A 26-year-old G1P0 woman at 40 weeks estimated gestational age presents after experiencing labor pains. Pregnancy has been uncomplicated so far. Rupture of membranes occurs, and a transvaginal delivery is performed under epidural anesthesia, and the baby is delivered alive and healthy. The patient voids a few hours after the delivery and complains of mild irritation at the injection site on her back. On the second day, she complains of a severe headache over the back of her head. The headache is associated with pain and stiffness in the neck. Her headache is aggravated by sitting up or standing and relieved by lying down. The pain is relieved slightly by acetaminophen and ibuprofen. The patient is afebrile. Her vital signs include: pulse 100/min, respiratory rate 18/min, and blood pressure 128/84 mm Hg. Which of the following statements is the most accurate regarding this patient’s condition?
Q362
A 25-year-old man is admitted to the intensive care unit with confusion and severe dyspnea at rest which started 3 hours ago. The symptoms worsen when the patient lies down and improve in the sitting position. The patient has a history of cocaine abuse. The patient's blood pressure is 75/50 mm Hg, the heart rate is 95/min, the respiratory rate is 22/min, the temperature is 36.5℃ (97.7℉), and the SpO2 is 89% on room air. On physical examination, there is peripheral cyanosis with pallor, coldness of the extremities, diaphoresis, and marked peripheral veins distension. Lung auscultation reveals bilateral absence of the lung sounds over the lower lobes and widespread rales over the other lung fields. On cardiac auscultation, there is a protodiastolic gallop and S2 accentuation best heard in the second intercostal space at the left sternal border. Abdominal palpation shows signs of intraperitoneal fluid accumulation and hepatomegaly. Considering the low cardiac output, milrinone is administered as an inotropic agent. What is the most likely side effect which can result from administration of milrinone?
Q363
A 61-year-old woman presents to the emergency room with left leg pain and swelling. She recently returned to the United States from a trip to India. Her past medical history is notable for osteoarthritis in both hips, lumbar spinal stenosis, and hypertension. She takes lisinopril. Her temperature is 99°F (37.2°C), blood pressure is 140/85 mmHg, pulse is 110/min, and respirations are 24/min. On examination, her left calf is larger than her right calf. A lower extremity ultrasound demonstrates a deep venous thrombosis in the left femoral vein. Results from a complete blood count are within normal limits. She is admitted and started on unfractionated heparin. Seven days later, she presents with a dark erythematous skin lesion on her left thigh and worsening left leg swelling. A lower extremity ultrasound demonstrates a persistent deep venous thrombosis in the left femoral vein as well as a new deep venous thrombosis in the left popliteal vein. Results of a complete blood count are shown below:
Hemoglobin: 13.1 g/dL
Hematocrit: 38%
Leukocyte count: 9,600/mm^3 with normal differential
Platelet count: 74,000/mm^3
A medication with which of the following mechanisms of action is most appropriate to initiate in this patient after stopping the heparin?
Q364
A 26-year-old woman is brought to the emergency department after a motor vehicle accident. She was driving on the highway when she was struck by a van. At the hospital she was conscious but was bleeding heavily from an open wound in her left leg. Pulse is 120/min and blood pressure is 96/68 mm Hg. She receives 3 L of intravenous saline and her pulse slowed to 80/min and blood pressure elevated to 116/70 mm Hg. The next morning she is found to have a hemoglobin of 6.2 g/dL. Her team decides to transfuse 1 unit of packed RBCs. Twenty minutes into the transfusion she develops a diffuse urticarial rash, wheezing, fever, and hypotension. The transfusion is immediately stopped and intramuscular epinephrine is administered. Which of the following scenarios is most consistent with this patient's reaction to the blood transfusion?
Q365
A 60-year-old woman presents to the emergency room with chest pain that started 20 minutes ago while watching television at home. The pain is substernal and squeezing in nature. She rates the pain as 6/10 and admits to having similar pain in the past with exertion. Her past medical history is significant for diabetes mellitus that is controlled with metformin. The physical examination is unremarkable. An electrocardiogram (ECG) shows ST-segment depression in the lateral leads. She is started on aspirin, nitroglycerin, metoprolol, unfractionated heparin, and insulin. She is asked not to take metformin while at the hospital. Three sets of cardiac enzymes are negative.
