A 31-year-old woman is brought to the emergency room after an apparent suicide attempt. She is unable to provide a history, but her husband reports that he found her at home severely confused and agitated. She reportedly mentioned swallowing several of her pills but was unable to provide additional details. Her husband reports that she has a history of Crohn disease, major depressive disorder, social anxiety disorder, and prior heroin and alcohol abuse. She has not taken heroin or alcohol for 5 years and attends Alcoholics Anonymous and Narcotics Anonymous regularly. She takes multiple medications but he is unable to recount which medications she takes and they are not in the electronic medical record. Her temperature is 103.9°F (39.9°C), blood pressure is 160/95 mmHg, pulse is 125/min, and respirations are 28/min. On exam, she appears agitated, diaphoretic, and is responding to internal stimuli. She has clonus in her bilateral feet. Pupils are 3 mm and reactive to light. Patellar and Achilles reflexes are 3+ bilaterally. She is given alprazolam for her agitation but she remains severely agitated and confused. Which of the following medications should be given to this patient?
Q612
A 62-year-old man presents to the ED complaining of severe eye pain that started a few hours ago. The patient reports that he fell asleep while watching TV on the couch and woke up with right-sided eye pain and blurry vision. His wife drove him to the emergency room. His wife reports that since they arrived the patient has also been complaining of intense nausea. The patient denies fever, headache, or visual floaters. He has a history of hypertension, hyperlipidemia, type II diabetes mellitus, and osteoarthritis. He takes aspirin, lisinopril, metformin, atorvastatin, and over-the-counter ibuprofen. His temperature is 99°F (37.2°C), blood pressure is 135/82 mmHg, and pulse is 78/min. On physical examination, the right eye is firm with an injected conjunctiva and a mildly cloudy cornea. The pupil is dilated at 6 mm and is non-reactive to light. Ocular eye movements are intact. Vision is 20/200 in the right eye and 20/40 in the left eye. The left eye exam is unremarkable. Which of the following is the most appropriate initial treatment?
Q613
A 53-year-old man presents to a physician with repeated episodes of joint pain and fever for the last 3 months. The pain is present in the knee joints and small joints of the hands bilaterally. He recorded his temperature at home which never increased above 37.8°C (100.0°F). The medical history is significant for an acute myocardial infarction 1 year ago, with sustained ventricular tachycardia as a complication, for which he has been taking procainamide. The vital signs are as follows: pulse 88/min, blood pressure 134/88 mm Hg, respiratory rate 13/min, and temperature 37.2°C (99.0°F). On physical examination, he has mild joint swelling. A radiologic evaluation of the involved joints does not suggest osteoarthritis or rheumatoid arthritis. Based on the laboratory evaluation, the physician suspects that the joint pain and fever may be due to the use of procainamide. Which of the following serologic finding is most likely to be present in this patient?
Q614
A 62-year-old Nigerian woman arrived 2 days ago to the US to visit her adult children from Nigeria. She is now brought to an urgent care center by her daughter for leg pain. Her right leg has been painful for 24 hours and is now causing her to limp. She denies any fevers, chills, or sweats and does not remember injuring her leg. She tells you she takes medications for hypertension and diabetes and occasionally for exertional chest pain. She has not had any recent chest pain. The right leg is swollen and tender. Flexion of the right ankle causes a worsening of the pain. Doppler ultrasonography reveals a large clot in a deep vein. Which of the following is the most appropriate course of action?
Q615
A 58-year-old man comes to the physician because of a sore throat and painful lesions in his mouth for the past few days. Six weeks ago, he underwent cardiac catheterization and stent implantation of the left anterior descending artery for treatment of acute myocardial infarction. Pharmacotherapy with aspirin and ticlopidine was started. His temperature is 38.1°C (100.6°F). Oral examination shows several shallow ulcers on the buccal mucosa. Laboratory studies show:
Hematocrit 41.5%
Leukocyte count 1,050/mm3
Segmented neutrophils 35%
Platelet count 175,000/mm3
Which of the following drugs is most likely responsible for this patient's current condition?
