In a patient with tuberculosis, physician will prescribe?

Appeared in: BSF Staff Nurse - 2015

Explanation

Isoniazid (INH) is a first-line, bactericidal drug specifically used for treating tuberculosis.
It is a core component of the standard multi-drug therapy regimen (RIPE: Rifampin, Isoniazid, Pyrazinamide, Ethambutol) for drug-susceptible TB.
Isoniazid works by inhibiting the synthesis of mycolic acid, a crucial component of the mycobacterial cell wall, leading to bacterial death.
Due to its high efficacy and low cost, it is one of the most widely used antitubercular agents worldwide.

Option A: Penicillin is a beta-lactam antibiotic that is ineffective against Mycobacterium tuberculosis. The mycobacterial cell wall is rich in lipids (mycolic acid) and lacks the peptidoglycan structure that penicillin targets.
Option C: Azithromycin is a macrolide antibiotic that is not used as a primary treatment for M. tuberculosis infection.
Option D: Codeine is an opioid antitussive used for symptomatic relief of cough. It does not have any antimicrobial properties and does not treat the underlying cause of tuberculosis.

Clinical Relevance

Nursing practice connection: Use the key finding related to Pharmacological management of Tuberculosis (TB) to guide bedside assessment, documentation, and the next nursing action.
The cornerstone of TB treatment is multi-drug therapy to prevent the emergence of resistant strains. Adherence to the long treatment course (6 months or more) is critical for a cure.
Nurses play a vital role in patient education regarding medication adherence, potential side effects (especially liver toxicity with INH, Rifampin, and Pyrazinamide), and infection control measures.
Directly Observed Therapy, Short-course (DOTS) is a key public health strategy recommended by the WHO to ensure patients complete their treatment, thereby improving cure rates and reducing the spread of TB.

How to Approach the Question

Identify the core of the question: It asks for a medication used to treat tuberculosis.
Recall the standard first-line drugs for TB. A helpful mnemonic is RIPE: Rifampin, Isoniazid, Pyrazinamide, and Ethambutol.
Scan the options to see if any of the RIPE drugs are listed.
Recognize that 'Isoniazid' is one of the primary first-line drugs for TB.
Briefly consider the other options to confirm they are incorrect. Penicillin targets a different cell wall type. Azithromycin is for atypical mycobacteria. Codeine only treats symptoms (cough).
Conclude that Isoniazid is the only correct choice for treating the TB infection itself.

Concept Tested & Keywords

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E6 Pharmacology Nurses Shanbhag 3e p. 312-314

E6 Medicine Harrison 22e Part 1 p. 1463-1465

E6 Pharmacology Katzung 16e p. 1309-1311

Practise the full BSF Staff Nurse - 2015

Attempt every question from this paper in a timed mock, then review the full solution for each one.