Which four medications are standardly prescribed for active tuberculosis?

• A. Rifampin, Isoniazid, Pyrazinamide, Ethambutol
• B. Rifampin, Isoniazid, Ethambutol, Amoxicillin
• C. Isoniazid, Rifampin, Pyrazinamide, Ciprofloxacin
• D. Ethambutol, Pyrazinamide, Streptomycin, Rifampin

Answer: (A)

The main idea here is that treating active tuberculosis reliably starts with a four-drug, first-line regimen to prevent resistance and effectively kill the bacteria. The four drugs used together are rifampin, isoniazid, pyrazinamide, and ethambutol—often remembered as RIPE therapy. Each drug brings a different action: isoniazid blocks synthesis of the mycobacterial cell wall; rifampin stops RNA synthesis; pyrazinamide disrupts bacterial energy production, especially in acidic environments; ethambutol interferes with cell wall formation. Using them in combination maximizes bacterial kill and minimizes the chance that resistant strains will emerge.

The other options mix in drugs not part of the standard initial four-drug regimen for drug-susceptible TB. Amoxicillin isn’t used for TB; ciprofloxacin may be used in drug-resistant TB or when first-line agents can’t be used, but it isn’t part of the standard initial four-drug plan; streptomycin is an older injectable agent and not part of the typical first-line four-drug induction.