Lab results are given below:
Serum glucose 88 mg/dL
Sodium 142 mEq/L
Potassium 3.9 mEq/L
Chloride 101 mEq/L
Serum creatinine 1.2 mg/dL
Blood urea nitrogen 22 mg/dL
Cholesterol, total 170 mg/dL
HDL-cholesterol 40 mg/dL
LDL-cholesterol 80 mg/dL
Triglycerides 170 mg/dL
Hematocrit 38%
Hemoglobin 13 g/dL
Leucocyte count 7,500/mm3
Platelet count 185,000 /mm3
Activated partial thromboplastin time (aPTT) 30 seconds
Prothrombin time (PT) 12 seconds
Urinalysis
Glucose negative
Ketones negative
Leucocytes negative
Nitrites negative
Red blood cells (RBC) negative
Casts negative
An echocardiogram reveals left ventricular wall motion abnormalities. With the pain subsiding, she was admitted and the medications were continued. A coronary angiography is planned in 4 days. In addition to regular blood glucose testing, which of the following should be closely monitored in this patient?
Q366
A 2-year-old boy had increased bleeding during a circumcision. His birth and delivery were uncomplicated, and his mother had no issues with prolonged bleeding during labor. Of note, his maternal grandfather has a history of bleeding complications. The boy's vital signs are stable and physical examination is notable for scattered bruises on his lower extremities. The lab results are as follows:
Hemoglobin 12.8 gm %
Hematocrit 35.4%
WBC 8400/mm3
Platelets 215 x 109/L
PT 14 s
PTT 78 s
What is the most likely diagnosis?
Q367
A 52-year-old woman is brought to the emergency department for a severe, sudden-onset headache, light-sensitivity, and neck stiffness that began 30 minutes ago. A CT scan of the head shows hyperdensity between the arachnoid mater and the pia mater. The patient undergoes an endovascular procedure. One week later, she falls as she is returning from the bathroom. Neurologic examination shows 3/5 strength in the right lower extremity and 5/5 in the left lower extremity. Treatment with which of the following drugs is most likely to have prevented the patient's current condition?
Q368
A 57-year-old man with type 2 diabetes mellitus comes to the physician for a follow-up evaluation. He was recently diagnosed with hyperlipidemia, for which he takes several medications. His serum total cholesterol concentration is 295 mg/dL and serum high-density lipoprotein concentration is 19 mg/dL (N: > 40 mg/dL). The physician prescribes an additional drug that decreases hepatic production of triglycerides and reduces the release of VLDL and LDL through the inhibition of diacylglycerol acyltransferase 2. This patient should be advised to do which of the following?
Q369
A 20-year-old man presents to his primary care provider with a history of recurrent cough, wheezing, and breathlessness since early childhood. He was previously diagnosed with allergic rhinitis and bronchial asthma. For his allergic rhinitis, he uses intranasal fluticasone. For his asthma, he uses an albuterol inhaler as a rescue inhaler. It is decided to initiate a new medication for daily use. Which of the following medications, with its corresponding mechanism, is the next best step in therapy?
Q370
Two weeks after being hospitalized for acute pancreatitis, a 36-year-old man comes to the physician for a follow-up examination. Multiple family members have coronary artery disease. Physical examination shows multiple, yellow papular lesions on both upper eyelids. Fasting serum lipid studies show:
Total cholesterol 280 mg/dl
HDL-cholesterol 40 mg/dl
LDL-cholesterol 185 mg/dl
Triglycerides 1080 mg/dl
Treatment with gemfibrozil is initiated. The expected beneficial effect of this drug is most likely due to which of the following mechanisms of action?
Autonomic/CV Drugs US Medical PG Practice Questions and MCQs
Question 361: A 26-year-old G1P0 woman at 40 weeks estimated gestational age presents after experiencing labor pains. Pregnancy has been uncomplicated so far. Rupture of membranes occurs, and a transvaginal delivery is performed under epidural anesthesia, and the baby is delivered alive and healthy. The patient voids a few hours after the delivery and complains of mild irritation at the injection site on her back. On the second day, she complains of a severe headache over the back of her head. The headache is associated with pain and stiffness in the neck. Her headache is aggravated by sitting up or standing and relieved by lying down. The pain is relieved slightly by acetaminophen and ibuprofen. The patient is afebrile. Her vital signs include: pulse 100/min, respiratory rate 18/min, and blood pressure 128/84 mm Hg. Which of the following statements is the most accurate regarding this patient’s condition?
A. A blockage of CSF is the cause of this patient’s headache
B. An infection is present at the epidural injection site
C. This patient’s condition can resolve on its own (Correct Answer)
D. Excessive bed rest will worsen this patient’s condition
E. Immediate intervention is required
Explanation: ***This patient’s condition can resolve on its own***
- The symptoms describe a **post-dural puncture headache (PDPH)**, a common complication of epidural anesthesia, which is often **self-limiting** within days to weeks.
- Initial management involves conservative measures like bed rest, hydration, and analgesics, as many cases resolve without specific interventions.
