A patient on levothyroxine reports chest pain and palpitations.
What is the nurse's priority action?

Choice A rationale

Giving the insulin is not safe because there is a possibility the patient has already received it, even though the record is not signed. Administering a second dose of insulin could lead to hypoglycemia, a life-threatening condition where the blood glucose level drops dangerously low, causing symptoms like confusion, seizures, and unconsciousness.

Choice B rationale

Holding the insulin is the initial safe action, but simply holding it doesn't resolve the issue and leaves the patient's care plan incomplete. The primary concern is the potential for a double dose and the lack of proper documentation. The problem requires a more formal and structured response than simply holding the medication and moving on.

Choice C rationale

Contacting the night nurse is an option, but it is not the most immediate or appropriate action. The night nurse may be asleep or unreachable. The nurse on duty is responsible for the patient's safety and should follow proper chain of command and reporting protocols to resolve the issue promptly and ensure patient safety.

Choice D rationale

This situation involves a medication discrepancy, a potential medication error, and a significant safety risk to the patient. Reporting it to the nursing supervisor is the correct and necessary action. The supervisor can initiate a formal investigation, ensure the patient is safe, and address the documentation issue to prevent future errors.

Choice A rationale

Antithyroid drugs are used to treat hyperthyroidism, a condition characterized by excessive thyroid hormone production. Their primary mechanism is to decrease, not increase, the synthesis of thyroid hormones to bring the body's metabolic rate back to a normal range.

Choice B rationale

The primary action of antithyroid medications, such as methimazole and propylthiouracil, is to inhibit the synthesis of thyroid hormones within the thyroid gland. They achieve this by blocking key enzymatic steps involved in the production of triiodothyronine ($T_3$) and thyroxine ($T_4$).

Choice C rationale

Antithyroid drugs do not directly stimulate the release of thyroid-stimulating hormone (TSH). TSH is produced by the pituitary gland, and its release is primarily regulated by the hypothalamus's secretion of thyrotropin-releasing hormone (TRH) and a negative feedback loop from circulating thyroid hormones.

Choice D rationale

While some antithyroid treatments, like radioactive iodine, do destroy thyroid tissue, this is not the primary action of most antithyroid drugs such as methimazole and propylthiouracil. These drugs work by inhibiting hormone production, leaving the thyroid tissue itself intact.