Red color urine is caused by which anti-tubercular drug?

NORCET 1 - 2020

Pharmacology

Easy

Appeared in: NORCET 1 - 2020

Explanation

Rifampicin is a first-line anti-tubercular drug.
A well-known and harmless side effect of Rifampicin is the red-orange discoloration of body fluids, including urine, tears, sweat, and saliva.
This color change is due to the drug's chromophoric (color-producing) properties and its excretion pathway.
Nurses should educate patients about this expected side effect to prevent anxiety and ensure treatment adherence.

Option A: Isoniazid's primary adverse effects are peripheral neuritis (nerve damage) and hepatotoxicity (liver damage). It does not change the color of urine to red.
Option C: Streptomycin is an aminoglycoside antibiotic whose major toxicities are ototoxicity (hearing and balance problems) and nephrotoxicity (kidney damage).
Option D: Ethambutol is known for causing optic neuritis, which manifests as decreased visual acuity and difficulty in red-green color discrimination.

Visual 1: Infographic: Chart of first-line anti-TB drugs (Rifampicin, Isoniazid, Pyrazinamide, Ethambutol) detailing their mechanism of action, key side effects, and essential nursing considerations for each.

Clinical Relevance

Nursing practice connection: Knowing Pharmacology: Side effects of anti-tubercular drugs helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Patient education is a critical nursing responsibility. When initiating Rifampicin, always inform the patient about the harmless red-orange discoloration of body fluids to prevent alarm and non-adherence. Also, advise patients who wear soft contact lenses to switch to glasses, as the lenses can be permanently stained.
Monitoring for adverse effects is crucial for all anti-TB drugs. While the color change from Rifampicin is benign, the hepatotoxicity of Rifampicin, Isoniazid, and Pyrazinamide, the neurotoxicity of Isoniazid, and the optic neuritis from Ethambutol are serious and require regular monitoring.
What if? If a patient on Rifampicin reports dark, tea-colored urine along with yellowing of the skin or eyes (jaundice), this is a red flag for hepatotoxicity, not the expected red-orange discoloration. The nurse must instruct the patient to stop the medication and seek immediate medical attention for liver function testing.

How to Approach the Question

Identify the core question: The question asks for the specific anti-tubercular drug that causes red-colored urine.
This is a factual recall question based on pharmacology knowledge.
Mentally review the common side effects of the main anti-tubercular drugs: Isoniazid, Rifampicin, Pyrazinamide, and Ethambutol.
Recall the mnemonic 'RIPE' for first-line drugs and their key side effects.
Associate 'R' for Rifampicin with 'R' for Red/orange discoloration of body fluids.
Evaluate the other options to confirm they are incorrect. Isoniazid causes neuropathy, Streptomycin causes ototoxicity/nephrotoxicity, and Ethambutol causes optic neuritis.

Concept Tested & Keywords

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