Drugs Used In Leprosy - Dapsone

• Oldest,cheapest and most widely used
• Di-amino-Di-phenyl Sulfone
• Structurally similar to sulpha drugs

Mechanism of Action:

• Similar to sulphonamides
• Lepra bacilli utilise PABA to synthesize folic acid. Dapsone competes with PABA inhibiting folate synthesis.

Pharmacokinetics:

• Well absorbed orally
• Widely distributed into the skin,muscle, liver, kidneys etc.
• Metabolised by acetylation and conjugation in the liver. Undergoes enterohepatic cycling.

Adverse Effects:

• Dose related:
• Hemolytic anemia especially in G6PD Deficiency.
• Methhemoglobinemia
• GI Adverse effects
• Dermatitis, pruritis and peripheral neuropathy
• Headache, drug fever
• Hepatitis
• May cause 'Sulfone syndrome' or Lepra reaction - -> Erythema nodosum Leprosum (ENL)
• occurs due to antigen release from lepra bacilli