Q616
A 46-year-old man comes to the physician because of a 6-week history of fatigue and cramping abdominal pain. He works at a gun range. Examination shows pale conjunctivae and gingival hyperpigmentation. There is weakness when extending the left wrist against resistance. Further evaluation of this patient is most likely to show which of the following?
Q617
A 30-year-old woman presents to her physician for difficulty breathing. She states that this typically happens to her when she goes outside and improves with rest and staying indoors. Her symptoms are currently worse than usual. The patient has never seen a physician before and has no diagnosed past medical history. Her temperature is 99.5°F (37.5°C), blood pressure is 97/58 mmHg, pulse is 110/min, respirations are 25/min, and oxygen saturation is 88% on room air. Pulmonary function tests demonstrate a decreased inspiratory and expiratory flow rate. Which of the following is the best initial treatment for this patient?
Q618
A 63-year-old man presents to his primary care provider with colicky pain radiating to his left groin. The pain has been intermittent for several days. He has also been experiencing occasional burning pain in his hands and feet and frequent headaches. His past medical history is significant for an NSTEMI last year. He is currently taking atorvastatin and low dose aspirin. Today his temperature is 36.8°C (98.2°F), the heart rate is 103/min, the respiratory rate is 15/min, the blood pressure 135/85 mm Hg, and the oxygen saturation is 100% on room air. On physical exam, he appears gaunt and anxious. His heart is tachycardia with a regular rhythm and his lungs are clear to auscultation bilaterally. On abdominal exam he has hepatomegaly. A thorough blood analysis reveals a hemoglobin of 22 mg/dL and a significantly reduced EPO. Renal function and serum electrolytes are within normal limits. A urinalysis is positive for blood. A non-contrast CT shows a large kidney stone obstructing the left ureter. The patient’s pain is managed with acetaminophen and the stone passes with adequate hydration. It is sent to pathology for analysis. Additionally, a bone marrow biopsy is performed which reveals trilineage hematopoiesis and hypercellularity with a JAK2 mutation. Which medication would help prevent future episodes of nephrolithiasis?
Q619
A 59-year-old woman is referred to a neurologist for a hand tremor. Her symptoms began a few months prior to presentation and has progressively worsened. She noticed she was having difficulty drinking her coffee and writing in her notebook. The patient reports that her father also had a tremor but is unsure what type of tremor it was. She drinks 2-3 glasses of wine per week and only takes a multivitamin. Laboratory studies prior to seeing the neurologist demonstrated a normal basic metabolic panel and thyroid studies. On physical exam, there is a mid-amplitude 8 Hz frequency postural tremor of the right hand. The tremor is notable when the right hand is outstretched to the very end of finger-to-nose testing. Neurologic exam is otherwise normal. Which of the following is the best treatment option for this patient?
Q620
A 51-year-old woman with a history of paroxysmal atrial fibrillation comes to the physician for a follow-up visit. She feels well and wants to discuss pausing her only current medication, flecainide. Her pulse is 75/min and regular, blood pressure is 125/75 mm Hg. Physical examination shows no abnormalities. An ECG shows a PR interval of 180 ms, QRS time of 120 ms, and corrected QT interval of 440 ms. Which of the following ECG changes is most likely to be seen on cardiac stress testing in this patient?
Autonomic/CV Drugs US Medical PG Practice Questions and MCQs
Question 611: A 31-year-old woman is brought to the emergency room after an apparent suicide attempt. She is unable to provide a history, but her husband reports that he found her at home severely confused and agitated. She reportedly mentioned swallowing several of her pills but was unable to provide additional details. Her husband reports that she has a history of Crohn disease, major depressive disorder, social anxiety disorder, and prior heroin and alcohol abuse. She has not taken heroin or alcohol for 5 years and attends Alcoholics Anonymous and Narcotics Anonymous regularly. She takes multiple medications but he is unable to recount which medications she takes and they are not in the electronic medical record. Her temperature is 103.9°F (39.9°C), blood pressure is 160/95 mmHg, pulse is 125/min, and respirations are 28/min. On exam, she appears agitated, diaphoretic, and is responding to internal stimuli. She has clonus in her bilateral feet. Pupils are 3 mm and reactive to light. Patellar and Achilles reflexes are 3+ bilaterally. She is given alprazolam for her agitation but she remains severely agitated and confused. Which of the following medications should be given to this patient?
