A client is prescribed a thiazide diuretic for the management of hypertension.
The nurse plans to assess the client for allergy to?

This is because low potassium levels (hypokalemia) increase the sensitivity of the heart to digoxin and can lead to toxicity even with normal serum digoxin levels. Digoxin inhibits the sodium-potassium pump on the cardiac cells, which causes potassium to accumulate outside the cells.Low potassium levels in the blood create a larger gradient for potassium to move out of the cells, which enhances the effect of digoxin and can cause arrhythmias.

Choice B is wrong because calcium 9.2 mg/dL is within the normal range (8.5 to 10.2 mg/dL) and does not increase the risk of digoxin toxicity.However, high calcium levels (hypercalcemia) can potentiate the effects of digoxin and cause toxicity.

Choice C is wrong because sodium 140 mEq/L is within the normal range (135 to 145 mEq/L) and does not increase the risk of digoxin toxicity.However, high sodium levels (hypernatremia) can reduce the binding of digoxin to the sodium-potassium pump and decrease its efficacy.

Choice D is wrong because magnesium 2.2 mg/dL is within the normal range (1.7 to 2.4 mg/dL) and does not increase the risk of digoxin toxicity.However, low magnesium levels (hypomagnesemia) can increase the sensitivity of the heart to digoxin and cause toxicity.

PT stands for prothrombin time, which is a measure of how long it takes the blood to clot.

INR stands for international normalized ratio, which is a way of standardizing the PT results across different laboratories.

Warfarin is a blood thinner that works by inhibiting the production of vitamin K-dependent clotting factors in the liver.

Therefore, warfarin prolongs the PT and increases the INR.The PT/INR test is used to monitor the effectiveness of warfarin therapy and adjust the dose accordingly.

Choice A is wrong because PTT stands for partial thromboplastin time, which is another measure of blood clotting time, but it reflects the activity of different clotting factors than PT.PTT is used to monitor heparin therapy, not warfarin therapy.

Choice C is wrong because aPTT stands for activated partial thromboplastin time, which is a variation of PTT that uses an activator to speed up the clotting time.Like PTT, aPTT is used to monitor heparin therapy, not warfarin therapy.

Choice D is wrong because ACT stands for activated clotting time, which is a measure of the whole blood clotting time.ACT is used to monitor high-dose heparin therapy during certain procedures, such as cardiac bypass surgery or angioplasty.

The normal ranges for these tests may vary depending on the laboratory and the method used, but generally, they are:

• PT: 10 to 13 seconds

• INR: 0.8 to 1.2 (without warfarin) or 2.0 to 3.0 (with warfarin)

• PTT: 25 to 35 seconds

• aPTT: 30 to 40 seconds

• ACT: 70 to 120 seconds