Red-orange urine indicates side effects of?

NIMHANS Nursing Officer - 2021

Pharmacology

Easy

Appeared in: NIMHANS Nursing Officer - 2021

Explanation

Rifampicin is a first-line anti-tuberculosis antibiotic known for causing a distinct, though harmless, red-orange discoloration of body fluids.
This effect applies to urine, sweat, tears, and saliva and is an expected outcome of the therapy.
The key differentiator is that this specific color change is a unique and classic side effect of Rifampicin, distinguishing it from other anti-TB drugs.

Option A: Pyrazinamide's primary adverse effects are hepatotoxicity and hyperuricemia, which can precipitate gout. It does not cause red-orange urine.
Option C: Isoniazid is mainly associated with peripheral neuropathy (nerve damage) and hepatotoxicity. It does not change the color of urine to red-orange.
Option D: Ethambutol's most significant side effect is optic neuritis, which can lead to decreased visual acuity and difficulty distinguishing between red and green colors.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Side effects of first-line anti-tuberculosis medications as background academic context rather than a clinical decision trigger.
Patient education is a critical nursing responsibility. Nurses must inform patients taking Rifampicin about the expected color change to prevent anxiety and ensure treatment adherence, as the patient might otherwise stop the medication fearing something is wrong.
Rifampicin is a potent inducer of cytochrome P450 enzymes, which accelerates the metabolism of many other drugs, including oral contraceptives, anticoagulants, and certain antiretrovirals. This makes medication reconciliation and counseling on alternative birth control methods a key safety intervention.
What if? If a patient on a RIPE regimen reports blurred vision and difficulty distinguishing colors, the nurse's priority concern should shift to Ethambutol-induced optic neuritis, not Rifampicin. This would require immediate reporting to the physician for a potential change in therapy.

How to Approach the Question

This is a factual recall question testing knowledge of pharmacology.
Identify the key clinical sign presented in the question stem: 'Red-orange urine'.
Systematically review the known hallmark side effects of each anti-tuberculosis drug listed in the options.
Recall or use the mnemonic RIPE for the first-line drugs: Rifampicin, Isoniazid, Pyrazinamide, Ethambutol.
Associate the 'R' in Rifampicin with 'Red-orange' body fluids. This is a classic and frequently tested association.
Eliminate the other options based on their primary toxicities: Isoniazid (neuropathy, hepatitis), Pyrazinamide (hyperuricemia, hepatitis), and Ethambutol (optic neuritis).

Concept Tested & Keywords

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