*A blockage of CSF is the cause of this patient’s headache*
- PDPH is caused by a **leakage of cerebrospinal fluid (CSF)** through the dura mater, leading to **intracranial hypotension**, not a blockage of CSF flow.
- The leakage reduces CSF pressure, causing the brain to sag when upright, stretching pain-sensitive structures like meninges and blood vessels.
*An infection is present at the site of epidural injection site*
- While localized irritation is mentioned, there are no signs of infection such as **fever**, **erythema**, or **purulent discharge** at the injection site, making infection less likely.
- The headache characteristics (positional, severe, neck stiffness) are classic for PDPH, not typically seen in local epidural infections, which would also present with systemic signs.
*Excessive bed rest will worsen this patient’s condition*
- **Bed rest** typically **improves** the symptoms of PDPH by reducing the gravitational pull on the intracranial structures, thereby alleviating the headache.
- Prolonged bed rest is generally recommended in the acute phase, often combined with hydration and caffeine, to help manage symptoms, not worsen them.
*Immediate intervention is required*
- While severe PDPH can be debilitating, immediate invasive intervention (like an **epidural blood patch**) is usually reserved for cases that are **severe and refractory to conservative management** after 24-48 hours.
- Many patients experience spontaneous resolution or significant improvement with conservative measures, making immediate invasive intervention typically unnecessary.
Question 362: A 25-year-old man is admitted to the intensive care unit with confusion and severe dyspnea at rest which started 3 hours ago. The symptoms worsen when the patient lies down and improve in the sitting position. The patient has a history of cocaine abuse. The patient's blood pressure is 75/50 mm Hg, the heart rate is 95/min, the respiratory rate is 22/min, the temperature is 36.5℃ (97.7℉), and the SpO2 is 89% on room air. On physical examination, there is peripheral cyanosis with pallor, coldness of the extremities, diaphoresis, and marked peripheral veins distension. Lung auscultation reveals bilateral absence of the lung sounds over the lower lobes and widespread rales over the other lung fields. On cardiac auscultation, there is a protodiastolic gallop and S2 accentuation best heard in the second intercostal space at the left sternal border. Abdominal palpation shows signs of intraperitoneal fluid accumulation and hepatomegaly. Considering the low cardiac output, milrinone is administered as an inotropic agent. What is the most likely side effect which can result from administration of milrinone?
A. Asystole
B. Third grade AV-blockade
C. Ventricular arrhythmias (Correct Answer)
D. Supraventricular arrhythmia
E. QT-prolongation
Explanation: ***Ventricular arrhythmias***
- **Milrinone** is a positive inotropic agent and vasodilator used in severe heart failure; it **increases cardiac contractility** and **reduces afterload**.
- Its mechanism of action, phosphodiesterase (PDE-3) inhibition, can increase intracellular cAMP in cardiomyocytes, raising the risk of **ventricular arrhythmias**, particularly in patients with pre-existing heart conditions or electrolyte imbalances.
*Asystole*
- While milrinone can have significant cardiovascular effects, **asystole** (complete cessation of electrical and mechanical activity of the heart) is not a common or direct side effect.
- Asystole is typically associated with conditions like severe myocardial ischemia, advanced conduction system disease, or terminal stages of shock.
*Third grade AV-blockade*
- **Third-degree AV block** involves complete dissociation between atrial and ventricular electrical activity.
- Milrinone's primary action is to increase contractility and vasodilation; it does not directly interfere with the **AV node conduction** in a way that would commonly cause complete heart block.
*Supraventricular arrhythmia*
- While milrinone can cause various rhythm disturbances due to increased **cAMP levels** and myocardial excitability, **supraventricular arrhythmias** (like atrial fibrillation or flutter) are less commonly reported as a primary side effect compared to ventricular arrhythmias.
- The direct effect on ventricular excitability is more pronounced.
*QT-prolongation*
- **QT prolongation** can lead to torsades de pointes and other ventricular arrhythmias, but milrinone itself is not typically listed as a drug that directly causes significant QT prolongation.
- Medications that block **potassium channels** are more commonly associated with this side effect.
