Which statement accurately describes why a four-drug regimen is prescribed for active tuberculosis?

• A. The regimen is short-term and requires minimal adherence
• B. The combination of drugs is necessary to decrease the risk of drug resistance
• C. TB can be cured with a single drug
• D. Drugs should be stopped when symptoms improve

Answer: (B)

Treating active TB with a four-drug regimen is essential to prevent drug resistance. TB bacteria can mutate and survive when only one medicine is used, especially given their slow growth and the way they hide in body tissues. Using multiple drugs with different actions attacks the bacteria in several ways at once, making it far less likely that any surviving bacteria will be resistant to all of them. This approach also helps ensure that bacteria in different parts of the body and in dormant states are killed. Because stopping treatment early or waiting for symptoms to improve can leave behind resistant organisms and lead to relapse, the full, multi-drug course is necessary.