When converting from IV heparin to oral warfarin (Coumadin) therapy, the prescriber monitors which of the following to determine the next appropriate dose of warfarin?

Correct Answer: D

Rationale: When converting from IV heparin to oral warfarin therapy, the prescriber monitors the Prothrombin Time (PT) and International Normalized Ratio (INR) to determine the next appropriate dose of warfarin. PT measures the time it takes for blood to clot and INR helps standardize PT results. These tests are crucial in evaluating and adjusting the dosage of warfarin to achieve the desired anticoagulant effect while minimizing the risk of bleeding. Monitoring PT/INR levels regularly is essential to ensure that the patient receives the correct dose of warfarin for their specific condition and to prevent complications. Platelet levels, aPTT, and red blood cell count are not typically used to monitor warfarin therapy.

Correct Answer: C

Rationale: The antidote for Warfarin, a common blood thinner medication, is Vitamin K. Warfarin works by inhibiting Vitamin K-dependent coagulation factors, which prevents blood clotting. In case of an overdose or excessive bleeding while taking Warfarin, administering Vitamin K can help counteract the effects of the medication and promote blood clotting.

Correct Answer: C

Rationale: An agonist is a substance that binds to a receptor and activates it, leading to a biological response. Agonists mimic the action of endogenous ligands that normally bind to the receptor, resulting in activation of downstream signaling pathways. This activation can lead to various physiological effects depending on the specific receptor and pathway involved. In contrast, antagonists block or inhibit the actions of agonists by binding to the receptor without activating it, therefore not producing a response. Therefore, the correct answer is that an agonist activates a receptor.

Correct Answer: C

Rationale: Phenytoin is commonly used as an anticonvulsant and antiarrhythmic medication. In addition to its approved uses, phenytoin has demonstrated effectiveness in managing neuropathic pain, which is pain caused by damage or dysfunction of the nervous system. While this use for phenytoin is off-label, it has been shown to be beneficial in certain individuals with neuropathic pain conditions. However, it is essential for a healthcare provider to prescribe phenytoin off-label for neuropathic pain, as the dosage and monitoring may differ from its standard use for epilepsy and arrhythmias.

Correct Answer: C

Rationale: Nitroglycerin is an antianginal medication that belongs to the class of nitrates. It is used to relieve chest pain or angina by dilating blood vessels, which reduces the workload of the heart and improves blood flow to the heart muscle. Nitroglycerin helps to relax and widen blood vessels, increasing the supply of oxygen and blood to the heart. It is often used for the treatment and prevention of angina attacks. In contrast, options A, B, and D are not antianginal medications or nitrates.