In assessing a patient before administration of a cardiac glycoside, the nurse knows that which lab result can increase the toxicity of the drug?

Correct Answer: A

Rationale: Low potassium levels, known as hypokalemia, can increase the toxicity of cardiac glycosides such as digoxin. These drugs work by inhibiting the sodium-potassium pump in cardiac cells, leading to increased intracellular sodium levels. When potassium levels are low, it can worsen this effect and lead to increased risk of cardiac dysrhythmias and toxicity from the drug. Potassium levels should be carefully monitored in patients taking cardiac glycosides to prevent complications. A potassium level of 2.8 mEq/L is considered significantly low and would pose an increased risk of toxicity with cardiac glycoside use.

Correct Answer: B

Rationale: Digitalis has a negative chronotropic effect, meaning it slows down the heart rate. This can be evident in a patient by observing a decrease in their heart rate. Chronotropy refers to the heart rate or rhythm of the heart. Digitalis works by inhibiting the sodium-potassium pump in the heart muscle cells, leading to an increase in intracellular calcium levels. This results in a decreased heart rate and improved contractility of the heart muscle. Therefore, a decreased heart rate is the expected effect when a patient is receiving intravenous digitalis.

Correct Answer: D

Rationale: Metformin is a medication commonly used to treat type 2 diabetes by helping to control high blood sugar levels. It works by decreasing the amount of sugar produced by the liver and increasing the body's response to insulin. By aiding in controlling blood glucose levels, metformin helps prevent complications of diabetes such as kidney damage, blindness, nerve problems, and loss of limbs. It does not lower blood pressure, diminish seizure activity, increase heart rate, or decrease gastrointestinal secretions.

Correct Answer: A

Rationale: Insulin glargine is typically administered subcutaneously. Subcutaneous injection allows for slow and continuous absorption of the medication, providing a sustained release of insulin to help regulate blood sugar levels. This route of administration is commonly used for long-acting insulins like insulin glargine to provide basal insulin coverage throughout the day. Sublingual, oral, IV, and other routes are not appropriate for administering insulin glargine.

Correct Answer: D

Rationale: Acetaminophen is not an opioid or NSAID. While it is commonly used to relieve pain and reduce fever, acetaminophen works differently from opioids and NSAIDs. Acetaminophen is believed to reduce pain by inhibiting the production of prostaglandins in the brain, whereas opioids work by binding to opioid receptors in the central nervous system, and NSAIDs work by inhibiting the production of prostaglandins in the peripheral tissues.