A patient who has been anticoagulated with warfarin (Coumadin) has been admitted for gastrointestinal bleeding. The history and physical examination indicates that the patient may have taken too much warfarin. The nurse anticipates that the patient will receive which antidote?

Correct Answer: B

Rationale: The correct answer is B: vitamin K. Vitamin K is the antidote for warfarin overdose as it helps in replenishing the depleted clotting factors inhibited by warfarin. Warfarin inhibits the synthesis of vitamin K-dependent clotting factors in the liver, leading to increased bleeding risk. Vitamin K administration helps reverse the anticoagulant effects by promoting the production of these clotting factors. A: Vitamin E is not the antidote for warfarin overdose. Vitamin E does not have any direct role in reversing the anticoagulant effects of warfarin. C: Protamine sulfate is the antidote for heparin, not warfarin. It works by neutralizing heparin's anticoagulant effects. D: Potassium chloride is not the antidote for warfarin overdose. It is used to correct potassium imbalances in the body and has no role in reversing anticoagulant effects of warfarin.

Correct Answer: D

Rationale: Biotransformation aims to make drugs more polar and water-soluble to facilitate their elimination. This process usually involves adding functional groups to increase polarity, making drugs less lipid-soluble. Therefore, the correct answer is D. Choice A is incorrect because ionization is not the primary focus of biotransformation. Choice B is incorrect as increased pharmacological activity is not a goal of biotransformation. Choice C is incorrect because increasing lipid solubility would hinder drug elimination, contrary to the purpose of biotransformation.

Correct Answer: D

Rationale: Step-by-step rationale: 1. Competitive antagonism occurs when two substances compete for the same receptor. 2. In this type, the antagonist binds to the receptor site, preventing the agonist from binding. 3. This results in a decrease in the response produced by the agonist. 4. Summarized, potentiated, and additive antagonisms do not involve direct competition for the receptor site. 5. Summarized means concise or brief, potentiated means increased effect, and additive means combined effect. 6. Therefore, the correct answer is D (Competitive) as it specifically describes the type of antagonism where substances compete for the same receptor site.

Correct Answer: C

Rationale: The correct answer is C: Procaine. Procaine is more likely to cause allergic reactions due to its structural similarity to PABA, a common allergen. It can trigger allergic responses in individuals sensitive to PABA. Lidocaine, Bupivacaine, and Ropivacaine are less likely to cause allergic reactions as they have different chemical structures and mechanisms of action. Allergy to these drugs is rare compared to procaine.

Correct Answer: D

Rationale: The correct answer is D: Ventricle. Muscarinic receptors are predominantly found in the atria, sinoatrial node, and atrioventricular node. Blocking these receptors can lead to decreased heart rate and conduction. The ventricles, however, are more sensitive to beta-adrenergic stimulation rather than muscarinic blockade. This is because beta-adrenergic receptors play a significant role in the contractility of the ventricles. Therefore, the ventricles are not as sensitive to muscarinic receptor blockade compared to the other parts of the heart.