This document summarizes information about leprosy (Hansen's disease), including:
1. It is caused by Mycobacterium leprae bacteria and primarily affects the skin, nerves, and mucous membranes.
2. There are different classifications of leprosy based on immune response and symptoms, including paucibacillary (few bacteria) and multibacillary (many bacteria) forms.
3. Leprosy is now curable using multidrug therapy regimens of 6 months to 1 year depending on classification, helping to reduce cases from 12 million to 2.7 million.
1. Dr. D. K. Brahma
Associate Professor
Department of Pharmacology
NEIGRIHMS, Shillong
2. Leprosy is caused by a slow-growing type of
bacteria called Mycobacterium leprae (M. leprae)
Also known as Hansen's disease, after the scientist
who discovered M. leprae in 1873 - Dr. Gerhard
Henrik Armauer Hansen of Norway
Bears social stigma
It primarily affects the skin, mucous membrane
and the peripheral nerves
Long Incubation period (3 – 5 years)
Curable now – deformities/defects – may not
reverse
4. The simplest, oldest, cheapest, most active and most commonly
used
Diamino diphenyl sulfone (DDS)
MOA:
Leprostatic even at low concentration – higher conc. Arrests growth of
may other bacteria
Chemically related to Sulfonamides – same mechanism – inhibition of
incorporation of PABA into folic acid (folic acid synthase)
Specificity to M leprae – affinity for folate synthase
Doses for acute infection – too toxic
Activity:
Used alone – resistance – MDT needed
Resistance – Primary and Secondary (mutation of folate synthase – lower
affinity)
2.5% to 40% Vs 20% Resistance
However, 100 mg/day – high MIC -500 times and continued to be effective
to low and moderately resistant Bacilli (low % of resistant patient)
Persisters. Also has antiprotozoal action (Falciparum and T. gondii)
5. Pharmacokinetics:
Complete oral absorption and high distribution (less CNS
penetration)
70% bound to plasma protein – concentrated in Skin, liver,
muscle and kidney
Acetylated and glucoronidae and sulfate conjugated –
enterohepatic circulation
Half life 24-36 Hrs, but cumulative (1 – 2 weeks)
ADRs: Generally Well tolerated drug (100 mg /day)
Haemolytic anaemia (oxidizing property) - G-6-PD are more
susceptible
Gastric - intolerance, nausea, gastritis
Methaemoglobinaemia, paresthesia, headache, mental
symptoms and drug fever
Allergic rashes, FDE, phototoxicity, exfoliative dermatitis and
hepatotoxicity etc.
6. Sulfone syndrome: Starts after 4- 6 weeks of
therapy, more common with MDT
Symptoms: Fever, malaise, lymph node enlargement,
desquamation of skin, jaundice and anemia –
malnourished patients
Management: stopping of Dapsone in severe
cases, corticosteroid therapy
Corticosteroids (prednisolone 40 – 60 mg/day) –
severe cases – till reaction controlled – tapered over
8-12 weeks
Dapsone contraindications: Severe anaemia
and G-6-PD deficiency and hypersensitivity
7. A dye - Leprostatic and anti-inflammatory
MOA: Interferes with template function of DNA in M.
leparae
Activity: Used alone resistance (1 -3 years) – but Dapsone
resistance cases responds in 2 months (lag period)
Kinetics: orally effective – accumulates in fat in crystalline
form – entry to CSF poor – half life 70 days
Used as component of MDT
ADRs: - well tolerated
Reddish-black discolouration of skin – exposed parts
Discolouration of hair and body secretions, dryness of skin and
itching, acneform eruptions and phototoxicity – conjunctival
pigmentation
GI symptoms: Enteritis with intermittent loose stool, abdominal
pain, anorexia and weight loss – early and late symptoms
Should be avoided in pregnancy and liver & kidney disease
8. Rifampicin: Cidal. 99.99% killed in 3-7 days, skin
symptoms regress within 2 months
Not satisfactory if used alone – persisters even prolonged
treatment
Included in MDT to shorten the duration of treatment
and also to prevent resistance
Not toxic and no induction of hepatic enzyme - dose as
single dose only
Should not be used in ENL and Reversal phenomenon
Ofloxacin: all fluoroquinolones except
ciprofloxacin are active. Used as alternative to
Rifampicin – 22 daily doses
Minocycline: Lipophillic - enters M leprae. Less
marked effect than Rifampicin
9. Granulomatous infection – skin,, mucous membrane
and nerves
Systems of Classification:
1st (Based on immune system of the patient): Mainly two types:
lepromatous (sore on skin, nerves, and other organs) and
tuberculoid (sore on skin)
2nd (Ridley-Jopling system – based on symptoms): Borderline
tuberculoid leprosy (BL), Borderline lepromatous (BL),
Borderline leprosy (BB) and Intermediate leprosy (I)
For operational purposes: WHO
Paucibacillary (>5 lesions): few bacilli and noninfectious – TT
and BT and I
Multibacillary (<5 lesions): large bacilli load and infectious –
LL, BL and BB types
Single lesion Paucibacillary: single lesion
10. Paucibacillary (PB) - TT and BT
and I
Multibacillary (MB) - LL, BL and
BB
• 1- 5 skin lesions
• No nerve/only one nerve
involvement +/- 1-5 skin lesions
• Skin smear negative at all sites
• 6 or more skin lesions
• More than one nerve involved
irrespective of skin lesions
• Skin smear positive at any one of
the sites
11. Initially (1982) – PBL Dapsone + Rifampicin for
6 Months and MBL – Dapsone + Rifampicin +
Clofazimine – 2 years or till disease
inactivity/smear negative – with added 5 years
surveillance for MBL cases
However, 12 years study (in 1994) – fixed
duration for 6 months and 2 years was
recommended – 12 million to 2.7 million and
no resistance
In 1999 – 6 months and 1 year recommended
12. Drug Paucibacillary (PB) Multibacillary (MB)
Rifampicin 600 mg once a month
Supervised
600 mg once a month
Supervised
Dapsone 100 mg daily self
administered
100 mg daily self
administered
Clofazimine - 300 mg once a month
Supervised
50 mg daily self administered
Duration 6 Months 12 Months
13. Photo Courtesy: Dr. Anju R. Marak,
SM&HO cum DLO and DMO-MCH,
Ri-Bhoi District, Meghalaya
14. 1. Lepra Reaction Occurs in LL type (Type – III HSR) – coincides
with institution of chemotherapy or intercurrent infection
Arthus type of reaction – release of antigens from killed bacilli - may be
mild, moderate and severe (ENL)
Symptoms: enlarged lesions, become red (inflamed nodules and papules)
and painful, new lesions – fever and other constitutional symptoms
Treatment:
Mild analgesics
Mild: Clofazimine - 200 mg daily
Moderate to severe-Steroids: 60 mg/day-Prednisolone - taper off in 2-3 months
2. Reversal reaction Occurs in TT and BL cases (Type II HSR) –
delayed hypersensitivity to M. leprae antigens
• Symptoms: Cutaneous ulceration, multiple nerve involvement with
swollen and tender nerves – occurs suddenly even after completion of
therapy …… Treatment: same as above
17. “The biggest disease today is not leprosy
or tuberculosis, but rather the feeling of
being unwanted, uncared for, and
deserted by everybody.” – Mother Teresa
Thank you