Digitalis toxicity is indicated by?

KPSC Staff Nurse - 2016

Pharmacology

Easy

Appeared in: KPSC Staff Nurse - 2016

Explanation

Visual disturbances, specifically seeing yellow or green spots/halos around objects (a condition called xanthopsia), are a classic and specific sign of digitalis toxicity.
This distinct visual side effect occurs because the drug can affect the function of the retina and the optic nerve.
While other symptoms like nausea and bradycardia are common, the colored vision changes are a hallmark indicator that helps differentiate digitalis toxicity.

Option A: Digitalis toxicity commonly causes gastrointestinal distress, which leads to a loss of appetite (anorexia), nausea, and vomiting. An increased appetite is the opposite of the expected symptom.
Option B: The primary cardiac effect of digitalis toxicity is on the heart's rate and rhythm, typically causing bradycardia (slow heart rate) or other arrhythmias. It does not characteristically cause elevated blood pressure (hypertension).
Option C: A skin rash is not a characteristic or common sign of digitalis toxicity. It would more likely indicate an allergic reaction to the medication, which is a different type of adverse effect.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Signs and Symptoms of Digitalis Toxicity as background academic context rather than a clinical decision trigger.
Nurses must meticulously monitor patients on digitalis, especially by checking the apical pulse for a full minute before administration and holding the dose if the rate is below 60 bpm for an adult, as bradycardia is an early sign of toxicity.
The risk of toxicity is significantly increased in patients with hypokalemia (low potassium), as potassium and digoxin compete for the same binding sites on the Na+/K+-ATPase pump. Low potassium allows more digoxin to bind, increasing its effect.
What if? If a patient on digoxin has a low potassium level (e.g., 3.0 mEq/L), they can develop signs of toxicity even with a 'normal' digoxin blood level. The nurse's priority is to report the potassium level and signs of toxicity immediately, as potassium supplementation may be required.

How to Approach the Question

First, identify the core of the question: it asks for a specific indicator of 'Digitalis toxicity'.
Access your knowledge about the cardiac glycoside drug class. Recall that these drugs have a narrow therapeutic index, meaning toxicity is a common concern.
Systematically evaluate each option against the known profile of digitalis toxicity.
Option A (Increased appetite): Recall that GI upset, particularly anorexia (loss of appetite), is a very common early sign. This makes 'increased appetite' incorrect.
Option B (Elevated blood pressure): Recall that digitalis primarily affects heart rate and rhythm (contractility and conduction), not blood pressure. Bradycardia is the classic heart rate change. This makes 'elevated blood pressure' unlikely.
Option C (Skin rash): Consider if this is a primary, hallmark sign. While any drug can cause a rash, it's not a defining feature of digitalis toxicity. Eliminate it as less likely than a more specific sign.

Concept Tested & Keywords

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