A. Naloxone
B. Ammonium chloride
C. N-acetylcysteine
D. Flumazenil
E. Cyproheptadine (Correct Answer)
Explanation: ***Cyproheptadine***
- The patient's presentation with **agitation**, **confusion**, **diaphoresis**, **hyperthermia** (103.9°F), **tachycardia**, **hypertension**, **clonus**, and **hyperreflexia** is highly suggestive of **serotonin syndrome**.
- **Cyproheptadine**, a **serotonin antagonist**, is the appropriate treatment for serotonin syndrome, especially when benzodiazepines like alprazolam have failed to control symptoms.
*Naloxone*
- **Naloxone** is an **opioid antagonist** used to reverse opioid overdose.
- While the patient has a history of heroin abuse, her vital signs and neurological examination (e.g., hyperreflexia, clonus) are inconsistent with opioid overdose, which typically presents with **respiratory depression** and **miosis**.
*Ammonium chloride*
- **Ammonium chloride** is an **acidifying agent** used in some poisonings to promote renal excretion of basic drugs.
- It is not indicated for the constellation of symptoms presented and can be dangerous if the specific toxin is unknown or if the patient has an acid-base disturbance.
*N-acetylcysteine*
- **N-acetylcysteine (NAC)** is the antidote for **acetaminophen overdose**.
- There is no clinical evidence in the patient's presentation to suggest acetaminophen toxicity.
*Flumazenil*
- **Flumazenil** is a **benzodiazepine receptor antagonist** used to reverse the effects of benzodiazepine overdose.
- While the patient was given alprazolam, her severe agitation and neurological findings (clonus, hyperreflexia) would not be indicative of benzodiazepine overdose; rather, benzodiazepines are used to *treat* the agitation seen in stimulant toxicity or serotonin syndrome.
Question 612: A 62-year-old man presents to the ED complaining of severe eye pain that started a few hours ago. The patient reports that he fell asleep while watching TV on the couch and woke up with right-sided eye pain and blurry vision. His wife drove him to the emergency room. His wife reports that since they arrived the patient has also been complaining of intense nausea. The patient denies fever, headache, or visual floaters. He has a history of hypertension, hyperlipidemia, type II diabetes mellitus, and osteoarthritis. He takes aspirin, lisinopril, metformin, atorvastatin, and over-the-counter ibuprofen. His temperature is 99°F (37.2°C), blood pressure is 135/82 mmHg, and pulse is 78/min. On physical examination, the right eye is firm with an injected conjunctiva and a mildly cloudy cornea. The pupil is dilated at 6 mm and is non-reactive to light. Ocular eye movements are intact. Vision is 20/200 in the right eye and 20/40 in the left eye. The left eye exam is unremarkable. Which of the following is the most appropriate initial treatment?
A. Topical epinephrine
B. Iridotomy
C. Intravenous acetazolamide (Correct Answer)
D. Topical prednisolone
E. Retinal photocoagulation
Explanation: ***Intravenous acetazolamide***
- The patient's signs and symptoms, including **severe eye pain, blurry vision, dilated fixed pupil, firm eye, and injected conjunctiva**, are classic for **acute angle-closure glaucoma (AACG)**.
- **Acetazolamide** (carbonic anhydrase inhibitor) reduces aqueous humor production and is a primary treatment to rapidly lower intraocular pressure in AACG.
*Topical epinephrine*
- **Epinephrine** can cause mydriasis (pupil dilation), which could further narrow the angle and worsen AACG.
- While it has some role in open-angle glaucoma, it is generally **contraindicated in AACG**.
*Iridotomy*
- **Laser peripheral iridotomy** is a definitive treatment for AACG to create an alternate pathway for aqueous humor flow, but it is a **surgical procedure** performed after medical stabilization.
