Which laboratory test measures the effectiveness of warfarin?
PTT.
PT/INR.
aPTT.
ACT.
The Correct Answer is B
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
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is C
Explanation
Urecholine is the brand name of bethanechol, a drug that belongs to the class of cholinergics, genitourinary.
Choice A is wrong because adrenergic drugs are those that activate the sympathetic nervous system, which is responsible for the fight-or-flight response.Adrenergic drugs can cause relaxation of the bladder and urinary retention, not contraction and emptying.
Choice B is wrong because anticholinergic drugs are those that block the action of acetylcholine, a neurotransmitter that mediates the parasympathetic nervous system, which is responsible for the rest-and-digest response.Anticholinergic drugs can also cause relaxation of the bladder and urinary retention, not contraction and emptying.
Choice D is wrong because adrenergic blockers are those that inhibit the action of adrenergic receptors, which are activated by adrenergic drugs or by the natural neurotransmitters norepinephrine and epinephrine.Adrenergic blockers can have various effects on the bladder depending on the type and location of the receptors they block, but they are not used to treat urinary retention.
Correct Answer is ["B"]
Explanation
This is a mnemonic to remember the common suffix of drugs that block the beta receptors in the heart and blood vessels, which can lower blood pressure, heart rate, and reduce chest pain. For example, metoprolol, atenolol, and propranolol are beta blockers.
Choice A is wrong because calcium channel blockers do not end in DIPINE.
Calcium channel blockers are drugs that block the entry of calcium into the cells of the heart and blood vessels, which can relax the blood vessels and lower blood pressure.
Some calcium channel blockers end in DIPINE, such as amlodipine and nifedipine, but not all of them.
For example, verapamil and diltiazem are also calcium channel blockers.
Choice C is wrong because ACE inhibitors do not end in ZoSIN.
ACE inhibitors are drugs that inhibit the enzyme angiotensin-converting enzyme (ACE), which can lower blood pressure and prevent heart failure.
ACE inhibitors usually end in PRIL, such as lisinopril, enalapril, and captopril.
Choice D is wrong because angiotensin II receptor blockers do not end in STATIN.
Angiotensin II receptor blockers are drugs that block the action of angiotensin II, a hormone that constricts blood vessels and raises blood pressure.
Angiotensin II receptor blockers usually end in SARTAN, such as losartan, valsartan, and irbesartan.
The normal range for blood pressure is less than 120/80 mmHg.
The normal range for heart rate is 60 to 100 beats per minute.
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