This document summarizes information about the treatment of leprosy. It discusses that leprosy is caused by Mycobacterium leprae and can be successfully treated with multidrug therapy combinations, though nerve damage cannot be reversed. Dapsone is one of the first-line drugs used along with rifampicin and clofazimine according to the WHO recommended multidrug therapy regimen, which involves taking these drugs for either 6 months for paucibacilliary leprosy or 12 months for multibacilliary leprosy. The document also outlines dosing guidelines for both adults and children.

1. Presented by:
Dr Rajesh Kumar Shah
Resident (MD-Pharmacology)
KUSMS, Dhulikhel, Nepal.

2.  Leprosy is a chronic granulomatous
infection of peripheral nerves and skin.
 Caused by Mycobacterium leprae
(hence contagious)
 May be Paucibacilliary or Multibacillary.

3.  It can be successfully treated with low
relapse rates, with suitable combination of
drugs.
 However, the nerve damage that has already
occurred due to the disease (in limbs and
eyes) cannot currently be satisfactorily be
reversed or treated.
 Hence, pharmacotherapy should be initiated
as soon as possible.

4. Classification/List of Antileprotic
Drugs
A) First-line drugs:
1) Sulfones: DAPSONE
2) Antitubercular drugs : RIFAMPICIN
(rifampin) , ETHIONAMIDE
3) Phenazine derivative: CLOFAZIMINE

5. B) Alternative/ Second-line drugs:
1) Fluoroquinolones:
like OFLOXACIN,
MOXIFLOXACIN,
PEFLOXACIN,
SPARFLOXACIN
2) MINOCYCLINE
3) Macrolide: like CLARITHROMYCIN

6. DAPSONE
 It is chemically 4,4-DiAmino diPhenyl
SulphONE (DDS).
 bacteriostatic; weak bactericidal.
 Concentrates in skin (especially
lepromatous skin), muscle, liver and
kidney.

7. Mechanism of Action:
Closely related to Sulphonamide group of
drugs and have a similar m.o.a.
Chemical structure similar to PABA.
Bacteria like M. leprae, takes PABA from
external environment and utilize it for
synthesis of folic acid. Dapsone when taken
inside the bacterial cell, competes with PABA
as substrate for folate synthase enzyme and
prevents synthesis of normal folic acid by the
bacteria. Folic acid is essential for the growth
and metabolism of bacteria. In its absence,
bacterial growth is inhibited.

8. Uses/Indications:
1) In the treatment of leprosy: as one of the
first-line drugs in a MDT (Multi-Drug Therapy)
regimen against leprosy.
2) In Chloroquine-resistant cases of
Plasmodium falciparum malaria
3) In prevention and treatment of
Pneumocystis jirovecii pneumonia in AIDS
patients.
4) IN Toxoplasma gondii infections.
5) In acne (topical form used)

9. Adverse Drug Effects (ADE):
1) Haemolysis : mild; dose-dependent
2) Sulfone syndrome: after 4 to 6 weeks of
DDS therapy. Characterized by desquamation
of skin, lymphadenopathy, jaundice, fever and
anaemia.
3) Rarely : Haemolytic anaemia,
Methaemoglobinaemia, Agranulocytosis,
Hepatitis,Mental symptoms
4) Gastric intolerance: nausea, anorexia;
decreases later.
5) Cutaneous reactions : pruritis, rashes

10. Contraindications:
1) Severe anaemia (< 7g/dl)
2) In patients with G-6-PD (Glucose 6
Phosphate Dehydrogenase) deficiency
3) In patient hypersensitive to
sulfonamides
4) In patients with Methaemoglobinaemia

11. Treatment for leprosy
a) Monotherapy with Dapsone was used
in past: Discontinued now due to
emergence of strains resistant to
Dapsone.
b) MDT (Multi-Drug Therapy) regimen as
recommended by WHO followed
nowadays:

12. WHO/GDG (2018) MDT
regimen includes:

13. WHO/GDG (2018)
recommended MDT regimen
includes:A) In adult patients:
i) Drugs: Rifampicin 600mg once a
month(under supervision) + Dapsone 100mg once
daily (self-administered) + Clofazimine 300mg once
a month (under supervision) + Clofazimine 50mg
once daily (self-administered)
ii) Total duration of drug therapy:
a) In patients with multibacillary leprosy
(MBL): 12 months (1 year)
b) In patients with paucibacillary leprosy
(PBL): 6 months

14. B) In Children (10 to 14 years of age):
i) Drugs: Rifampicin 450mg once a
month + Dapsone 50mg once daily +
Clofazimine 150mg once a month +
Clofazimine 50mg on alternate days.
ii) Total duration of drug therapy:
a) In patients with multibacillary
leprosy (MBL): 12 months (1 year)
b) In patients with paucibacillary
leprosy (PBL): 6 months

15. C) In children <10 years old or <40kg in weight:
i) Drugs: Rifampicin 10 mg/kg once a month +
Dapsone 2 mg/kg once daily + Clofazimine 100mg
once a month + Clofazimine 50mg twice weekly.
ii) Total duration of drug therapy:
a) In patients with multibacillary leprosy (MBL):
12 months (1 year)
b) In patients with paucibacillary leprosy (PBL): 6
months

16. For drug-resistant leprosy:

17. THANK YOU