A patient arrives at the hospital emergency department via EMS, complaining of being “lightheaded”. The patient has a heart rate of 42 and BP 90/50 mmHg.

What medication should the RN anticipate being prescribed and administered immediately?

Choice A rationale:

Norepinephrine is a potent vasoconstrictor, meaning it narrows blood vessels. It primarily acts on arteries, but it can also constrict veins to a lesser extent.

Its primary actions are to increase systemic vascular resistance and blood pressure.

It is often used in conditions such as shock to raise blood pressure and improve perfusion to vital organs.

It is not a vasodilator and would not be appropriate for a patient requiring dilation of both arteries and veins.

Choice B rationale:

Nitroglycerin is a vasodilator that primarily acts on veins. It relaxes the smooth muscle in the walls of veins, which allows them to dilate and hold more blood.

This reduces the amount of blood returning to the heart, which in turn lowers preload and reduces cardiac workload.

Nitroglycerin is often used to treat angina pectoris, a condition characterized by chest pain due to insufficient blood flow to the heart.

While it can also have some vasodilatory effects on arteries, its primary action is on veins.

Choice C rationale:

Nitroprusside sodium (Nitropress) is a potent vasodilator that acts on both arteries and veins. It directly relaxes smooth muscle in the blood vessel walls, leading to dilation.

It is a very powerful vasodilator and can rapidly lower blood pressure.

It is often used in hypertensive emergencies to quickly reduce blood pressure and improve cardiac function.

It is also used in conditions such as congestive heart failure and acute aortic dissection to reduce afterload and improve cardiac output.

Choice D rationale:

Lidocaine is a local anesthetic agent that is primarily used to block nerve conduction. It does not have any direct vasodilatory effects.

It is sometimes used in the treatment of cardiac arrhythmias, but its mechanism of action in this setting is not related to vasodilation.

Choice A rationale:

Glipizide does not directly enhance glucose transport into the muscles. This action is primarily mediated by insulin, which increases the expression of glucose transporter proteins (GLUT4) on muscle cell membranes, facilitating glucose uptake.

While glipizide can indirectly improve glucose transport into muscles by increasing insulin levels, it's not the primary mechanism of action.

Choice B rationale:

Glipizide does not directly facilitate glucose utilization by body cells. This process also largely depends on insulin, which activates intracellular pathways that promote glucose metabolism and energy production.

Although glipizide can indirectly enhance glucose utilization by increasing insulin availability, it's not the main mechanism responsible for its glucose-lowering effects.

Choice C rationale:

Glipizide does not boost glucose levels. In fact, it has the opposite effect, lowering blood glucose levels by stimulating insulin secretion.

Elevating glucose levels would be counterproductive in diabetes management, as the goal is to maintain blood glucose within a healthy range.

Choice D rationale (correct answer):

Glipizide belongs to a class of medications called sulfonylureas, which act primarily by stimulating insulin secretion from pancreatic beta cells.

Insulin is a hormone that plays a crucial role in regulating blood glucose levels. It promotes glucose uptake by various tissues, including muscles, liver, and adipose tissue, and it inhibits glucose production by the liver.

By triggering insulin release, glipizide effectively lowers blood glucose levels. This helps to prevent the long-term complications of diabetes, such as damage to blood vessels, nerves, and organs.