Question 363: A 61-year-old woman presents to the emergency room with left leg pain and swelling. She recently returned to the United States from a trip to India. Her past medical history is notable for osteoarthritis in both hips, lumbar spinal stenosis, and hypertension. She takes lisinopril. Her temperature is 99°F (37.2°C), blood pressure is 140/85 mmHg, pulse is 110/min, and respirations are 24/min. On examination, her left calf is larger than her right calf. A lower extremity ultrasound demonstrates a deep venous thrombosis in the left femoral vein. Results from a complete blood count are within normal limits. She is admitted and started on unfractionated heparin. Seven days later, she presents with a dark erythematous skin lesion on her left thigh and worsening left leg swelling. A lower extremity ultrasound demonstrates a persistent deep venous thrombosis in the left femoral vein as well as a new deep venous thrombosis in the left popliteal vein. Results of a complete blood count are shown below:
Hemoglobin: 13.1 g/dL
Hematocrit: 38%
Leukocyte count: 9,600/mm^3 with normal differential
Platelet count: 74,000/mm^3
A medication with which of the following mechanisms of action is most appropriate to initiate in this patient after stopping the heparin?
A. Cyclooxygenase inhibitor
B. Direct thrombin inhibitor (Correct Answer)
C. Anti-thrombin III activator
D. Adenosine-diphosphate (ADP) receptor antagonist
E. Vitamin K epoxide reductase inhibitor
Explanation: **Direct thrombin inhibitor**
- The patient's presentation with a new thrombus, despite being on heparin, and a significantly **decreased platelet count (74,000/mm^3)**, points toward **heparin-induced thrombocytopenia (HIT)**.
- In HIT, heparin must be stopped immediately, and a **non-heparin anticoagulant** like a **direct thrombin inhibitor (e.g., argatroban, bivalirudin)** is the appropriate next step to prevent further thrombosis while avoiding platelet activation.
*Cyclooxygenase inhibitor*
- **Cyclooxygenase inhibitors (e.g., NSAIDs, aspirin)** primarily inhibit platelet aggregation and inflammation but are not the primary treatment for active thrombosis or HIT.
- While effective in preventing arterial clots, they are **insufficient for treating established venous thrombosis**, especially in the context of HIT where platelet activation is a key pathological feature.
*Anti-thrombin III activator*
- **Heparin** itself works by activating antithrombin III, which is precisely the drug that caused the HIT in this patient.
- Administering another antithrombin III activator (e.g., antithrombin III concentrate) would not address the underlying **pathogenesis of HIT**, which involves heparin-dependent antibodies causing platelet activation and thrombosis.
*Adenosine-diphosphate (ADP) receptor antagonist*
- **ADP receptor antagonists (e.g., clopidogrel, ticagrelor)** inhibit platelet aggregation and are used in arterial thrombotic conditions like acute coronary syndrome or stroke prevention.
- While they inhibit platelets, they are **not the first-line treatment for HIT** and its associated venous thrombosis, which requires direct anticoagulation rather than solely antiplatelet therapy.
*Vitamin K epoxide reductase inhibitor*
- **Vitamin K epoxide reductase inhibitors (e.g., warfarin)** are effective oral anticoagulants that inhibit the synthesis of vitamin K-dependent clotting factors.
- However, starting warfarin in acute HIT is **contraindicated** initially because it can lead to a paradoxical prothrombotic state due to a rapid decrease in protein C levels, especially if started before the platelet count has recovered or without overlap with a rapidly acting anticoagulant.
Question 364: A 26-year-old woman is brought to the emergency department after a motor vehicle accident. She was driving on the highway when she was struck by a van. At the hospital she was conscious but was bleeding heavily from an open wound in her left leg. Pulse is 120/min and blood pressure is 96/68 mm Hg. She receives 3 L of intravenous saline and her pulse slowed to 80/min and blood pressure elevated to 116/70 mm Hg. The next morning she is found to have a hemoglobin of 6.2 g/dL. Her team decides to transfuse 1 unit of packed RBCs. Twenty minutes into the transfusion she develops a diffuse urticarial rash, wheezing, fever, and hypotension. The transfusion is immediately stopped and intramuscular epinephrine is administered. Which of the following scenarios is most consistent with this patient's reaction to the blood transfusion?
A. A patient history of cardiovascular disease
B. Unsanitary blood product storage practices in the hospital
C. A patient history of frequent sinopulmonary infections (Correct Answer)
D. Facial twitching when the patient's cheek is tapped
E. Prior transfusion reactions caused by the same donor
Explanation: ***A patient history of frequent sinopulmonary infections***
- The diffuse **urticarial rash, wheezing, fever, and hypotension** after a blood transfusion are classic signs of a **severe allergic reaction (anaphylaxis)**.
- Patients with a history of frequent sinopulmonary infections often have **IgA deficiency**, which can lead to the formation of anti-IgA antibodies. If transfused with blood containing IgA, these antibodies can trigger a severe anaphylactic reaction.
*A patient history of cardiovascular disease*
- While cardiovascular disease can influence how a patient tolerates a transfusion, it does not directly cause the specific constellation of symptoms like **urticaria, wheezing, and fever** that point to an allergic reaction.