- It is not the *initial* medical treatment for acute pressure reduction, but rather a subsequent intervention to prevent recurrence.
*Topical prednisolone*
- **Topical corticosteroids** like prednisolone are used to treat ocular inflammation but do not directly address the elevated intraocular pressure in AACG.
- In some cases, steroids can even **increase intraocular pressure**, making them inappropriate for this acute presentation.
*Retinal photocoagulation*
- **Retinal photocoagulation** is a laser procedure used to treat retinal conditions such as **diabetic retinopathy** or **retinal tears**.
- It is completely unrelated to the pathophysiology and treatment of acute angle-closure glaucoma.
Question 613: A 53-year-old man presents to a physician with repeated episodes of joint pain and fever for the last 3 months. The pain is present in the knee joints and small joints of the hands bilaterally. He recorded his temperature at home which never increased above 37.8°C (100.0°F). The medical history is significant for an acute myocardial infarction 1 year ago, with sustained ventricular tachycardia as a complication, for which he has been taking procainamide. The vital signs are as follows: pulse 88/min, blood pressure 134/88 mm Hg, respiratory rate 13/min, and temperature 37.2°C (99.0°F). On physical examination, he has mild joint swelling. A radiologic evaluation of the involved joints does not suggest osteoarthritis or rheumatoid arthritis. Based on the laboratory evaluation, the physician suspects that the joint pain and fever may be due to the use of procainamide. Which of the following serologic finding is most likely to be present in this patient?
A. Decreased serum C4 level
B. Presence of anti-dsDNA antibodies
C. Presence of anti-histone antibodies (Correct Answer)
D. Decreased serum C3 level
E. Presence of anti-Sm antibodies
Explanation: ***Presence of anti-histone antibodies***
- The patient's history of taking **procainamide** along with symptoms of **joint pain** and **low-grade fever** strongly suggests **drug-induced lupus erythematosus (DILE)**.
- **Anti-histone antibodies** are present in 95% of patients with DILE and are considered a hallmark of the condition.
*Decreased serum C4 level*
- **Decreased C4 levels** are more characteristic of **classic systemic lupus erythematosus (SLE)**, particularly in active disease.
- In DILE, complement levels (C3 and C4) are typically **normal** or only mildly decreased.
*Presence of anti-dsDNA antibodies*
- **Anti-dsDNA antibodies** are highly specific for **classic SLE** and are rarely found in DILE.
- Their presence would suggest a diagnosis of SLE rather than drug-induced disease.
*Decreased serum C3 level*
- Similar to decreased C4, **low C3 levels** are indicative of **classic SLE** due to immune complex deposition and complement consumption.
- In DILE, complement levels are generally **preserved**.
*Presence of anti-Sm antibodies*
- **Anti-Smith (Sm) antibodies** are also highly specific for **classic SLE** and are considered a diagnostic criterion.
- They are not typically found in patients with DILE.
Question 614: A 62-year-old Nigerian woman arrived 2 days ago to the US to visit her adult children from Nigeria. She is now brought to an urgent care center by her daughter for leg pain. Her right leg has been painful for 24 hours and is now causing her to limp. She denies any fevers, chills, or sweats and does not remember injuring her leg. She tells you she takes medications for hypertension and diabetes and occasionally for exertional chest pain. She has not had any recent chest pain. The right leg is swollen and tender. Flexion of the right ankle causes a worsening of the pain. Doppler ultrasonography reveals a large clot in a deep vein. Which of the following is the most appropriate course of action?
A. Direct oral anticoagulant (DOAC) therapy (Correct Answer)
B. Initiation of heparin followed by bridge to warfarin
C. Initiation of heparin
D. Initiation of warfarin
E. Treatment with tissue plasminogen activator
Explanation: ***Direct oral anticoagulant (DOAC) therapy***
- **DOACs are the first-line treatment** for acute DVT in most patients according to current guidelines (ACCP, ASH, ESC 2023-2024).
- Options include **rivaroxaban, apixaban, edoxaban, or dabigatran**, which provide rapid anticoagulation without the need for bridging therapy or routine INR monitoring.
