Order: diphenhydramine 25 mg PO q6h, PRN

Available: diphenhydramine 12.5 mg/5 mL.

How many mL would the nurse give?

A) Neutropenia
Neutropenia refers to an abnormally low level of neutrophils, a type of white blood cell. While certain medications, such as chemotherapy agents and some antipsychotic drugs, can cause neutropenia, atenolol (a beta-blocker) is not typically associated with this side effect. Atenolol primarily affects the cardiovascular system by reducing heart rate and blood pressure, and it is not known to cause significant changes in white blood cell counts.

B) Bradycardia
Bradycardia, or a slower-than-normal heart rate, is a well-known and common adverse effect of beta-blockers, including atenolol. Beta-blockers work by blocking beta-adrenergic receptors, which decreases the heart rate and the force of contraction, as well as lowering blood pressure. In some individuals, this can lead to excessively low heart rates, which could be dangerous if the heart rate drops too much. Bradycardia can lead to symptoms such as dizziness, fainting, or fatigue, and may require dose adjustments or discontinuation of the medication

C) Anemia
Anemia, which is a condition characterized by a low red blood cell count or low hemoglobin levels, is generally not a common adverse effect of atenolol. While certain medications like some chemotherapeutic agents, NSAIDs, or antibiotics may cause anemia due to their effects on the bone marrow or by causing gastrointestinal bleeding, atenolol is not typically linked to this side effect.

D) Hypokalemia
Hypokalemia (low potassium levels) is typically associated with the use of diuretics or other medications that cause the kidneys to excrete more potassium, such as some classes of antibiotics and corticosteroids. However, atenolol, being a beta-blocker, does not directly affect potassium levels.

A) Bradycardia
Bradycardia (a slow heart rate) is not the most common response to nitroglycerin (NTG). While NTG can affect heart rate in some individuals, its primary action is related to blood vessels, and it typically leads to vasodilation, which more commonly results in reflex tachycardia (an increased heart rate), rather than bradycardia.

B) Tachycardia
Tachycardia (an increased heart rate) can occur as a compensatory mechanism when nitroglycerin causes vasodilation and a decrease in blood pressure. However, this is more of a secondary effect. The primary action of nitroglycerin is to lower blood pressure (by dilating blood vessels), and in response to the lowered blood pressure, the body may try to compensate by increasing the heart rate.

C) Hypotension
The most common and primary response to nitroglycerin (NTG) administration is hypotension. Nitroglycerin works by relaxing smooth muscle in blood vessels, leading to vasodilation (widening of blood vessels). This reduces the amount of work the heart has to do and lowers the overall blood pressure. Hypotension is expected as part of the therapeutic effect of NTG, especially with a larger dose or rapid administration (e.g., sublingual NTG).

D) Dry mouth
While many medications can cause dry mouth (especially anticholinergic drugs), nitroglycerin is not typically associated with this issue. Its primary action is vasodilation, and while it can cause other symptoms like headaches, dizziness, and hypotension, dry mouth is not considered a common or significant effect.