Which class of antihypertensive drugs works by blocking calcium entry into vascular smooth muscle?
Thiazide diuretics.
ACE inhibitors.
Calcium channel blockers.
Beta-blockers.
The Correct Answer is C
Choice A rationale
Thiazide diuretics, such as hydrochlorothiazide, lower blood pressure by inhibiting sodium and chloride reabsorption in the distal convoluted tubule of the kidneys. This increases the excretion of water and salt, reducing blood volume and thereby lowering blood pressure.
Choice B rationale
ACE inhibitors, like lisinopril, lower blood pressure by blocking the conversion of angiotensin I to angiotensin II. Angiotensin II is a potent vasoconstrictor, so inhibiting its formation leads to vasodilation and reduced blood pressure, also reducing aldosterone secretion.
Choice C rationale
Calcium channel blockers (CCBs) inhibit the influx of calcium ions into vascular smooth muscle and cardiac cells. This leads to the relaxation of the muscle walls, causing vasodilation and a decrease in peripheral vascular resistance, which in turn lowers blood pressure.
Choice D rationale
Beta-blockers, such as metoprolol, lower blood pressure by blocking the effects of epinephrine and norepinephrine. This leads to a decrease in heart rate, myocardial contractility, and cardiac output, thereby reducing blood pressure. They do not directly block calcium entry into muscle cells.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is D
Explanation
Choice A rationale
Taking the medication before bed is incorrect. Thyroid replacement hormones, such as levothyroxine, can increase metabolism and may cause symptoms of insomnia or restlessness if taken too close to bedtime. Therefore, patients are advised to take the medication in the morning to align with the body's natural circadian rhythm and to minimize sleep disturbances.
Choice B rationale
The full therapeutic effects of thyroid replacement medication are not seen after one week. It typically takes several weeks, often four to six, for the medication to reach a steady-state level in the blood and for the patient to experience the full benefits. The dosage may also be adjusted based on subsequent blood tests and symptom assessment.
Choice C rationale
Stopping the drug because of insomnia is incorrect. Insomnia can be a symptom of hyperthyroidism (too much medication) or other factors. The patient should not abruptly stop the medication but should consult their healthcare provider. The provider can then assess the patient's symptoms, check thyroid hormone levels, and adjust the dosage if necessary, rather than ceasing treatment entirely.
Choice D rationale
Taking the medication in the morning on an empty stomach is correct. Levothyroxine absorption is significantly reduced when taken with food, especially those containing calcium, iron, or dietary fiber. Taking it in the morning, at least 30-60 minutes before breakfast, ensures consistent and optimal absorption, which is critical for maintaining stable thyroid hormone levels.
Correct Answer is A
Explanation
Choice A rationale
Chest pain and palpitations in a patient taking levothyroxine can be signs of thyroid hormone overdose or hyperthyroidism, which can induce cardiac side effects. The cardiovascular system is highly sensitive to thyroid hormones. These symptoms could be indicative of myocardial ischemia, tachycardia, or dysrhythmias, which are serious and require immediate medical evaluation. The nurse's priority is to notify the healthcare provider immediately for dose adjustment or further cardiac workup.
Choice B rationale
Advising the patient to rest and monitor symptoms is an insufficient and potentially dangerous action. While rest may temporarily alleviate some symptoms, it does not address the underlying cause, which could be an overdose of the medication. The nurse should not delay notifying the healthcare provider, as the cardiac symptoms could escalate and lead to a more serious event, such as a myocardial infarction.
Choice C rationale
Antacids containing calcium or aluminum can interfere with the absorption of levothyroxine, but they are not a treatment for chest pain or palpitations related to the medication. Administering an antacid would be inappropriate and would not address the patient's serious cardiac symptoms. The nurse's focus should be on addressing the potential cardiac side effects of the medication and reporting them to the healthcare provider.
Choice D rationale
Increasing the dose of levothyroxine would worsen the patient's symptoms. The chest pain and palpitations suggest that the patient may be receiving too high a dose of the thyroid hormone, leading to symptoms of hyperthyroidism. Increasing the dose would further elevate the circulating thyroid hormone levels, exacerbating the cardiac side effects and increasing the risk of a serious cardiac event.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.