- This patient has **provoked DVT** (recent long-distance travel from Nigeria), standard cardiovascular risk factors, and no contraindications to DOACs.
- DOACs offer **comparable efficacy** to warfarin with **lower risk of major bleeding** and greater convenience for patients.
*Initiation of heparin followed by bridge to warfarin*
- The **heparin-warfarin bridge** was standard therapy in the past but is now considered **second-line** for most patients.
- This approach is now **reserved for specific situations**: severe renal impairment (CrCl <30 mL/min), antiphospholipid syndrome, mechanical heart valves, or when DOACs are contraindicated or unavailable.
- The patient has **exertional chest pain** (angina), which is related to coronary artery disease and does **not** constitute a contraindication to DOACs or an indication for warfarin.
- The heparin bridge adds complexity, requires hospitalization or close monitoring, and delays transition to oral therapy.
*Initiation of heparin*
- **Heparin monotherapy** is insufficient for long-term DVT management and is only used as a bridge to oral anticoagulation in specific scenarios.
- While it provides immediate anticoagulation, discontinuing heparin without oral anticoagulant coverage leads to high recurrence risk.
- Modern practice favors **direct initiation of DOACs**, eliminating the need for parenteral therapy in most cases.
*Initiation of warfarin*
- **Warfarin monotherapy** at initiation is contraindicated because warfarin has a **delayed onset of action** (5-7 days) due to its mechanism of depleting vitamin K-dependent clotting factors.
- Starting warfarin alone creates a paradoxical **prothrombotic state** in the first 24-48 hours (due to rapid depletion of protein C) and leaves the patient unprotected from clot propagation.
- Warfarin requires **bridging with heparin** if used, but DOACs are preferred in current practice.
*Treatment with tissue plasminogen activator*
- **Thrombolytic therapy** (tPA, catheter-directed thrombolysis) is reserved for **life- or limb-threatening DVT** such as phlegmasia cerulea dolens or massive pulmonary embolism with hemodynamic instability.
- This patient has **uncomplicated DVT** without signs of limb-threatening ischemia, making anticoagulation the appropriate first-line therapy.
- Thrombolysis carries significant **bleeding risk** and is not indicated for routine DVT management.
Question 615: A 58-year-old man comes to the physician because of a sore throat and painful lesions in his mouth for the past few days. Six weeks ago, he underwent cardiac catheterization and stent implantation of the left anterior descending artery for treatment of acute myocardial infarction. Pharmacotherapy with aspirin and ticlopidine was started. His temperature is 38.1°C (100.6°F). Oral examination shows several shallow ulcers on the buccal mucosa. Laboratory studies show:
Hematocrit 41.5%
Leukocyte count 1,050/mm3
Segmented neutrophils 35%
Platelet count 175,000/mm3
Which of the following drugs is most likely responsible for this patient's current condition?
A. Enoxaparin
B. Aspirin
C. Abciximab
D. Apixaban
E. Ticlopidine (Correct Answer)
Explanation: **Ticlopidine**
* This patient presents with **neutropenia** (leukocyte count 1,050/mm3 with 35% segmented neutrophils) and **oral ulcers**, which signifies a severe adverse drug reaction.
* **Ticlopidine** is a P2Y12 inhibitor that carries a known risk of severe adverse effects, including **neutropenia** and **thrombotic thrombocytopenic purpura (TTP).**
*Enoxaparin*
* Enoxaparin is a **low molecular weight heparin** used for anticoagulation.
* It is associated with **heparin-induced thrombocytopenia (HIT)**, but not typically neutropenia or oral ulcers.
*Aspirin*
* Aspirin is a **COX inhibitor** and an antiplatelet agent.
* Common side effects include **gastrointestinal upset** and bleeding, but it does not typically cause neutropenia or oral ulcers.
*Abciximab*
* Abciximab is a **glycoprotein IIb/IIIa inhibitor** used as an antiplatelet agent.
* Its primary adverse effect is **bleeding** and **thrombocytopenia**, but not neutropenia or oral ulcers.
