Digoxin (Lanoxin) is a cardiac glycoside that is among the oldest medications used for heart failure.
What are its two primary actions?

Diuretics are medicines that help the kidneys get rid of excess water and salt, which can ease the symptoms of heart failure, such as breathlessness and swelling.However, diuretics may have some side effects, such as loss of potassium, which can affect the heart and require regular blood tests and dietary changes.Diuretics can also cause other electrolyte abnormalities, such as hyponatremia, hypomagnesemia, hypocalcemia, and metabolic alkalosis. Electrolyte disturbances can have serious consequences for the heart function and rhythm, as well as other organs.

Choice A is wrong because fluid retention is the opposite of what diuretics do.

Diuretics reduce fluid retention by increasing urine output and decreasing blood volume.

Choice B is wrong because hypotension is not a direct effect of diuretics on the heart, but rather a consequence of reduced blood volume and vasodilation.

Hypotension can occur with diuretic use, especially if the dose is too high or the patient is dehydrated, but it is not a specific condition caused by diuretics.

Choice C is wrong because hyperglycemia is not related to diuretics or heart failure.

Hyperglycemia is a condition of high blood sugar, which can be caused by diabetes or other factors.

Diuretics do not affect blood sugar levels directly, although some diuretics may interact with diabetes medications and affect their efficacy.

Hypokalemia is a condition of low potassium levels in the blood, which can be caused by diuretics such as furosemide (Lasix) that increase the excretion of potassium in the urine. Potassium is an important electrolyte that helps regulate the function of nerves and muscles, including the heart.Low potassium levels can cause symptoms such as confusion, tremors, muscle cramps, and nausea, which are consistent with the patient’s presentation.

Choice B, renal failure, is wrong because furosemide is used to treat fluid retention and edema caused by kidney disease, not to cause it.Renal failure would also cause symptoms such as decreased urine output, swelling, fatigue, and shortness of breath, which are not mentioned in the question.

Choice C, hyperkalemia, is wrong because hyperkalemia is a condition of high potassium levels in the blood, which can be caused by kidney disease or certain medications that decrease the excretion of potassium in the urine.Hyperkalemia can cause symptoms such as weakness, irregular heartbeat, paralysis, and chest pain, which are different from the patient’s symptoms.

Choice D, heart failure, is wrong because furosemide is also used to treat fluid retention and edema caused by heart failure, not to cause it.Heart failure would also cause symptoms such as shortness of breath, coughing, fatigue, and rapid weight gain, which are not mentioned in the question.

Normal ranges for potassium levels in the blood are 3.5 to 5.0 milliequivalents per liter (mEq/L) for adults and 3.4 to 4.7 mEq/L for children.

A level below 3.5 mEq/L is considered hypokalemic and a level above 5.0 mEq/L is considered hyperkalemic.