Which of the following drugs is to be infused fast?

NHM UP Staff Nurse - 2016

Pharmacology

Easy

Appeared in: NHM UP Staff Nurse - 2016

Explanation

Mannitol is an osmotic diuretic used to treat conditions like cerebral edema and increased intracranial pressure (ICP).
It is administered as a rapid intravenous infusion or bolus, typically over 15 to 30 minutes.
This rapid administration is necessary to create a high concentration of the drug in the blood quickly, establishing an osmotic gradient that pulls fluid from brain tissue into the bloodstream, thus reducing pressure.

Option A: Rapid infusion of Aminophylline, a bronchodilator, can cause severe and life-threatening adverse effects, including severe hypotension, cardiac arrhythmias, and seizures.
Option C: Dopamine is a potent vasoactive drug that must be administered as a continuous, titrated infusion using an infusion pump. A rapid bolus can cause a dangerous hypertensive crisis and severe tachyarrhythmias.
Option D: Potassium chloride must be diluted and infused very slowly. Rapid infusion or IV push is absolutely contraindicated and can be lethal, causing hyperkalemia that leads to immediate cardiac arrest.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain IV drug administration rates and safety as background academic context rather than a clinical decision trigger.
Knowing the correct infusion rate for IV medications is a critical nursing responsibility for patient safety. Rapid infusion of drugs intended for slow administration can have fatal consequences.
When administering Mannitol, the nurse must use an in-line filter to catch any crystals that may have formed in the solution. The solution should be inspected for crystals before administration and warmed to dissolve if necessary.
What if a patient receiving Mannitol develops crackles in the lungs and shortness of breath? This suggests pulmonary edema, a serious side effect. The nurse must stop the infusion immediately and notify the physician, as fluid has shifted into the vascular space too quickly for the heart to handle.

How to Approach the Question

First, identify the core of the question, which is to find the drug that is administered 'fast' among the given options.
Next, review each option based on your knowledge of pharmacology and IV administration safety.
Consider Potassium Chloride. This is a high-alert medication known to be fatal if given rapidly. Eliminate this option.
Consider Dopamine. This is a potent vasopressor that requires careful titration via an infusion pump to manage its effects on blood pressure and heart rate. It is never given as a fast bolus. Eliminate this option.
Consider Aminophylline. This drug has a narrow therapeutic index, and rapid infusion can lead to severe cardiac and CNS toxicity. It is given slowly. Eliminate this option.
This leaves Mannitol. Recall that as an osmotic diuretic, its mechanism requires rapid administration to create an effective osmotic gradient to pull fluid from tissues. This makes it the correct answer.

Concept Tested & Keywords

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E6 Pharmacology Nursing Lilley 11e Part 1 p. 318-320

E6 Pharmacology Nursing Lilley 11e Part 2 p. 171-173