- Cardiovascular issues might exacerbate circulatory collapse but wouldn't be the primary cause of an immediate, systemic allergic response.
*Unsanitary blood product storage practices in the hospital*
- Unsanitary storage practices are typically associated with **bacterial contamination** of blood products, leading to a **febrile non-hemolytic transfusion reaction** or **septic shock**, often with severe rigors and high fever.
- This scenario would not commonly present with prominent **urticaria and wheezing** as primary symptoms of an acute reaction.
*Facial twitching when the patient's cheek is tapped*
- Facial twitching when the cheek is tapped is known as **Chvostek's sign**, which is indicative of **hypocalcemia**.
- While rapid transfusion of large volumes of blood can sometimes lead to hypocalcemia due to citrate binding, the primary symptoms described (urticaria, wheezing, fever, hypotension) are not typical of hypocalcemia and point more strongly to an allergic reaction.
*Prior transfusion reactions caused by the same donor*
- While prior reactions to blood from the same donor could occur, it is highly unlikely in this scenario as blood components are typically sourced from various donors.
- The focus is on the patient's intrinsic predisposition (like IgA deficiency) rather than a specific donor incompatibility, especially since this is likely her first transfusion given the trauma.
Question 365: A 60-year-old woman presents to the emergency room with chest pain that started 20 minutes ago while watching television at home. The pain is substernal and squeezing in nature. She rates the pain as 6/10 and admits to having similar pain in the past with exertion. Her past medical history is significant for diabetes mellitus that is controlled with metformin. The physical examination is unremarkable. An electrocardiogram (ECG) shows ST-segment depression in the lateral leads. She is started on aspirin, nitroglycerin, metoprolol, unfractionated heparin, and insulin. She is asked not to take metformin while at the hospital. Three sets of cardiac enzymes are negative.
Lab results are given below:
Serum glucose 88 mg/dL
Sodium 142 mEq/L
Potassium 3.9 mEq/L
Chloride 101 mEq/L
Serum creatinine 1.2 mg/dL
Blood urea nitrogen 22 mg/dL
Cholesterol, total 170 mg/dL
HDL-cholesterol 40 mg/dL
LDL-cholesterol 80 mg/dL
Triglycerides 170 mg/dL
Hematocrit 38%
Hemoglobin 13 g/dL
Leucocyte count 7,500/mm3
Platelet count 185,000 /mm3
Activated partial thromboplastin time (aPTT) 30 seconds
Prothrombin time (PT) 12 seconds
Urinalysis
Glucose negative
Ketones negative
Leucocytes negative
Nitrites negative
Red blood cells (RBC) negative
Casts negative
An echocardiogram reveals left ventricular wall motion abnormalities. With the pain subsiding, she was admitted and the medications were continued. A coronary angiography is planned in 4 days. In addition to regular blood glucose testing, which of the following should be closely monitored in this patient?
A. Activated partial thromboplastin time (aPTT) alone
B. Prothrombin time alone
C. aPTT and platelet count (Correct Answer)
D. Platelet count alone
E. Prothrombin time and platelet count
Explanation: ***aPTT and platelet count***
- The patient is receiving **unfractionated heparin**, which requires monitoring of **aPTT** to ensure therapeutic anticoagulation and prevent bleeding complications.
- Heparin can also induce **heparin-induced thrombocytopenia (HIT)**, necessitating close monitoring of the **platelet count**.
*Activated partial thromboplastin time (aPTT) alone*
- While **aPTT** monitoring is crucial for unfractionated heparin, it does not account for the risk of **heparin-induced thrombocytopenia (HIT)**.
- Monitoring platelet count is equally important alongside aPTT in patients receiving heparin.
*Prothrombin time alone*
- **Prothrombin time (PT)** is used to monitor **warfarin** therapy, not unfractionated heparin.
- Monitoring PT in this context would be inappropriate and would not provide information about the efficacy or safety of the prescribed heparin.
*Platelet count alone*
- Monitoring **platelet count** is important for detecting **heparin-induced thrombocytopenia (HIT)**, but it does not assess the therapeutic effect of heparin.
- **aPTT** monitoring is essential to ensure adequate anticoagulation and prevent thrombotic events.
*Prothrombin time and platelet count*
- **Prothrombin time (PT)** is irrelevant for unfractionated heparin monitoring, as it measures the extrinsic pathway and is used for warfarin.
- Although **platelet count** monitoring is important, relying on PT is incorrect for unfractionated heparin management.
