WBR0441
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| Author | [[PageAuthor::Serge Korjian M.D. (Reviewed by Alison Leibowitz) (Reviewed by Serge Korjian)]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Pharmacology |
| Sub Category | SubCategory::Cardiology |
| Prompt | [[Prompt::A 78-year-old man with heart failure is brought to the emergency department with complaints of severe shortness of breath at rest. Following evaluation, the patient is diagnosed with decompensated heart failure. His cardiologist decides to start the patient on a recombinant form of B-type natriuretic peptide. Which of the following agents most likely fits this description?]] |
| Answer A | AnswerA::Digitalis |
| Answer A Explanation | [[AnswerAExp::Digitalis, an inhibitor of Na+/K+/ATPase, indirectly causes accumulation intracellular Calcium by inactivating the Na+/Ca2+ exchanger, which requires an Na gradient to function.]] |
| Answer B | AnswerB::Nesiritide |
| Answer B Explanation | [[AnswerBExp::Nesiritide is a B-natriuretic peptide that may be used in patients with decompensated heart failure.]] |
| Answer C | AnswerC::Sodium Nitroprusside (SNP) |
| Answer C Explanation | [[AnswerCExp::Nitroprusside is a short-acting drug that increases the intracellular production of cGMP and nitrous oxide (NO).]] |
| Answer D | AnswerD::Diazoxide |
| Answer D Explanation | [[AnswerDExp::Diazoxide is a K+-channel opener that hyperpolarizes and relaxes vascular smooth muscle cells.]] |
| Answer E | AnswerE::Fenoldopam |
| Answer E Explanation | [[AnswerEExp::Fenoldopam is a dopamine D1 receptor agonist that acts as a systemic vasodilator. It is used to treat post-operative hypertension, and hypertensive crises requiring hospitalization. Due to it's mechanism of action, fenoldopam also relaxes renal vascular smooth muscles.]] |
| Right Answer | RightAnswer::B |
| Explanation | [[Explanation::Nesiritide, a recombinant B-type natriuretic peptide (BNP), is administered to reduce overload symptoms and left ventricular (LV) filling pressures in patients with acute decompensated heart failure. BNP is normally produced by the ventricular myocardium in response to overdistention of the ventricles. Nesiritide improves fluid homeostasis by decreasing systemic vascular resistance and central venous pressure. It also increases natriuresis by counterregulating the renin-angiotensin-aldoesterone system. Despite inital reports of reductions in mortality, large scale trials have demonstrated that nesiritide is not associated with a decrease in mortality or hospitalizations in patients with decompensated heart failure. Educational Objective: Nesiritide is a recombinant B-type natriuretic peptide used for patients with decompensated heart failure. |
| Approved | Approved::Yes |
| Keyword | WBRKeyword::Nesiritide, WBRKeyword::Decompensated heart failure, WBRKeyword::Natriuretic peptide, WBRKeyword::BNP, WBRKeyword::Heart failure |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |