Which of these drugs is nephrotoxic?

DSSSB Public Health Nurse - 2015

Pharmacology

Easy

Appeared in: DSSSB Public Health Nurse - 2015

Explanation

Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) are directly nephrotoxic, meaning they can cause damage to the kidneys.
The primary mechanism of injury is the inhibition of renal prostaglandins, which are crucial for maintaining adequate blood flow to the kidneys.
This inhibition leads to constriction of the afferent arterioles, reducing glomerular perfusion and potentially causing acute kidney injury (AKI).
Chronic use or use in at-risk individuals can lead to conditions such as acute interstitial nephritis and papillary necrosis.

Option A: Diuretics are not directly nephrotoxic. They can lead to pre-renal acute kidney injury by causing excessive fluid loss (volume depletion) and electrolyte imbalances, but they do not cause direct cellular damage to the kidney.
Option B: ACE inhibitors are generally considered reno-protective, especially in patients with diabetes and hypertension. While they can cause a decrease in GFR in specific situations (like bilateral renal artery stenosis) by dilating the efferent arteriole, they are not classified as directly nephrotoxic.
Option D: Sodium bicarbonate and potassium bicarbonate are not nephrotoxic. In fact, sodium bicarbonate is often administered to patients with chronic kidney disease to correct metabolic acidosis.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Drug-induced nephrotoxicity as background academic context rather than a clinical decision trigger.
Nurses must educate patients, especially those with hypertension, heart failure, or pre-existing kidney disease, about the risks of over-the-counter NSAID use.
It is a critical nursing responsibility to monitor renal function (serum creatinine, BUN, and urine output) in hospitalized patients receiving NSAIDs, particularly when combined with other potentially nephrotoxic drugs.
What if? If a patient with known chronic kidney disease (CKD) is also taking an ACE inhibitor and develops a fever and body aches, the nurse should strongly advise against using an NSAID like ibuprofen. The combination of CKD, ACE inhibitor use, and potential dehydration from fever significantly increases the risk of acute kidney injury from NSAIDs. A safer alternative like acetaminophen should be recommended.

How to Approach the Question

First, identify the key term in the question: 'nephrotoxic', which means toxic or damaging to the kidneys.
Next, review each drug class in the options and recall its primary mechanism of action and major side effects, specifically focusing on renal effects.
Evaluate Diuretics: They primarily affect fluid and electrolyte balance. While this can impact kidney function, it's an indirect effect.
Evaluate ACE inhibitors: Recall that they are often used to protect the kidneys in chronic disease by reducing pressure within the glomerulus.
Evaluate NSAIDs: Remember their common mechanism of inhibiting prostaglandins. Connect this to the role of prostaglandins in maintaining renal blood flow. This link identifies them as directly nephrotoxic.
Evaluate Bicarbonates: These are electrolytes/buffers and are not associated with kidney toxicity.

Concept Tested & Keywords

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