The antidote to warfarin toxicity is what?
Vitamin B12.
Vitamin K.
Calcium gluconate.
Protamine sulfate
The Correct Answer is B
Vitamin K is the antidote for warfarin toxicity because it can reverse the effects of warfarin by restoring the clotting factors. Warfarin is an oral anticoagulant that works by inhibiting vitamin K epoxide reductase, an enzyme that activates vitamin K in the body. Vitamin K is needed for the synthesis of active coagulation factors, such as II, VII, IX and X. By blocking vitamin K, warfarin reduces the blood’s clotting activity and prevents the formation of blood clots.
Choice A is wrong because vitamin B12 is not involved in the coagulation cascade. Vitamin B12 is mainly involved in DNA synthesis, red blood cell production and nerve function.
Choice C is wrong because calcium gluconate is not an antidote for warfarin toxicity. Calcium gluconate is used to treat low blood calcium levels or hypocalcemia. Calcium is also a cofactor for some coagulation factors, but it does not reverse the effects of warfarin.
Choice D is wrong because protamine sulfate is not an antidote for warfarin toxicity.
Protamine sulfate is used to reverse the effects of heparin, another type of anticoagulant that works by inhibiting thrombin and factor Xa.
Protamine sulfate does not affect the vitamin K-dependent coagulation factors that are inhibited by warfarin.
Normal ranges for coagulation tests that are affected by warfarin are:
• Prothrombin time (PT): 11 to 13.5 seconds
• International normalized ratio (INR): 0.8 to 1.2
• Activated partial thromboplastin time (aPTT): 25 to 35 seconds
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is D
Explanation
The correct answer is Choice D: Headache.
Choice A rationale: Nausea is not a common adverse effect of sublingual nitroglycerin. Nausea may occur in some patients, but it is usually mild and transient.Nausea may be related to the vasodilatory effects of nitroglycerin, which can cause hypotension and reflex tachycardia1. Nausea may also be caused by other factors, such as anxiety, stress, or food intolerance.Nausea is not a specific indicator of nitroglycerin toxicity or overdose2.
Choice B rationale: Bradycardia is not a common adverse effect of sublingual nitroglycerin. Bradycardia is a slow heart rate, usually defined as less than 60 beats per minute.Bradycardia may occur in some patients who take nitroglycerin, especially in combination with other drugs that affect the heart rate, such as beta-blockers, calcium channel blockers, or digoxin3. Bradycardia may also be caused by other factors, such as vagal stimulation, hypothyroidism, or electrolyte imbalance.Bradycardia is not a specific indicator of nitroglycerin toxicity or overdose2.
Choice C rationale: Hypertension is not a common adverse effect of sublingual nitroglycerin. Hypertension is a high blood pressure, usually defined as more than 140/90 mmHg.Hypertension may occur in some patients who take nitroglycerin, especially in those who have a history of hypertension, renal impairment, or volume overload4. Hypertension may also be caused by other factors, such as stress, pain, or caffeine intake.Hypertension is not a specific indicator of nitroglycerin toxicity or overdose2.
Choice D rationale: Headache is a common adverse effect of sublingual nitroglycerin.Headache may occur in up to 80% of patients who take nitroglycerin, especially during the first few days of therapy or after an increase in dose5. Headache may be related to the vasodilatory effects of nitroglycerin, which can cause cerebral vasodilation and increased intracranial pressure. Headache may also be caused by other factors, such as dehydration, sinusitis, or migraine. Headache is usually mild to moderate in intensity and can be relieved by analgesics, such as acetaminophen or aspirin.Headache is not a specific indicator of nitroglycerin toxicity or overdose
Correct Answer is C
Explanation
Positive inotropy and negative chronotropy.Digoxin is a cardiac glycoside that increases the force of the heart contractions (positive inotropy) and slows down the heart rate (negative chronotropy).
Choice A is wrong because positive chronotropy means increasing the heart rate, which is the opposite of what digoxin does.
Choice B is wrong because negative inotropy means decreasing the force of the heart contractions, which is also the opposite of what digoxin does.
Choice D is wrong because positive chronotropy means increasing the heart rate, which is not what digoxin does.
Digoxin is used to treat heart failure and atrial fibrillation, a type of irregular heartbeat.It has a narrow therapeutic window, meaning that the dose must be carefully adjusted to avoid toxicity or ineffectiveness.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today