Which lab value should the nurse monitor in a patient taking antithyroid drugs?

Choice A rationale

Metoprolol is a beta-blocker that reduces myocardial oxygen demand by decreasing heart rate, contractility, and blood pressure. While it is effective for long-term management and prevention of angina, it is not the preferred choice for immediate relief of an acute anginal attack due to its slower onset of action. Its primary role is prophylaxis.

Choice B rationale

Nitroglycerin is a potent vasodilator that works by relaxing vascular smooth muscle, primarily affecting veins, which reduces venous return (preload) and myocardial oxygen demand. It also dilates coronary arteries, increasing blood flow and oxygen supply to the heart muscle. Its rapid onset makes it the drug of choice for acute angina.

Choice C rationale

Amlodipine is a calcium channel blocker that works by inhibiting the influx of calcium into vascular smooth muscle and myocardial cells, causing vasodilation and reduced peripheral resistance. Although it is used for the long-term management of chronic stable angina, its onset of action is not rapid enough for immediate relief during an acute attack.

Choice D rationale

Aspirin is an antiplatelet agent that works by irreversibly inhibiting cyclooxygenase (COX) enzyme, preventing the formation of thromboxane A2. This reduces platelet aggregation and clot formation, which is crucial in preventing myocardial infarction in the setting of unstable angina, but it does not provide immediate relief from chest pain.

Choice A rationale

While blood pressure is an important vital sign, it is not the primary assessment before administering a hypnotic medication unless the medication has a known and significant effect on blood pressure, such as causing hypotension. Assessing for current or recent blood pressure is not the most crucial factor compared to the patient's history of substance abuse, given the nature of these medications.

Choice B rationale

Recent blood glucose levels are not a primary concern for most hypnotic medications unless the patient has a history of diabetes or the medication is known to affect glucose metabolism. This assessment would be more relevant for medications like corticosteroids or certain antipsychotics, but it is not a routine or critical pre-administration assessment for hypnotics.

Choice C rationale

A patient's dietary intake is generally not the most critical assessment before administering a hypnotic medication, although some foods or beverages, like caffeine, can interfere with sleep. The primary concerns are the patient's history of substance use, other medications, and potential contraindications related to central nervous system depression.

Choice D rationale

Hypnotic medications, which are central nervous system depressants, have a high potential for abuse and dependence. A history of substance abuse, including alcohol or other sedatives, significantly increases the risk of addiction, tolerance, and withdrawal symptoms. Therefore, assessing this history is a crucial step to ensure patient safety and prevent misuse or overdose.