Question 366: A 2-year-old boy had increased bleeding during a circumcision. His birth and delivery were uncomplicated, and his mother had no issues with prolonged bleeding during labor. Of note, his maternal grandfather has a history of bleeding complications. The boy's vital signs are stable and physical examination is notable for scattered bruises on his lower extremities. The lab results are as follows:
Hemoglobin 12.8 gm %
Hematocrit 35.4%
WBC 8400/mm3
Platelets 215 x 109/L
PT 14 s
PTT 78 s
What is the most likely diagnosis?
A. Glanzmann thrombasthenia
B. Hemophilia A (Correct Answer)
C. Von Willebrand disease
D. Scurvy
E. Bernard-Soulier syndrome
Explanation: ***Hemophilia A***
- The patient's presentation with increased bleeding during circumcision, scattered bruises, and a **prolonged PTT** with normal PT and platelet count is highly suggestive of **Hemophilia A**.
- The familial history of bleeding complications in the maternal grandfather points towards an **X-linked recessive inheritance pattern**, characteristic of Hemophilia A.
- Hemophilia A results from **Factor VIII deficiency**, affecting the intrinsic coagulation pathway.
*Glanzmann thrombasthenia*
- This condition involves a defect in **platelet aggregation** due to deficiency of **GPIIb/IIIa**, which would typically manifest with a **normal platelet count** but abnormal platelet function tests.
- While it causes bruising and bleeding, it would not affect the PTT, as coagulation factors are normal in this platelet function disorder.
*Von Willebrand disease*
- This is the **most common inherited bleeding disorder** and typically presents with mucocutaneous bleeding and menorrhagia in females.
- While it can cause a **mildly prolonged PTT** due to low Factor VIII levels (vWF stabilizes Factor VIII), the PTT is typically only **mildly elevated**, not as significantly prolonged as seen here (78s vs normal ~25-35s).
- The **X-linked family history** (affected maternal grandfather, not parents) strongly favors hemophilia over the **autosomal dominant** inheritance of most vWD cases.
*Scurvy*
- Scurvy results from **vitamin C deficiency** leading to impaired collagen synthesis.
- While it can cause bleeding issues like petechiae and gingival bleeding, it would not cause a **prolonged PTT** or present with significant bleeding during a circumcision.
- Coagulation tests remain normal in scurvy.
*Bernard-Soulier syndrome*
- This is a rare, inherited platelet disorder characterized by **giant platelets** and **thrombocytopenia**, resulting from a defect in the **glycoprotein Ib/IX/V complex**.
- It would present with mucocutaneous bleeding and bruising, but the patient's **platelet count is normal** (215 × 10⁹/L) and the PTT would not be prolonged in this platelet function disorder.
Question 367: A 52-year-old woman is brought to the emergency department for a severe, sudden-onset headache, light-sensitivity, and neck stiffness that began 30 minutes ago. A CT scan of the head shows hyperdensity between the arachnoid mater and the pia mater. The patient undergoes an endovascular procedure. One week later, she falls as she is returning from the bathroom. Neurologic examination shows 3/5 strength in the right lower extremity and 5/5 in the left lower extremity. Treatment with which of the following drugs is most likely to have prevented the patient's current condition?
A. Fosphenytoin
B. Nitroglycerin
C. Enalapril
D. Fresh frozen plasma
E. Nimodipine (Correct Answer)
Explanation: ***Nimodipine***
- The patient experienced a **subarachnoid hemorrhage (SAH)**, indicated by the sudden-onset severe headache, neck stiffness, light sensitivity, and hyperdensity between the arachnoid and pia mater on CT scan.
- **Nimodipine**, a calcium channel blocker, is used to prevent **cerebral vasospasm** following SAH, which can lead to delayed cerebral ischemia and focal neurological deficits like the patient's new right lower extremity weakness.
*Fosphenytoin*
- **Fosphenytoin** is an **anticonvulsant** used to treat or prevent seizures.
- While seizures can occur after SAH, there is no mention of seizure activity in this patient, and fosphenytoin would not prevent **vasospasm-induced ischemia**.
*Nitroglycerin*
- **Nitroglycerin** is a potent **vasodilator** primarily used to treat angina and heart failure.
- It rapidly lowers blood pressure and would not be used to prevent cerebral vasospasm after SAH, and could potentially worsen cerebral perfusion if blood pressure drops too low.
*Enalapril*
- **Enalapril** is an **ACE inhibitor** used to treat hypertension and heart failure.
- It is a long-acting antihypertensive and is not indicated for the prevention of **cerebral vasospasm** after SAH.
*Fresh frozen plasma*
- **Fresh frozen plasma (FFP)** is used to replace clotting factors in patients with coagulopathies or significant bleeding.
