What is the Treatment of Tuberculosis?

Tuberculosis (TB) is a potentially severe infectious disease of our lungs, which is caused by a bacterium called as Mycobacterium tuberculosis or tubercle bacillus. Typically, in human body, this bacterium targets the lungs to attack. However, these bacteria can affect any part of your body too. The tuberculosis bacteria can easily spread from any individual with TB to a normal person.
For the reason that when a TB affected patient coughs, sneezes or talks, the bacteria travels through air in tiny droplets and infects any individual with weak immune system.

Tuberculosis infographic detailing symptoms
Image via Wikipedia

Treatment of Tuberculosis

The purpose of tuberculosis treatment is not only to cure the infected patient but also to reduce the transmission of the bacteria to normal persons. Except the latent TB, the treatment of tuberculosis requires a combination therapy to cure a patient. Usually, physicians use four different antibiotics to treat tuberculosis. The duration of this treatment usually lasts form six months to one year.

Isoniazid, rifampin, ethambutol and pyrazinamide are the most commonly used antibiotics in this treatment. These drugs are also known as first line tuberculosis drugs. According to WHO (World Health Organization), the standard regimens for TB patients should be continued for six months.

Isoniazid and rifampin should be continued on a daily basis for six months.
Ethambutol and pyrazinamide should be continued on a daily basis for the first two months.

This standard treatment regimen can be followed for both Pulmonary and Extrapulmonary tuberculosis. However, sometimes patient may need to follow a 12 months course for Extrapulmonary TB.

Drugs Used in the Treatment of Tuberculosis

First Line Drugs

According to WHO, five antibiotics (Isoniazid, Rifampin, Ethambutol, Pyrazinamide and Streptomycin) are considered as the first line treatment for tuberculosis. Previously, Thioacetazone was also considered as a first line drug. However, according to WHO's update in the 4th edition of "Treatment of Tuberculosis", this drug is no longer included among the first-line drugs.

According to the American Journal of Respiratory and Critical Care Medicine (published in 2003), the ATS/CDC/IDSA (American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America) considered two new drugs (Rifabutin and Rifapentine) as first line drugs for special situations. The journal provided a new list of six drugs as first line drugs. Except streptomycin, the new list considered all the first line drugs by WHO. Streptomycin is excluded from the list due to high rates of bacterial resistance.

Internationally, a standard three-letter and a single-letter abbreviation have been used for naming all first-line anti-tuberculosis drugs.

Ethambutol is abbreviated as EMB or E, Rifampicin as RMP or R, Pyrazinamide as PZA or Z, Isoniazid as INH or H and Streptomycin as STM or S.

However, the regulatory authority of United States often uses different names and abbreviations for naming drugs. For example, rifampicin is named as rifampin and abbreviated as RIF and streptomycin is abbreviated as SM.

Second Line Drugs

Most often TB patients completely cure using the first line drugs. The second line drugs are considered as the reserved therapy for tuberculosis treatment. These drugs are often used in special conditions. When situations like resistance to first-line therapy, extensively drug-resistant tuberculosis (XDR-TB) or multidrug-resistant tuberculosis (MDR-TB) arise, the second-line drugs are implemented for the treatment of tuberculosis. Currently, six classes of second-line drugs are using for the treatment of tuberculosis.

A standard three-letter, two-letter or a single-letter and in some cases, only two or three-letter abbreviation have been used for naming second-line anti-tuberculosis drugs.

For example, Kanamycin is only abbreviated as KM, Ciprofloxacin as CIP, Amikacin as AMK, Para Aminosalicylic Acid as PAS or P.