*Apixaban*
* Apixaban is a **direct oral anticoagulant (DOAC)**, specifically a Factor Xa inhibitor.
* It is primarily associated with an increased risk of **bleeding** and does not typically cause neutropenia or oral ulcers.
Question 616: A 46-year-old man comes to the physician because of a 6-week history of fatigue and cramping abdominal pain. He works at a gun range. Examination shows pale conjunctivae and gingival hyperpigmentation. There is weakness when extending the left wrist against resistance. Further evaluation of this patient is most likely to show which of the following?
A. Beta‑2 microglobulin in urine
B. Septal thickening on chest x-ray
C. Basophilic stippling of erythrocytes (Correct Answer)
D. White bands across the nails
E. Increased total iron binding capacity
Explanation: ***Basophilic stippling of erythrocytes***
- This patient's symptoms (fatigue, anemic conjunctivae, abdominal pain, gingival hyperpigmentation, wrist drop) and occupational exposure (gun range) are classic signs of **lead poisoning**.
- **Basophilic stippling** is a characteristic finding on a peripheral blood smear in lead poisoning, resulting from the aggregation of ribosomal RNA due to impaired heme synthesis.
*Beta‑2 microglobulin in urine*
- **Beta-2 microglobulinuria** is typically associated with **renal tubular damage** or increased cell turnover (e.g., multiple myeloma), not directly with lead poisoning.
- While lead toxicity can affect the kidneys in the long term, this is not the most direct or common initial diagnostic finding for acute or subacute lead poisoning.
*Septal thickening on chest x-ray*
- **Septal thickening** on a chest x-ray suggests conditions like **pulmonary fibrosis**, **interstitial lung disease**, or cardiac conditions causing fluid overload.
- It is not a typical manifestation or diagnostic feature of lead poisoning.
*White bands across the nails*
- **White bands across the nails**, known as **Mees' lines**, are associated with **arsenic poisoning**, not lead poisoning.
- The clinical picture presented strongly points away from arsenic toxicity.
*Increased total iron binding capacity*
- **Increased total iron binding capacity (TIBC)** is characteristic of **iron deficiency anemia**, as the body attempts to make more transferrin to capture what little iron is available.
- In lead poisoning, TIBC is usually normal or decreased, as lead inhibits heme synthesis, leading to anemia but not necessarily iron deficiency.
Question 617: A 30-year-old woman presents to her physician for difficulty breathing. She states that this typically happens to her when she goes outside and improves with rest and staying indoors. Her symptoms are currently worse than usual. The patient has never seen a physician before and has no diagnosed past medical history. Her temperature is 99.5°F (37.5°C), blood pressure is 97/58 mmHg, pulse is 110/min, respirations are 25/min, and oxygen saturation is 88% on room air. Pulmonary function tests demonstrate a decreased inspiratory and expiratory flow rate. Which of the following is the best initial treatment for this patient?
A. Epinephrine
B. Albuterol (Correct Answer)
C. Diphenhydramine
D. Intubation
E. Prednisone
Explanation: ***Albuterol***
- The patient presents with **acute respiratory distress** involving bronchoconstriction, indicated by difficulty breathing, low oxygen saturation (88%), and decreased inspiratory and expiratory flow rates, consistent with an **asthma exacerbation**.
- **Albuterol**, a short-acting beta-2 agonist (SABA), is the first-line treatment for acute asthma bronchodilation due to its **rapid onset of action**.
*Epinephrine*
- While epinephrine can cause bronchodilation, its primary use is for severe allergic reactions or **anaphylaxis**, which is not directly indicated here.
- Its use in asthma is typically reserved for cases where **anaphylaxis** is suspected to be contributing or in severe, refractory bronchospasm.
*Diphenhydramine*
- **Diphenhydramine** is an antihistamine used for allergic reactions, but it does not treat **bronchoconstriction** and is not indicated for acute respiratory distress.
- It can cause sedation, which could further complicate respiratory management in an acutely breathless patient.
*Intubation*
- **Intubation** is a last resort management for respiratory failure, when medical therapies have failed to improve oxygenation or ventilation.
