Drugs Used In Tuberculosis

e Therapykills both extracellular and intracellular bacteria. It
A significant advancement in the treatment ofinterferes with the cell wall (mycolic acid) synthesis of
tuberculosis has taken place in recent years. Thethe bacteria. It is the best drug for treatment of
development of resistance to drugs is prevented bytuberculosis with respect to efficacy, safety, cost,
using two or more drugs. The long duration ofease of administration, and patient acceptance. It
treatment (1 to 2 years) has been shortened by themay be administered alone for prophylaxis, or in
introduction of short course chemotherapy. Thecombination with other drugs for chemotherapy, of
problem of poor compliance to drugs is minimised bydisease. It is almost always required for combination
the introduction of intermittent supervised therapytreatment in DOTS.
called DOTS (Directly Observed Treatment ShortAdverse Effects: It increases excretion of vitamin B6
Course) under revised National Tuberculosis Control(pyridoxine) which may result in numbness, pain,
Programme. Three types of treatment regimenstiredness, weakness, pain in the muscles and joints.
used are described below:Patients suffering from diabetes mellitus, malnutrition,
Conventional Course Chemotherapy: This consists ofor alcoholism should be given 10 mg pyridoxine
streptomycin, INH and thiacetazone or ethambutolroutinely, If there are pre-existing symptoms of
for 12-18 months. However since failure rates areperipheral neuritis, a larger dose of pyridoxine of 50
high, and compliance poor, it is not recommendedto 100 mg may be given daily. Other adverse effects
nowadays.are liver damage, mental disturbance and rarely fits.
Short Course Chemotherapy: A 6 to 9 monthLiver damage is not common in children but may
regimen consisting of isoniazid, rifampicin, ethambutol,occur in elderly and alcoholics.
and pyrazinamide daily for 2 to 3 months, followedPrecautions
by isoniazid and rifampicin daily for 4-6 months, hasThe doctor should be informed if any symptoms of
been found to be satisfactory, provided that it isperipheral neuritis such as a decreased sensation or
fullysupervised. The patient s disease is catagorizedpain in the muscles occur.
depending on the extent of disease. The treatmentA liver function test (serum transaminase) is advised
is carried out in two phases. In the initial phase fourafter a month or two of the treatment. If the serum
drugs are to be taken daily, or thrice weekly, for 2transaminase exceeds 3 times normal value, the drug
months. Then sputum examination is done. If it isshould be stopped.
positive for TB organisms, drugs are continued forA pyridoxine supplement is necessary in pregnant
another month. In the second phase or thewomen, nursing mothers, and infants as this drug is
continuation phase, two or three drugs are to besecreted in milk.
taken for 6 to 8 months.The doctor should be consulted if any adverse
Drugseffects like allergic reactions, arthritis, or difficulty in
The drugs used in the treatment of tuberculosis canvision occur.
be divided into first and second line drugs. Foods suchThe drug should be taken regularly as advised by the
as meat, milk, cereals, legumes, and yeast are rich indoctor. Inadequate doses or missing the drug in
vitamin B6 . A diet containing these may help inbetween may cause a relapse.
preventing peripheral neuritis.If nausea occurs, the drug should be taken with
First Line Drugsmeals, dividing the dose into two halves, that is, half
Isoniazid (Isonex)in the morning and half in the evening.
Isoniazid is a first line drug. It is a bactericidal drug and