Tuberculosis is an infectious disease caused by the bacterium Mycobacterium tuberculosis, which most commonly affects the lungs. It spreads through the air when people with active TB cough, sneeze or talk. Common symptoms include cough, fever, night sweats and weight loss. Diagnosis involves chest x-rays and microbiological tests. Treatment requires taking several antibiotics over many months to prevent drug resistance, and involves both intensive and continuation phases. Drug-resistant TB like MDR-TB is more difficult to treat and requires alternative drug combinations for over 24 months. The only available vaccine is BCG.
2. WHAT IS TUBERCULOSIS
ο infectious disease caused by various strains of mycobacteria,
usually Mycobacterium tuberculosis. ( gram positive bacteria)
ο It is a chronic granulomatous disease.
ο Tuberculosis typically attacks the lungs, but can also affect
other parts of the body. It is spread through the air when
people who have an active TB infection cough, sneeze, or
otherwise transmit respiratory fluids through the air.
3. ο The classic symptoms of active TB infection are a chronic
cough with blood-tinged sputum, fever, night sweats,
and weight loss . Infection of other organs causes a wide range
of symptoms.
5. SIGNS AND SYMPTOMS
ο most commonly occurs in the lungs (known as pulmonary
tuberculosis).Extrapulmonary TB occurs when tuberculosis
develops outside of the lungs, although extra pulmonary TB
may coexist with pulmonary TB as well.
ο fever, chills, night sweats, loss of appetite, weight loss,
and fatigue.[9] Significant finger clubbing.
6. Pulmonary
ο it most commonly involves the lungs (in about 90% of cases).
ο Symptoms may include chest pain and a prolonged cough
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producing sputum. About 25% of people may not have any
symptoms (i.e. they remain "asymptomatic").
Occasionally, people may cough up blood in small amounts, and
in very rare cases, the infection may erode into thepulmonary
artery, resulting in massive bleeding (Rasmussen's aneurysm).
Tuberculosis may become a chronic illness and cause extensive
scarring in the upper lobes of the lungs. The upper lung lobes are
more frequently affected by tuberculosis than the lower ones.
The reason for this difference is not entirely clear.
It may be due either to better air flow, or to poor lymph drainage
within the upper lungs.
7. Extrapulmonary
ο n 15β20% of active cases, the infection spreads outside the lungs,
causing other kinds of TB.
ο Extrapulmonary TB occurs more commonly
in immunosuppressed persons and young children. In those with HIV,
this occurs in more than 50% of cases.
ο Notable extrapulmonary infection sites include the pleura (in
tuberculous pleurisy), the central nervous system (in
tuberculous meningitis), the lymphatic system (inscrofula of the neck),
the genitourinary system (in urogenital tuberculosis), and the bones and
joints (in Pott's disease of the spine), among others. When it spreads to
the bones, it is also known as "osseous tuberculosis".
ο a form of osteomyelitis. Sometimes, bursting of a tubercular abscess
through skin results in tuberculous ulcer. An ulcer originating from
nearby infected lymph nodes is painless.
8. ο Transmission: air born disease , When people with active
pulmonary TB cough, sneeze, speak, sing, or spit, they expel
infectious aerosol droplets 0.5 to 5.0 Β΅m in diameter. A single
sneeze can release up to 40,000 droplets.
ο Pathogenesis:TB infection begins when the mycobacteria
reach the pulmonary alveoli,
9. ο WHO expert gp has farmed clear cut treatment guidelines
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for different categories of TB patient
The dose of drug std on the basis of body weight.
The regimens have two phase
Inititial intensive phase: lasting 2 3 month ,amied to rapidly
kill the TB bacilli
Continuation phase : lasting for 4-6 months ,estimated bacilli
relapse dose not occur
10. Category wise treatment regimens
ο Category 1: untreated T.B
ο CATEGORY 2: RELAPSE, INTERRUPTED TREATMENT
ο CATEGORY3: LESS SEVERE FORMS OF
EXTRAPULMONRY T.B
ο CATEGORY 4: THESE ARE CHRONIC CASE WHO HAVE
REMAINED OR HAVE BECOME +VE AFTER
COMPLETING FULLY SUPERVISED RETREATMENT
REGIMEN.