- Although the patient's oxygen saturation is low, initial medical management should be attempted before considering invasive interventions like intubation.
*Prednisone*
- **Prednisone** is a corticosteroid used to reduce inflammation in asthma exacerbations, but its onset of action is slow (hours to days).
- It is often used in conjunction with bronchodilators for moderate to severe exacerbations but is not the **best initial treatment** for immediate symptom relief.
Question 618: A 63-year-old man presents to his primary care provider with colicky pain radiating to his left groin. The pain has been intermittent for several days. He has also been experiencing occasional burning pain in his hands and feet and frequent headaches. His past medical history is significant for an NSTEMI last year. He is currently taking atorvastatin and low dose aspirin. Today his temperature is 36.8°C (98.2°F), the heart rate is 103/min, the respiratory rate is 15/min, the blood pressure 135/85 mm Hg, and the oxygen saturation is 100% on room air. On physical exam, he appears gaunt and anxious. His heart is tachycardia with a regular rhythm and his lungs are clear to auscultation bilaterally. On abdominal exam he has hepatomegaly. A thorough blood analysis reveals a hemoglobin of 22 mg/dL and a significantly reduced EPO. Renal function and serum electrolytes are within normal limits. A urinalysis is positive for blood. A non-contrast CT shows a large kidney stone obstructing the left ureter. The patient’s pain is managed with acetaminophen and the stone passes with adequate hydration. It is sent to pathology for analysis. Additionally, a bone marrow biopsy is performed which reveals trilineage hematopoiesis and hypercellularity with a JAK2 mutation. Which medication would help prevent future episodes of nephrolithiasis?
A. Hydroxyurea
B. Probenecid
C. Thiazide
D. Antihistamines
E. Allopurinol (Correct Answer)
Explanation: ***Allopurinol***
- The patient's presentation, including **hypercellularity** with a **JAK2 mutation**, extremely high hemoglobin (22 mg/dL), and hepatomegaly, is consistent with **polycythemia vera**. This condition leads to increased cell turnover and elevated uric acid levels, predisposing to **uric acid nephrolithiasis**.
- **Allopurinol** inhibits xanthine oxidase, reducing the production of uric acid and preventing the formation of uric acid stones, which is crucial in patients with myeloproliferative disorders like polycythemia vera.
*Hydroxyurea*
- **Hydroxyurea** is a cytoreductive agent used in polycythemia vera to lower blood cell counts, thereby reducing the risk of thrombotic events and controlling symptoms.
- While it manages the underlying myeloproliferative disorder, it does not directly prevent **uric acid stone formation** and can sometimes increase uric acid levels during initial cytoreduction due to rapid cell lysis.
*Probenecid*
- **Probenecid** is a uricosuric agent that increases the excretion of uric acid in the urine.
- It is used in patients with **gout** or hyperuricemia who are underexcretors of uric acid, but it can paradoxically increase the risk of uric acid nephrolithiasis due to higher urinary uric acid concentrations.
*Thiazide*
- **Thiazide diuretics** reduce urinary calcium excretion and are primarily used to prevent **calcium-containing kidney stones**, such as calcium oxalate or calcium phosphate stones.
- They are not indicated for the prevention of **uric acid stones**, which are the likely type in this patient given his polycythemia vera.
*Antihistamines*
- **Antihistamines** block histamine receptors and are primarily used to treat allergic reactions, insomnia, or nausea.
- They have no role in the prevention or treatment of **nephrolithiasis** or conditions like polycythemia vera.
Question 619: A 59-year-old woman is referred to a neurologist for a hand tremor. Her symptoms began a few months prior to presentation and has progressively worsened. She noticed she was having difficulty drinking her coffee and writing in her notebook. The patient reports that her father also had a tremor but is unsure what type of tremor it was. She drinks 2-3 glasses of wine per week and only takes a multivitamin. Laboratory studies prior to seeing the neurologist demonstrated a normal basic metabolic panel and thyroid studies. On physical exam, there is a mid-amplitude 8 Hz frequency postural tremor of the right hand. The tremor is notable when the right hand is outstretched to the very end of finger-to-nose testing. Neurologic exam is otherwise normal. Which of the following is the best treatment option for this patient?
