The side effects of sublingual nitro-glycerin are?

KPSC Staff Nurse - 2017

Pharmacology

Medium

Appeared in: KPSC Staff Nurse - 2017

Explanation

Nitroglycerin is a potent vasodilator, causing relaxation of blood vessels throughout the body.
This vasodilation leads to a decrease in blood pressure (hypotension).
The body compensates for the drop in blood pressure by increasing the heart rate, a phenomenon known as reflex tachycardia.
Dilation of blood vessels in the head (meningeal arteries) is the cause of the common side effect of a throbbing headache.

Option A: This option incorrectly includes hypertension. Nitroglycerin is a vasodilator and causes hypotension (low blood pressure), not hypertension (high blood pressure).
Option C: This option incorrectly includes bradycardia (slow heart rate). The typical response to the drop in blood pressure caused by nitroglycerin is a compensatory reflex tachycardia (fast heart rate).
Option D: This option incorrectly includes cyanosis. Cyanosis is not a typical side effect of therapeutic doses of nitroglycerin. It is a sign of severe hypoxia or methemoglobinemia, which is a rare complication of nitrate overdose.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pharmacology: Side Effects of Nitroglycerin as background academic context rather than a clinical decision trigger.
Nurses must educate patients that headache is a very common and expected side effect, which often indicates the medication is working. This can improve adherence.
A critical nursing responsibility is to assess blood pressure before and after administration. Withholding the drug if the patient is hypotensive (e.g., SBP less than 90 mmHg) prevents dangerous drops in blood pressure.
Patient safety is paramount. Instructing the patient to sit or lie down before taking sublingual nitroglycerin minimizes the risk of falls and injury from orthostatic hypotension and dizziness.

How to Approach the Question

First, identify the core subject of the question: the side effects of sublingual nitroglycerin.
Recall the drug class and primary mechanism of action for nitroglycerin. It is a nitrate, which acts as a potent vasodilator.
Think through the physiological consequences of widespread vasodilation. Dilation of veins and arteries will cause blood pressure to drop (hypotension).
Consider the body's natural compensatory mechanisms. A rapid drop in blood pressure will trigger the baroreceptor reflex, leading to an increase in heart rate (tachycardia).
Consider the effect of vasodilation on other parts of the body, specifically the head. Dilation of cerebral vessels leads to headache.
Combine these three primary effects: hypotension, tachycardia, and headache. Scan the options to find the one that matches this triad.

Concept Tested & Keywords

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