What is the combination of drugs used in the treatment of T.B.?

MP CHO -2019 (Shift-2)

Pharmacology

Medium

Appeared in: MP CHO -2019 (Shift-2)

Explanation

The question asks for the reason behind using a combination of drugs for TB treatment.
The primary goal of combination therapy is to prevent the emergence of drug-resistant strains of Mycobacterium tuberculosis.
A large bacterial load in an infected person contains naturally occurring mutants resistant to single drugs. Using multiple drugs simultaneously ensures these resistant strains are also eliminated.
This strategy increases the likelihood of a cure, shortens the overall treatment duration, and prevents the spread of drug-resistant TB.

Option B: Checking drug sensitivity is a diagnostic process, not a therapeutic principle for using combination therapy. It is done via Drug Susceptibility Testing (DST) to determine which drugs will be effective against a specific strain.
Option C: 'Reactivity of drugs' is a vague and non-standard term in this context. The goal is not to 'check reactivity' but to achieve a therapeutic outcome.
Option D: Checking for hypersensitivity is part of patient monitoring for adverse drug reactions. It is a safety consideration, not the primary reason for prescribing a combination of drugs.

Clinical Relevance

Nursing practice connection: Knowing The rationale behind using combination drug therapy for the treatment of Tuberculosis (TB) helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Understanding the principle of combination therapy is critical for patient education. Nurses must explain to patients why taking all prescribed medications is essential to prevent treatment failure and the development of multidrug-resistant TB (MDR-TB).
Poor adherence is a major cause of drug resistance. Nurses play a key role in Directly Observed Therapy (DOTS), ensuring patients take their medication as prescribed.
Nurses must monitor for and manage the significant side effects of anti-TB drugs, such as hepatotoxicity (Isoniazid, Rifampicin, Pyrazinamide), peripheral neuropathy (Isoniazid), and optic neuritis (Ethambutol).

How to Approach the Question

First, analyze the question. Although it asks 'What is the combination...', the options are all reasons. This implies the question is actually asking 'WHY is a combination of drugs used...'.
Evaluate each option based on fundamental principles of infectious disease treatment.
Recall that TB is caused by a slow-growing bacterium that can easily develop resistance.
Option A, 'Reduce resistance', directly addresses this core problem in TB management. The high number of bacteria in an active infection means that some will be naturally resistant to any single drug.
Consider the other options. 'Checking sensitivity' (Option B) is a lab test (DST). 'Checking reactivity' (Option C) is a vague term. 'Checking hypersensitivity' (Option D) is about side effects. None of these are the primary therapeutic reason for the combination.
Conclude that preventing the emergence of resistance is the fundamental rationale for using multi-drug therapy in TB.

Concept Tested & Keywords

Concept Tested: The rationale behind using combination drug therapy for the treatment of Tuberculosis (TB).
Stem keywords: combination of drugs, treatment, T.B.
Lead-in keywords: What is
Negative lead-in flag: false

Qc6_kBoGdQudKYHoV6NwMP

E6 Pharmacology KD Tripathi Essentials 9e Part 3 p. 99-101

E6 Medicine Davidson Principles Practice 24e p. 613-615