What is a common complication of hydrochlorothiazide treatment that relates to blood pressure?

• A. Decreased venous return
• B. Increased stroke volume
• C. Hypokalemia
• D. Orthostatic hypotension

Answer: (D)

Hydrochlorothiazide is a thiazide diuretic commonly used to manage hypertension. A known complication of its use is orthostatic hypotension, which refers to a significant drop in blood pressure that occurs upon standing up from a sitting or lying position.

The mechanism behind this complication involves the diuretic effect of hydrochlorothiazide, leading to a reduction in blood volume. As blood volume decreases, the body's ability to maintain adequate blood pressure when changing positions is impaired. This can result in dizziness, lightheadedness, or fainting when the individual stands, particularly if they are dehydrated or if their body's compensatory mechanisms are slow to adjust.

While decreased venous return and increased stroke volume are physiological responses that can occur with changes in blood volume and blood pressure, they do not directly correlate as complications of hydrochlorothiazide. Hypokalemia, another potential side effect of thiazide diuretics, does not specifically relate to blood pressure regulation in the context of standing or postural changes. Thus, orthostatic hypotension is the most relevant and recognized complication related to blood pressure that arises from the treatment with hydrochlorothiazide.