How does multidrug-resistant tuberculosis differ from ordinary tuberculosis?

Ordinary tuberculosis is typically treated with a standard course of antimicrobial drugs, such as isoniazid and rifampicin, which can cure the disease within months.12

In contrast, multidrug-resistant tuberculosis (MDR-TB) occurs when the bacillus develops resistance to at least these two primary medications. This resistance often arises when patients do not complete their full course of treatment or are treated with an inadequate drug regimen, allowing surviving bacteria to multiply and evolve.12

While MDR-TB remains treatable, it is significantly more difficult to manage than ordinary tuberculosis. It typically requires a much longer treatment duration—often up to two years—and necessitates the use of alternative agents that are frequently associated with more severe side effects. To ensure adherence and prevent the further spread of resistant strains, health authorities often utilize directly observed therapy, where clinicians or family members monitor patients as they take their medication.1