WBR242

Author	[[PageAuthor::Gerald Chi (Reviewed by Yazan Daaboul, M.D.)]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Pharmacology
Sub Category	SubCategory::Cardiology
Prompt	[[Prompt::A 58-year-old hypertensive woman presents to her physician's office for a routine check-up. Upon review of systems, the women states that she is asymptomatic and has no complaints. She reports that she was prescribed an antihypertensive drug by another primary care physician 6 months ago and has been taking one tablet each day. In the clinic, she is afebrile with a blood pressure of 118/80 mmHg, heart rate of 58/min, and respiratory rate of 14/min. Physical examination is unremarkable. Laboratory work-up demonstrates a total cholesterol concentration of 220 mg/dl, LDL-C of 100 mg/dl, HDL-C of 50 mg/dl, triglyceride concentration of 350 mg/dl. The patient is surprised and states that she never had abnormal lipid profiles in the past. The physician suspects the patient's abnormal findings are related to an adverse effect of the drug she has been prescribed. Which of the following antihypertensive drugs is the patient most likely receiving?]]
Answer A	AnswerA::Prazosin
Answer A Explanation	AnswerAExp::Prazosin is an alpha-1 adrenergic antagonist (alpha blocker). Prazosin is typically associated with orthostatic hypotension and nasal congestion.
Answer B	AnswerB::Lisinopril
Answer B Explanation	AnswerBExp::Lisinopril is an angiotensin-converting enzyme inhibitor (ACE-I). ACE-I are typically associated with cough and hyperkalemia.
Answer C	AnswerC::Clonidine
Answer C Explanation	AnswerCExp::Clonidine is a centrally acting alpha-2 agonist. Clonidine is typically associated with lightheadednes, dry mouth, dizziness, constipation, and hypotension.
Answer D	AnswerD::Atenolol
Answer D Explanation	AnswerDExp::Atenolol is a non-selective beta blocker. Beta blockers are typically associated with bradycardia and dyslipidemia.
Answer E	AnswerE::Verapamil
Answer E Explanation	AnswerEExp::Verapamil is a non-dihydropyridine calcium channel blocker (CCB). Non-dihydropyridine CCBs are typically associated with constipation and GI distress.
Right Answer	RightAnswer::D
Explanation	[[Explanation::The patient is most likely receiving a beta blocker. Beta-blockers are antihypertensive, sympatholytic agents that reduce the cardiac output by binding to beta-adrenoreceptors present in the cardiac nodal tissue, thereby decreasing the number of unoccupied receptors available for norepinephrine and epinephrine to bind to. Beta blockers bind to may be either cardioselective (B1 blockade > B2 blockade) or non-selective (both B1 and B2 blockade). They are indicated in hypertension as well as stable/unstable angina and in the acute phase of myocardial infarction (MI) among stable patients and for the long-term management of MI patients. Beta blockers are also indicated in arrhythmias, bleeding esophageal varices, migraine, and early/advanced heart failure, where some beta blockers have proven efficacy in reducing mortality in heart failure patients (metoprolol, bisoprolol, and carvedilol). Adverse effects associated with the undesired β2-adrenergic antagonism include bradycardia (heart rate < 60/min), bronchospasm, peripheral vasoconstriction, and alteration of glucose and lipid metabolism. These effects are typically observed with administration of non-selective beta blockers or at higher doses of cardioselective beta blockers. Educational Objective: Beta-blockers are antihypertensive, sympatholytic agents that reduce the cardiac output by binding to beta-adrenoreceptors present in the cardiac nodal tissue, thereby decreasing the number of unoccupied receptors available for norepinephrine and epinephrine to bind to. Adverse effects associated with the undesired β2-adrenergic antagonism include bradycardia (heart rate < 60/min), bronchospasm, peripheral vasoconstriction, and alteration of glucose and lipid metabolism. References: Helfand M, Peterson K, Christensen V, et al. Drug Class Review: Beta Adrenergic Blockers: Final Report Update 4 [Internet]. Portland (OR): Oregon Health & Science University; 2009 Jul. Available from: http://www.ncbi.nlm.nih.gov/books/NBK47172/ First Aid 2015 page 256]]
Approved	Approved::Yes
Keyword	WBRKeyword::Atenolol, WBRKeyword::Beta blockers, WBRKeyword::Adverse effects, WBRKeyword::Drug class, WBRKeyword::Pharmacologic therapy, WBRKeyword::Bradycardia, WBRKeyword::Lipid profile
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