A nurse is educating a client who has a new prescription for metformin about how to take this medication. Which of the following instructions should the nurse include in the teaching?

B) Correct. The nurse should monitor serum potassium closely while the client is taking furosemide, as this medication is a loop diuretic that can cause hypokalemia or low potassium levels, which can lead to cardiac arrhythmias or muscle weakness.

A) Incorrect. Although serum creatinine is an indicator of kidney function, it is not directly affected by furosemide, as this medication does not cause nephrotoxicity or damage to the kidneys.

C) Incorrect. Although serum calcium is an electrolyte that can affect neuromuscular function, it is not directly affected by furosemide, as this medication does not cause hypocalcemia or low calcium levels.

D) Incorrect. Although serum albumin is a protein that can affect fluid balance, it is not directly affected by furosemide, as this medication does not cause hypoalbuminemia or low albumin levels.

A) Correct. The nurse should instruct the client to take metformin with meals to reduce gastrointestinal upset, such as nausea, vomiting, diarrhea, or abdominal pain, which are common adverse effects of this medication.

B) Incorrect. The nurse should not instruct the client to take metformin at bedtime, as this may increase the risk of lactic acidosis, a rare but serious complication of this medication that can cause muscle pain, weakness, fatigue, or hyperventilation.

C) Incorrect. The nurse should not instruct the client to take metformin with grapefruit juice, as this may interfere with its metabolism and increase its blood levels, which can lead to hypoglycemia or low blood sugar levels.

D) Incorrect. The nurse should not instruct the client to take metformin with an antacid, as this may decrease its absorption and effectiveness in lowering blood sugar levels.