Antileprosy drugs have been described with their pharmacology also this topic covers Multidrug treatment for leprosy including paucibacillary and multibacillary leprosy and lepra reactions
2. Objectives
• Classify anti-leprosy drugs
• Discuss the Mechanism of action, relevant
pharmacokinetics, adverse effects and
contraindications of antileprosy drugs
• Describe the treatment of Paucibacillary and
multibacillary leprosy
• Describe the treatment of type 1 and 2 lepra
reaction
5. • Chemically related to sulfonamides & shares a
common mechanism of action
• Leprostatic at very low concentration
• Not used for other pyogenic infections
• Not used alone always used with rifampicin and/or
clofazimine in MDT for leprosy
Dapsone's chemical name is 4,4'-diamino diphenyl sulfone
6. • Slowly and completely absorbed from GIT
• 70% plasma protein bound
• Produces ten times more concentration
in diseased skin than in normal skin
• t ½ - 24 hrs
• 70-80% excreted in urine
• Drug is excreted in milk
PharmacokineticsDAPSONE
7. • Act as competitive inhibitor of the enzyme DIHYDROPTEROATE SYNTHETASE
(DHPS).
Mechanism of ActionDAPSONE
8. Mechanism of Action
• Folate is necessary for the cell to synthesize nucleic acids and
in its absence cells will be unable to divide.
• Hence the sulfonamide antibacterial exhibit a bacteriostatic
effect
• Folate is not synthesized in mammalian cells, but is instead a
dietary requirement. This explains the selective toxicity to
bacterial cells of these drugs.
DAPSONE
9. Resistance
❑ Secondary resistance usually is seen in lepromatous (multibacillary)
patients treated with a single drug.
RESISTANCE
PRIMARY
Untreated
Patients
SECONDARY
Patients on
treatment
❑ mutation in folP1 of M. leprae
DAPSONE
10. • Mild hemolytic anemia in G6PD deficiency
• Methemoglobinemia
Adverse effectDAPSONE
Dapsone to be avoided if Hb is < 7 gm/dl
13. • Leprosy
• With pyrimethamine
– Resistant Falciparum malaria
– P Jirovecii Infection
– Toxoplasmosis
IndicationsDAPSONE
14. • Phenazine dye
• Leprostatic
• Anti-inflammatory action:
– Major advantage used in ENL
• BIOLOGICAL LAG 6-7 weeks
• Clinical improvement visible by 6th month
CLOFAZIMINE
15. Mechanism of ActionCLOFAZIMINE
• Preferentialy binds to mycobacterial DNA
• Interferes with template function of the DNA
• Alteration of membrane structure and
transport function
17. Adverse EffectsCLOFAZIMINE
• Reddish black discoloration of nonexposed
skin
• Discoloration of hair and body secretions
• Dryness of skin, itching & scaling
• Abdominal pain
SMALL BOWEL
SYNDROME
Persistent diarrhea
Abdominal pain Weight loss
18. 1. Pregnancy
2. Liver and kidney disease
3. GI symptoms
ContraindicationsCLOFAZIMINE
19. • Most potent cidal drug for M Leprae
• Rifampicin kills 99.99 % of organisms in 3-7 days
• Free from cross resistance from other organisms.
• The drug has a particular effect in relieving nasal
symptoms and healing of foot ulcers
• Dose – 600 mg once a month
20. FLUOROQUINOLONES
• Ofloxacin, Pefloxacin, Sparfloxacin, Moxifloxacin
• BACTERICIDAL & highly effective
• 22 doses of Ofloxacin ( 400mg/day) - killed 99.99%
• Used as an alternate drug
21. • Only macrolide having significant activity against M.
Leprae
• Clarithromycin is less BACTERICIDAL than Rifampicin.
• 500mg /day in Lepromatous Leprosy patients killed
99.9% bacteria in 8 WEEKS
• Included in alternative regimens
CLARITHROMYCINCLARITHROMYCIN
22. • Semisynthetic derivative of tetracycline
• High lipophilicity
• Bactericidal
MINOCYCLINE
BACTERICIDAL ACTION
Rifampicin > Minocycline > Clarithromycin
23. Classification of Leprosy
Tuberculoid leprosy
• Anaesthetic patch
• CMI is normal
• Lepromin test positive
• Bacilli rarely found in
biopsies
• Prolonged remissions with
periodic exacerbation
Lepromatous leprosy
• Diffuse skin & mucus
membrane infiltration &
nodules
• Deficient
• Negative
• Skin & mucus membrane
lesions bacilli +
• Progresses to anesthesia of
distal parts, atrophy,
ulceration, absorption of
digits
24. Classification of Leprosy
Paucibacillary leprosy
• 1-5 skin lesions
• No nerve or only 1 nerve
involvement
• Skin smear is negative at all
sites
• TT & BT
Multibacillary leprosy
• 6 or more skin lesions
• > 1 nerve involvement
• Negative
• Skin smear positive at any
one site
• LL, BL, BB
26. Alternative regimens for leprosy
• Intermittent ROM
• Intermittent RMMx
• Ofloxacin or minocycline can be used in place
of clofazimine (if pt refuses Clofazimine)
• 4 drug therapy
– Rifampicin 600 mg + sparfloxacin 200 mg +
clarithromycin 500 mg + Minocycline 100 mg daily
for 12 weeks
27. Treatment : Corticosteroids
Cutaneous ulcerations,multiple
nerve involvement
Type IV Hypersensitivity
(Delayed hypersensitivity response)
TYPE 1 /
REVERSAL REACTIONS
Treatment :
Clofazamine,corticosteroids,
Thalidomide
Existing lesions enlarge ,
become red, inflamed and
painful
Type III Hypersensitivity
(Humoral antibody response)
TYPE2 / ERYTHEMA
NODOSUM LEPROSUM
LEPRA REACTIONS
Lepra ReactionsDAPSONE
28. REACTION PREDNISOLONE CLOFAZAMINE THALIDOMIDE
Reversal
reaction
(Type 1)
up to 1 mg/kg/d
then gradually
reduced
Erythema
Nodosum
Leprosum
(Type 2)
up to 1 mg/kg/d
then gradually
reduced
up to 300 mg up to 400 mg
• Maximum daily dose is shown when single use
• Combination therapy is recommended in ENL
Treatment of Lepra ReactionsDAPSONE
29. Drugs used for the Management of Reactions
• Thalidomide
• Corticosteroids
• Chloroquine
• Clofazamine
• NSAIDS
30. Summary
• Drugs for leprosy
• MDT for leprosy
• Type 1 lepra reaction
• Type 2 lepra reaction