A nurse is evaluating a client who has heart failure and is receiving warfarin. Which of the following statements by the client indicates a need for further teaching?

This is because metoprolol is a beta blocker, which can block the beta-2 receptors in the lungs and cause constriction of the airways.This can lead to breathing problems such as shortness of breath, cough, and wheezing. Bronchospasm is more likely to occur in people who have asthma or chronic obstructive pulmonary disease (COPD).

Choice A is wrong because tachycardia, or fast heart rate, is not an adverse effect of metoprolol. In fact, metoprolol can lower the heart rate by blocking the beta-1 receptors in the heart.A normal resting heart rate for adults ranges from 60 to 100 beats per minute (bpm).Metoprolol can cause bradycardia, or slow heart rate, which can be a serious side effect if it is too low.

Choice B is wrong because hyperglycemia, or high blood sugar, is not an adverse effect of metoprolol. Metoprolol does not affect the insulin secretion or glucose metabolism in the body.A normal blood sugar level for adults without diabetes is less than 140 mg/dL (7.8 mmol/L) two hours after eating. Metoprolol can cause hypoglycemia, or low blood sugar, in people who have diabetes and take insulin or other glucose-lowering medications.This is because metoprolol can mask the symptoms of hypoglycemia, such as palpitations and tremors.

Choice D is wrong because hyperkalemia, or high potassium, is not an adverse effect of metoprolol. Metoprolol does not affect the potassium balance in the body.

A normal blood potassium level for adults is 3.6 to 5.2 millimoles per liter (mmol/L)

The nurse should monitor the serum potassium level to determine the therapeutic effectiveness of carvedilol (Coreg), which is a beta-blocker that can lower the heart rate and blood pressure. Carvedilol can also cause hyperkalemia, which is a high level of potassium in the blood that can lead to cardiac arrhythmias and muscle weakness.Therefore, the nurse should monitor the serum potassium level and report any values above 5.0 mEq/L to the provider.

Choice B) Serum sodium level is wrong because carvedilol does not affect the sodium level significantly.Sodium level is more relevant for diuretics, which can cause hyponatremia (low sodium) or hypernatremia (high sodium) depending on the type and dose of the medication.

Choice C) Serum magnesium level is wrong because carvedilol does not affect the magnesium level significantly.

Magnesium level is more relevant for digoxin, which is another medication used for heart failure that can cause hypomagnesemia (low magnesium) or hypermagnesemia (high magnesium).Hypomagnesemia can increase the risk of digoxin toxicity, while hypermagnesemia can decrease the effectiveness of digoxin.

Choice D) Serum calcium level is wrong because carvedilol does not affect the calcium level significantly.

Calcium level is more relevant for calcium channel blockers, which are another class of medications used for heart failure that can lower the heart rate and blood pressure by blocking the entry of calcium into the cardiac and vascular smooth muscle cells.

Calcium channel blockers can cause hypocalcemia (low calcium) or hypercalcemia (high calcium), which can affect the cardiac contractility and conduction.

The normal ranges for serum electrolytes are:

• Potassium: 3.5 to 5.0 mEq/L

• Sodium: 135 to 145 mEq/L

• Magnesium: 1.5 to 2.5 mEq/L

• Calcium: 8.5 to 10.5 mg/dL