Which of the following is NOT a first-line anti-TB drug?

Amikacin is not classified as a first-line anti-TB drug; it is actually an aminoglycoside antibiotic that is typically used as a second-line treatment for tuberculosis. First-line anti-TB medications include Isoniazid, Rifampicin, and Streptomycin, which form the cornerstone of tuberculosis treatment due to their effectiveness and relatively favorable side effect profiles.

Isoniazid and Rifampicin are essential in any first-line regimen for active tuberculosis because they specifically target the bacteria causing the disease. Streptomycin, while not as commonly used today due to resistance and side effects, is still recognized as part of the standard initial treatment options. In contrast, Amikacin is reserved for situations where there are complications such as drug resistance, which is why it does not belong in the first-line category. This classification is important for ensuring that patients receive the most effective and appropriate therapy based on the type and severity of tuberculosis they have.