A nurse is reviewing the health record of a client who asks about using propranolol to treat hypertension.
The nurse should recognize which of the following conditions is a contraindication for taking propranolol?

This is because potassium sparing diuretics do not lower potassium levels in the blood, unlike other types of diuretics.Potassium is an essential electrolyte that serves nerve and muscular functions and is regulated by the kidneys.Low potassium levels can cause irregular heartbeats and other problems. Therefore, patients taking potassium sparing diuretics should avoid food sources that are high in potassium, such as bananas, avocados, spinach, and potatoes.

Choice A is wrong because thiazide diuretics, such as hydrochlorothiazide, can cause low potassium levels in the blood.

Patients taking thiazide diuretics may need to take potassium supplements or eat more potassium-rich foods to prevent hypokalemia.

Choice B is wrong because osmotic diuretics, such as mannitol, do not affect potassium levels in the blood.

They work by increasing the amount of water in the urine, but do not alter the electrolyte balance.

Osmotic diuretics are mainly used to treat cerebral edema and glaucoma.

Choice D is wrong because loop diuretics, such as furosemide, can also cause low potassium levels in the blood.

They work by inhibiting the reabsorption of sodium and water in the loop of Henle, a part of the kidney.

Loop diuretics are used to treat edema and heart failure.

Normal ranges for potassium in the blood are 3.5 to 5.0 millimoles per liter (mmol/L).

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.