A. Levodopa-carbidopa
B. Alprazolam
C. Botulinum toxin injection
D. Deep brain stimulation
E. Primidone (Correct Answer)
Explanation: ***Primidone***
- This patient's symptoms are highly suggestive of **essential tremor**, characterized by a **postural or kinetic tremor**, often familial, and affecting daily activities like drinking and writing. **Primidone** is a first-line treatment for essential tremor.
- The exam findings of a **mid-amplitude 8 Hz frequency postural tremor** and worsening during action like finger-to-nose testing, along with the absence of other neurological deficits and a normal workup, support this diagnosis.
*Levodopa-carbidopa*
- This combination therapy is the gold standard for treating **Parkinson's disease**, which is characterized by a **resting tremor**, bradykinesia, rigidity, and postural instability.
- The patient's tremor is primarily **postural/kinetic**, not resting, and other parkinsonian symptoms are absent.
*Alprazolam*
- **Benzodiazepines** like alprazolam can sometimes be used to treat anxiety, which may exacerbate tremors, or for tremors associated with severe anxiety or alcohol withdrawal.
- It is generally not considered a primary treatment for essential tremor due to its **sedative side effects** and potential for dependence.
*Botulinum toxin injection*
- **Botulinum toxin** can be effective for tremors that are focal and severe, especially when other medications have failed or are not tolerated.
- It is typically used for specific, localized tremors and is not usually the first-line systemic treatment for generalized essential tremor.
*Deep brain stimulation*
- **Deep brain stimulation (DBS)** is a surgical option reserved for **severe, medication-refractory essential tremor** or Parkinson's disease.
- It is an invasive procedure and is not considered a first-line treatment for a newly diagnosed tremor, especially before trying conservative medical management.
Question 620: A 51-year-old woman with a history of paroxysmal atrial fibrillation comes to the physician for a follow-up visit. She feels well and wants to discuss pausing her only current medication, flecainide. Her pulse is 75/min and regular, blood pressure is 125/75 mm Hg. Physical examination shows no abnormalities. An ECG shows a PR interval of 180 ms, QRS time of 120 ms, and corrected QT interval of 440 ms. Which of the following ECG changes is most likely to be seen on cardiac stress testing in this patient?
A. Decreased maximal heart rate
B. Prolonged QRS complex (Correct Answer)
C. Shortened PR interval
D. False-positive ST-segment depression
E. Prolonged QTc interval
Explanation: ***Prolonged QRS complex***
- **Flecainide** is a class Ic antiarrhythmic that **blocks fast sodium channels** in myocardial cells, slowing conduction in the atria, ventricles, and His-Purkinje system.
- Its effects are **use-dependent**, meaning the drug binds more effectively to channels that are frequently activated (i.e., at higher heart rates), leading to a **further widening of the QRS complex** during exercise.
*Decreased maximal heart rate*
- While some class II antiarrhythmics (beta-blockers) can decrease maximal heart rate, **flecainide** primarily affects cardiac conduction and does not significantly impact heart rate response to stress.
- The ECG does not suggest sinus node dysfunction that would limit heart rate increase with activity.
*Shortened PR interval*
- Flecainide typically **prolongs the PR interval** by slowing conduction through the atrioventricular (AV) node.
- Exercise would likely exacerbate this effect rather than shorten the PR interval.
*False-positive ST-segment depression*
- While wide QRS complexes (as may occur with flecainide-induced conduction slowing) can cause abnormal ST-segment morphology, the **most prominent and characteristic effect** of flecainide during stress testing is **progressive QRS widening** due to use-dependent sodium channel blockade.
- False-positive ST changes are a nonspecific finding and not the hallmark ECG change expected with flecainide during exercise.
*Prolonged QTc interval*
- Flecainide is generally known to **not significantly prolong the QT interval**; in some cases, it may even shorten it due to its effect on action potential duration.
- Other antiarrhythmics like Class III agents (e.g., amiodarone, sotalol) are more commonly associated with QTc prolongation.