Antitubercular Agents

Antitubercular Agents

INTRODUCTION

Tuberculosis is the most prevalent infectious disease worldwide and a leading killer caused by a single infectious agent, that is, Mycobacterium tuberculosis. According to World Health Organization (WHO) report, M. tuberculosis, currently infects over 2 billion people worldwide, with 30 million new cases reported every year. This intracellular infection accounts for at least 3 million deaths annually. Common infection sites of the tuberculosis are lungs (primary site), brain, bone, liver, and kidney. The main symptoms are cough, tachycardia, cyanosis, and respiratory failure. Depending upon the site of infection, the disease can be categorized as follows:

·Pulmonary tuberculosis (respiratory tract).

·Genitourinary tuberculosis (genitourinary tract).

·Tuberculous meningitis (nervous system).

·Miliary tuberculosis (a widespread infection).

Drugs used in the treatment of tuberculosis can be divided into two major categories (Fig. 4.1):

1. First-line drugs: Isoniazid, streptomycin, rifampicin, ethambutol, and pyrazinamide.

2. Second-line drugs: Ethionamide, p-amino salicylic acid, ofloxacin, ciprofloxacin, cycloserine, amikacin, kanamycin, viomycin, and capreomycin.

The majority of the patients with tuberculosis are treated with first-line drugs and shows excellent results with a 6-month course of treatment. For the first 2 months, isoniazid, rifampicin, and pyrazinamide are given, followed by isoniazid and rifampicin for the remaining 4 months. Second-line drugs are used mainly to treat multidrug resistant M. tuberculosis infections.