PD before initiation
Contraindications
- G6PD deficiency (severe haemolysis — test before initiation)
- Severe anaemia
- Porphyria
- Hypersensitivity to sulfonamides
Side effects
- Methaemoglobinaemia (cyanosis, headache, dyspnoea)
- Haemolytic anaemia (especially G6PD)
- Agranulocytosis
- Dapsone hypersensitivity syndrome (DRESS-like, often weeks 2–6)
- Hepatotoxicity
- Peripheral neuropathy
Interactions
- Trimethoprim (additive haemolysis)
- Rifampicin (reduced dapsone levels)
- Probenecid
Monitoring
- FBC (weekly first month, monthly ×6)
- LFTs
- Methaemoglobin
- Reticulocytes
- Skin / hypersensitivity
Reference: BNF; WHO leprosy; BHIVA OI; BAD; UKHSA; https://bnf.nice.org.uk/drugs/dapsone/. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Calculators
- Centor / McIsaac Score for Strep Pharyngitis · Throat
- FeverPAIN Score for Strep Throat · Throat
- Jarisch-Herxheimer Reaction Severity Assessment · Treatment Reactions
- PID Severity (CDC Diagnostic Criteria) · Gynaecological Infections
- Gustilo-Anderson Classification (Open Fractures) · Fracture Classification
- DRIP Score for Drug-Resistant Pneumonia · Pneumonia
Pathways
- Infective Endocarditis · ESC 2023 Infective Endocarditis Guidelines; NICE NG41
- Eczema Herpeticum · BAD; NICE CKS
- Suspected Bacterial Meningitis (Adult) · NICE NG240 (2024); NICE NG143 (paeds)
- Clostridioides difficile Colitis · NICE NG199 (2021); IDSA/SHEA 2021
- Returning Traveller — Fever · NaTHNaC; PHE; ESCMID 2018
- Malaria — Diagnosis & Management · PHE 2016; WHO 2023