WBR0401
| Author | [[PageAuthor::Gonzalo A. Romero, M.D. [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Pharmacology |
| Sub Category | SubCategory::Cardiology, SubCategory::Vascular |
| Prompt | [[Prompt::A novel drug is being developed by a group of basic science researchers. The drug is being studied under animal models using specific cardiovascular receptors. The research team measures the drug’s effects on the ventricular membrane potential. They determine that the drug increases the action potential duration (APD) by increasing the effective refractory period (ERP). Detail molecular studies determine that the drug works by blocking the potassium channels. Which of the following drugs is an analogue of the novel drug?]] |
| Answer A | AnswerA::Sotalol |
| Answer A Explanation | [[AnswerAExp::Correct. Sotalol is a potasium channel blocker]] |
| Answer B | AnswerB::Metoprolol |
| Answer B Explanation | [[AnswerBExp::Incorrect. Metoprolol is a beta-blocker (class II) anti-arrhythmic.]] |
| Answer C | AnswerC::Lidocaine |
| Answer C Explanation | [[AnswerCExp::Incorrect. Lidocaine is a sodium channel blocker, which is a class IA anti-arrhythmic.]] |
| Answer D | AnswerD::Verapamil |
| Answer D Explanation | [[AnswerDExp::Incorrect. Verapamil is a calcium channel blocker, which is a class IV anti-arrhythmic.]] |
| Answer E | AnswerE::Mexiletine |
| Answer E Explanation | [[AnswerEExp::Incorrect.Mexiletine is a sodium channel blocker, which belongs to the class IB anti-arrhythmic drugs.]] |
| Right Answer | RightAnswer::A |
| Explanation | [[Explanation::The anti-arrhythmic classification is commonly tested on USMLE. The classification is as follows
Educational Objective: |
| Approved | Approved::Yes |
| Keyword | |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |
