Which drugs act on the sympathetic nervous system, which regulates blood pressure by controlling heart rate, cardiac output, vascular tone, and renin release?

Digoxin (Lanoxin) is a cardiac glycoside that is used to improve the contractility of the heart and slow down the heart rate in patients with chronic heart failure. However, digoxin has a narrow therapeutic range and can cause toxicity if the dose is too high or if the patient has low potassium levels. A normal serum digoxin level is 0.5 to 2 ng/mL and a normal serum potassium level is 3.5 to 5 mEq/L. A low heart rate (less than 60 beats/min) is a sign of digoxin toxicity and the nurse should withhold the medication and report it to the provider. The nurse should also check the patient’s serum digoxin and potassium levels to determine if they are within normal limits.

Choice A is wrong because administering the medication as ordered could worsen the patient’s condition and increase the risk of digoxin toxicity.

Choice C is wrong because checking the patient’s serum digoxin level is not enough to prevent digoxin toxicity. The nurse should also check the patient’s serum potassium level and heart rate before giving digoxin.

Choice D is wrong because giving an additional dose of digoxin could cause a fatal overdose and lead to cardiac arrest. The nurse should never give more than the prescribed dose of digoxin without consulting the provider.

The correct answer is choice B. “I can walk farther without getting tired.” This statement indicates a therapeutic effect of metoprolol, which is a beta-blocker that reduces the heart rate, blood pressure, and the workload of the heart.This helps to improve the blood flow and oxygen delivery to the heart and other organs, and reduces the symptoms of heart failure such as fatigue, dyspnea, and edema.

Choice A is wrong because “I have less swelling in my ankles.” This statement indicates a possible effect of a diuretic, which is a medication that reduces fluid retention and edema by increasing urine output.Metoprolol does not have a direct diuretic effect, although it may indirectly reduce fluid accumulation by improving cardiac function.

Choice C is wrong because “I don’t have chest pain anymore.” This statement indicates a possible effect of a nitrate, which is a medication that dilates the blood vessels and reduces the oxygen demand of the heart.Metoprolol may also help to prevent or treat angina by lowering the heart rate and blood pressure, but it is not the primary medication for chest pain relief.

Choice D is wrong because “I can breathe better at night.” This statement indicates a possible effect of an oxygen therapy, which is a treatment that delivers supplemental oxygen to the lungs and improves gas exchange.Metoprolol may also help to reduce dyspnea by improving cardiac function and reducing pulmonary congestion, but it is not the primary treatment for respiratory distress.