What is the therapeutic use of levothyroxine?

Correct Answer: C

Rationale: Levothyroxine is a synthetic form of the thyroid hormone thyroxine and is commonly used for the treatment of hypothyroidism. Hypothyroidism is a condition where the thyroid gland does not produce enough thyroid hormone to meet the body's needs, leading to various symptoms such as fatigue, weight gain, cold intolerance, and depression. By providing exogenous levothyroxine, the medication helps restore normal thyroid hormone levels in the body, thereby alleviating the symptoms of hypothyroidism and restoring normal hormonal balance. It is important to monitor thyroid hormone levels regularly when on levothyroxine therapy to ensure optimal dosing and maintenance of normal thyroid function.

Correct Answer: C

Rationale: Epinephrine primarily acts on beta1 adrenergic receptors in the alveolar mucosa during root end surgery. This results in vasoconstriction, which reduces bleeding in the surgical field by constricting blood vessels. With decreased bleeding, the surgical site becomes clearer, allowing for better visualization and manipulation during the procedure. Additionally, epinephrine may also prolong the duration of anesthesia by reducing systemic uptake of the local anesthetic solution, thus enhancing its effect locally.

Correct Answer: A

Rationale: Adverse effects of amiodarone include QT prolongation and gray coloring of the skin on the face, arms, and neck.

Correct Answer: C

Rationale: Levothyroxine is a synthetic form of the thyroid hormone thyroxine (T4). It is primarily used for the treatment of hypothyroidism, a condition in which the thyroid gland does not produce enough thyroid hormone. By providing exogenous levothyroxine, the medication helps to restore the normal hormonal balance in the body. This can alleviate symptoms such as fatigue, weight gain, cold intolerance, and other issues related to an underactive thyroid gland. Levothyroxine is not used for the suppression of seizure activity, decreased frequency of migraines, or treatment of ulcers.

Correct Answer: A

Rationale: Spironolactone is a potassium-sparing diuretic, which belongs to the aldosterone receptor antagonists. It works by inhibiting aldosterone activity in the distal convoluted tubule and collecting ducts of the kidney. Aldosterone promotes sodium reabsorption in exchange for potassium and hydrogen ions. By blocking aldosterone, Spironolactone allows for increased excretion of sodium while retaining potassium and hydrogen ions, making it a suitable choice for patients who need to maintain potassium levels or are at risk for hypokalemia.