Antimycobacterial

Antimycobacterial refers to medicines that inhibit the growth of mycobacteria, a genus of bacteria that includes the pathogens Mycobacterium tuberculosis and Mycobacterium leprae as well as numerous non-tuberculous species. These agents are used to treat tuberculosis, latent TB infection, leprosy, and infections caused by non-tuberculous mycobacteria. Treatment regimens typically combine multiple antimycobacterial drugs over extended periods to prevent resistance.

Drug classes and examples: First-line TB drugs include isoniazid, rifampin (rifampicin), pyrazinamide, and ethambutol. Isoniazid blocks mycolic acid synthesis; rifampin inhibits bacterial RNA polymerase; pyrazinamide disrupts energy production; ethambutol impairs cell wall synthesis. Second-line and newer agents include fluoroquinolones (moxifloxacin, levofloxacin), injectable aminoglycosides (streptomycin, amikacin), ethionamide, cycloserine, para-aminosalicylic acid, linezolid, bedaquiline, delamanid, and pretomanid. For non-tuberculous mycobacterial disease, macrolides (clarithromycin, azithromycin) and other agents are used based on species and susceptibility.

Resistance and safety: Mycobacterial resistance arises through genetic mutations; treatment relies on combinations and adherence. Rifamycins induce hepatic enzymes and interact with many drugs. Common adverse effects include hepatotoxicity (isoniazid, pyrazinamide, rifampin), peripheral neuropathy (isoniazid), optic neuritis (ethambutol), hyperuricemia (pyrazinamide), and QT prolongation (bedaquiline, delamanid). Drug susceptibility testing guides regimen selection, and therapy is often coordinated with HIV care due to drug interactions and co-infection risk.