Dapsone
DAPSONE
- Leprostatic drug.
- Acedapsone – Repository form of dapsone.
- Single IM injection maintains inhibitory levels of dapsone in tissues for up to 3 months.
MECHANISM OF ACTIONS:
PHARMACOKINETICS:
- Dose of Dapsone
- 1-2 mg/kg
- Absorption: Completely absorbed after oral administration.
Distribution:
- Approximately 70% bound to plasma protein.
- main metabolite, monoacetyl dapsone, is nearly 100% protein bound.
Metabolism:
- Acetylated in liver.
- Variable plasma t1/2, mostly
- Elimination takes 1-2 weeks or longer
- Metabolites excreted in bile & urine
USES:
- Dermatitis Herpetiformis – Drug of choice.
- Mycobacterium leprae infections (leprosy)/hansen’s disease.
- WHO regime for paucibacillary leprosy is 100 mg Dapsone daily + Rifampicin monthly (600 mg)
- Acne.
- Pneumocystis pneumonia.
- Alternative drug for Pneumocystis treatment jirooeci infection in AIDS patients.
- Generalised lichen planus
- Toxoplasmosis – Prophylaxis
ADVERSE ACTION:
- Haemolytic anaemia – Most common.
- Gastric intolerance-nausea & anorexia, headache, paresthesias, mental symptoms & drug fever.
- Allergic rashes, fixed drug eruption, hypermelanosis, phototoxicity & rarely exfoliative dermatitis.
- Hepatitis & agranulocytosis.
- DDS syndrome/Dapsone reaction/Sulfone syndrome.
- Causes gastrointestinal irritation fever, skin rash, methemoglobinemia & hemolysis particularly in G-6-PD defrcint patients
DRUG INTERACTIONS:
- Folic acid antagonists (such as pyrimethamine), nitrofurantoin, primaquine.
- This medication may decrease the effectiveness of combination-type birth control pills.
Exam Question
- Dapsone is used in treatment & therapeutic diagnosis of dermatitis herpetiformis.
- Both Dapsone & Systemic steroids drugs are used in generalised lichen planus.
- Rifampicin, dapsone and clofazimine are used if HIV infected patient develops multibacillary leprosy.
- Hemolytic anaemia is the commonest side effect of Dapsone.
- Dose of Dapsone is 1-2 mg/kg.
- WHO regime for paucibacillary leprosy is 100 mg Dapsone daily + Rifampicin monthly (600 mg).
- Fixed drug eruption (FDE) is an adverse cutaneous reaction to an ingested dapsone.
Don’t Forget to Solve all the previous Year Question asked on Dapsone