11. How is TB treated?
ο Several antibiotics need to be taken over a number of months to
prevent resistance developing to the TB drugs. The great majority
of TB bacteria are sensitive to the antibiotics used.
ο 1st line drug : have high antitubercular efficacy,low toxicity
ο 2nd line drug: low antitubercular effficacy ,low toxicity
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Name of antibiotic used:
Cycloserine
Ethambutol
Ethiona mide
Isoniazid
Protionamide
13. ο Pyrazinamide
ο Rifampicin
ο Dapsone
ο Discription of antibiotic used:
ο Cycloserine: 2nd line drug
ο Max: 1 gm in day
ο Interaction:
ο B12 ,FOLIC ACID DEFIciency, inhibit s phenytoin metabolism
& may increase of risk of epileptic seizuers, alcohal increase of
convulsions, increase cns toxicity.
ο ADR: megaloblastic anaemia, convulsions (dose related)
ο Drowsiness, vertigo, depression.
14. ο ETHAMBUTOL:1st line drug
ο Max dose: 15mg/kg/day
ο Interaction: synergistic effect wd other antitubercular agent
ο ADR: reduced renal clearance of urates.
ο GI disturbence
ο ETHIONAMIDE: 2nd line drug
ο Max dose: 1gm/day
ο Interaction: increase hepatotoxicity wd rifampicin, increase
cns toxicity wd cycloserine
ο ADR: ANOREXIA, excessive salivation, metallic TASTE,
15. ο ISONIAZID: 1st line drug
ο Max dose: 300 mg daily
ο Interaction: may increase toxicity of carbamazepine
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,ethosuximide, phenytoin, diazepam, triazolam, theophylline,
clofazimine,warferine.
ADR: peripheral neuritis ,optic neuritis, psychotic reaction
Protionamide: 2ND LINE drug
Max dose: 1gm daily
Interaction: increase neurotoxic effect wd cycloserine,
increase hepatotoxicity wd rifampicin
ADR: thrombocytopenia, gyanecomastia , stomatitis
16. ο Pyzinamide: multi drug regimen
ο 1st LINE DRUG
ο Max dose: 3gm DAILY
ο INTERACTION: excretion may be blocked by probencid
ο ADR : hyperureicaemia
ο Rifampicin:
ο 1ST line drug
ο Max dose : 600 mg /day
ο Interaction: absorption may be decrease when taken wd
antacids, opioid, ketokonazole,
ο ADR: Abnormalities of liver , influenza like symptoms, reddish
colors urine.
17. Multi drug therapy
& combinations of drugs
ο ISONIAZID+ETHAMBUTOL
ο RIFAMPICIN+ISONIAZID
ο RIFAMPICIN+ ISONIAZID+PYRAZINAMIDE
ο RIFAMPICIN+ISONIAZID+PYRAZINAMIDE+ETHAMB
UTOL
ο OTHER ANTI T.B AGENT: DAPSONE,
CIPROFLOXACIN.
18. MULTIDRUG RESISTANT (MDR) T.B
ο RESISTANCE TO BOTH ISONIAZID AND RIFAMPIN
ο MDR TB has a more rapid course ( some die in 4-16 weeks)
ο 1st nd 2nd line drug are given for 12 to 24 months
ο Regimen of dose depend on associated disease
ο For isonizid resistance: rifampin
,pyrozinamide,ethambutol given 12 months
ο For isoniazid +rifampin resistance:
pyrazinamide+ethambutol,+streptomycin/kmc/amic/cpro/
ofl/can be used.
20. ο Treatment in pregnant women:
isoniazid,ripampin,pyrazinamide to safe for foetus
ο (2HRZ+4HR) RECOMMMENTED FOR STD 6 MONTHS
ο SOMETIMES Z CREATE TERATOGENICITY EFFECT