- While SAH involves bleeding, FFP would be used to reverse anticoagulant effects or treat a severe clotting factor deficiency, not to prevent **delayed ischemic deficits** from vasospasm.
Question 368: A 57-year-old man with type 2 diabetes mellitus comes to the physician for a follow-up evaluation. He was recently diagnosed with hyperlipidemia, for which he takes several medications. His serum total cholesterol concentration is 295 mg/dL and serum high-density lipoprotein concentration is 19 mg/dL (N: > 40 mg/dL). The physician prescribes an additional drug that decreases hepatic production of triglycerides and reduces the release of VLDL and LDL through the inhibition of diacylglycerol acyltransferase 2. This patient should be advised to do which of the following?
A. This medication may cause gastrointestinal upset; take it with food.
B. Maintain a healthy diet and exercise regularly to maximize the drug's effect.
C. Pruritus is a common side effect that usually resolves spontaneously.
D. Report any signs of muscle pain or weakness immediately.
E. Monitor liver function tests regularly while taking this medication. (Correct Answer)
Explanation: ***Monitor liver function tests regularly while taking this medication.***
- The drug described inhibits **diacylglycerol acyltransferase 2 (DGAT2)**, an enzyme that catalyzes the final step in **triglyceride synthesis** in the liver, thereby reducing **VLDL** and **LDL** production and release.
- Drugs targeting hepatic lipid synthesis pathways, including DGAT2 inhibitors and related agents like **lomitapide** (an MTP inhibitor with similar effects on VLDL/LDL), carry a **BLACK BOX WARNING** for **hepatotoxicity**, including risk of hepatic steatosis, elevated transaminases, and potential liver failure.
- Regular monitoring of **liver function tests (AST, ALT, alkaline phosphatase, total bilirubin)** is **mandatory** - typically before treatment, then monthly for the first year, and regularly thereafter to detect drug-induced liver injury early.
*This medication may cause gastrointestinal upset; take it with food.*
- While **gastrointestinal side effects** (diarrhea, nausea, dyspepsia) can occur with lipid-lowering agents affecting hepatic metabolism, this is not the most critical safety concern for drugs inhibiting triglyceride synthesis.
- The primary and most serious risk is **hepatotoxicity**, making LFT monitoring the essential patient counseling point rather than routine GI symptom management.
*Maintain a healthy diet and exercise regularly to maximize the drug's effect.*
- **Lifestyle modifications** including diet (especially low-fat diet to reduce GI side effects and hepatic fat accumulation) and exercise are important adjuncts to all lipid-lowering therapy.
- However, this is general health advice rather than a specific safety monitoring requirement related to the drug's mechanism of action and serious adverse effect profile (hepatotoxicity).
*Pruritus is a common side effect that usually resolves spontaneously.*
- **Pruritus** (itching) and flushing are characteristic side effects of **niacin** (nicotinic acid) due to prostaglandin-mediated cutaneous vasodilation, often prevented with aspirin pretreatment.
- This is not a typical or prominent side effect of drugs targeting **DGAT2** or hepatic triglyceride synthesis pathways; the defining concern remains hepatotoxicity.
*Report any signs of muscle pain or weakness immediately.*
- **Myalgia**, **myopathy**, and **rhabdomyolysis** are well-recognized adverse effects of **statins** (HMG-CoA reductase inhibitors) due to effects on the mevalonate pathway and coenzyme Q10 depletion.
- The mechanism described (inhibiting **DGAT2** and triglyceride synthesis) does not directly affect muscle metabolism or create significant risk for myopathy, making liver monitoring the appropriate priority for this specific drug class.
Question 369: A 20-year-old man presents to his primary care provider with a history of recurrent cough, wheezing, and breathlessness since early childhood. He was previously diagnosed with allergic rhinitis and bronchial asthma. For his allergic rhinitis, he uses intranasal fluticasone. For his asthma, he uses an albuterol inhaler as a rescue inhaler. It is decided to initiate a new medication for daily use. Which of the following medications, with its corresponding mechanism, is the next best step in therapy?
A. Omalizumab acts by blocking both circulating and mast cell-bound IgE.
B. Theophylline works through phosphodiesterase inhibition and has anti-inflammatory effects.
C. Antileukotrienes (such as montelukast and zafirlukast) exert their beneficial effects in bronchial asthma by blocking CysLT1-receptors.
D. β2-agonists reverse bronchoconstriction but do not control the underlying inflammation.
E. Inhaled corticosteroids reduce inflammation by inhibiting the production of inflammatory mediators. (Correct Answer)
Explanation: ***Inhaled corticosteroids reduce inflammation by inhibiting the production of inflammatory mediators.***
* **Inhaled corticosteroids (ICS)** are the cornerstone of **long-term control therapy** for persistent asthma, as they effectively reduce airway inflammation.
