What is the standard initial treatment for active tuberculosis?

• A. Isoniazid monotherapy for 9 months
• B. Rifampin for 12 months
• C. RIPE therapy for 6 months
• D. Pyrazinamide only for 6 months

Answer: (C)

Active TB requires combination therapy to prevent the bacillus from developing resistance and to target bacteria in different states of growth. The standard initial approach is four drugs—rifampin, isoniazid, pyrazinamide, and ethambutol—for the first two months (the intensive phase), followed by continuation with rifampin and isoniazid for the next four months, totaling about six months.

Rifampin and isoniazid are the backbone of treatment because they are strongly bactericidal against actively replicating TB. Pyrazinamide works well against semi-dormant bacilli in acidic environments and helps shorten therapy. Ethambutol adds protection against resistance until susceptibility results confirm that the isolate is susceptible to isoniazid and rifampin; if confirmed, ethambutol can often be stopped.

Using a single drug, such as isoniazid alone or rifampin alone for a prolonged period, would allow resistant TB to emerge, which is why monotherapy or prolonged mono-drug regimens are not used. A regimen with only pyrazinamide or only one drug would not effectively eradicate the infection.

So, the best answer reflects the standard four-drug intensive phase followed by four months of two-drug continuation, for a total of six months.