* Given the patient's history of recurrent symptoms and allergic rhinitis, suggesting a significant inflammatory component, **daily ICS** would be the most appropriate "next best step" for asthma management.
*Omalizumab acts by blocking both circulating and mast cell-bound IgE.*
* **Omalizumab** is an **anti-IgE antibody** used for severe persistent allergic asthma that is not well-controlled with high-dose ICS and other controllers.
* It is typically considered for more severe cases and not as an initial "next best step" for daily use in a patient who is only on a rescue inhaler.
*Theophylline works through phosphodiesterase inhibition and has anti-inflammatory effects.*
* **Theophylline** is a **bronchodilator** with mild anti-inflammatory effects, but its use is limited by its narrow therapeutic window and potential for significant side effects like **arrhythmias** and **seizures**.
* It is generally reserved for patients whose asthma is not well-controlled with ICS and long-acting beta-agonists (LABAs) due to its less favorable side effect profile compared to ICS.
*Antileukotrienes (such as montelukast and zafirlukast) exert their beneficial effects in bronchial asthma by blocking CysLT1-receptors.*
* **Antileukotrienes** are effective in asthma management, particularly for **aspirin-exacerbated respiratory disease** and **exercise-induced bronchoconstriction**, and have some anti-inflammatory properties.
* While they can be used as an alternative or add-on therapy, **inhaled corticosteroids** are generally more potent anti-inflammatory agents and are considered first-line for daily control of persistent asthma.
*β2-agonists reverse bronchoconstriction but do not control the underlying inflammation.*
* **Short-acting beta2-agonists (SABAs)** like albuterol are primarily **rescue medications** that provide rapid relief from bronchoconstriction but do not address the underlying airway inflammation in asthma.
* The question states the patient is already using an albuterol inhaler as a rescue and needs a new medication for "daily use," indicating a need for controller therapy, not another reliever.
Question 370: Two weeks after being hospitalized for acute pancreatitis, a 36-year-old man comes to the physician for a follow-up examination. Multiple family members have coronary artery disease. Physical examination shows multiple, yellow papular lesions on both upper eyelids. Fasting serum lipid studies show:
Total cholesterol 280 mg/dl
HDL-cholesterol 40 mg/dl
LDL-cholesterol 185 mg/dl
Triglycerides 1080 mg/dl
Treatment with gemfibrozil is initiated. The expected beneficial effect of this drug is most likely due to which of the following mechanisms of action?
A. Formation of bile acid complex
B. Upregulation of lipoprotein lipase
C. Inhibition of intestinal cholesterol absorption
D. Inhibition of HMG-CoA reductase
E. Activation of peroxisome proliferator-activated receptors (Correct Answer)
Explanation: ***Activation of peroxisome proliferator-activated receptors***
- **Gemfibrozil** is a **fibrate drug** that acts by activating **peroxisome proliferator-activated receptor alpha (PPAR-α)**.
- Activation of **PPAR-α** leads to increased **lipoprotein lipase (LPL) activity**, enhanced fatty acid oxidation, and reduced hepatic VLDL production, ultimately lowering **triglycerides** and increasing **HDL-cholesterol**.
*Formation of bile acid complex*
- This mechanism of action is characteristic of **bile acid sequestrants** (e.g., cholestyramine, colesevelam), which bind to bile acids in the intestine, preventing their reabsorption.
- Bile acid sequestrants primarily lower **LDL-cholesterol** and are not the primary mechanism of action for fibrates.
*Upregulation of lipoprotein lipase*
- While fibrates do lead to increased **lipoprotein lipase activity**, this is a *downstream effect* of their primary mechanism, which is the **activation of PPAR-α**.
- Without the activation of PPAR-α, the upregulation of lipoprotein lipase would not occur.
*Inhibition of intestinal cholesterol absorption*
- This mechanism is characteristic of **cholesterol absorption inhibitors** such as **ezetimibe**, which specifically block the **Niemann-Pick C1-Like 1 (NPC1L1) protein** on enterocytes.
- This mechanism is not associated with the action of fibrate drugs like gemfibrozil.
*Inhibition of HMG-CoA reductase*
- This is the primary mechanism of action for **statins** (e.g., atorvastatin, simvastatin), which inhibit the rate-limiting enzyme in **cholesterol biosynthesis** in the liver.
- Statins are mainly used to lower **LDL-cholesterol**, whereas fibrates like gemfibrozil are primarily used for hypertriglyceridemia.
