A 27-year-old man presents to the outpatient clinic with a swollen and painful toe. The pain intensity increased further after he went to a party last night. Which of the following is the drug of choice for the treatment of this patient's condition?
Q702
A 43-year-old man presents to the emergency department with nausea and vomiting. He says symptoms onset 4 hours ago and is progressively worsening. He denies any hematemesis. Past medical history is significant for a recent negative screening colonoscopy that was performed due to a family history of colon cancer. His vital signs are significant for a temperature of 39.5°C (103.1°F). Physical examination is unremarkable. A contrast CT of the abdomen reveals a colonic perforation. Laboratory findings are significant for an elevated WBC count with a predominant left shift, a decreased platelet count, increased PT and PTT, slightly decreased hemoglobin/hematocrit, and prolonged bleeding time. Which of the following is most closely related to this patient's prolonged PT and PTT?
Q703
A 37-year-old previously healthy woman presents to the emergency room with right leg pain and difficulty breathing. She recently returned from a trip to Alaska and noticed her leg started to swell when she got home. Her medications include a multivitamin and oral contraceptives. She is diagnosed with a deep venous thrombosis complicated by a pulmonary embolism and started on anticoagulation. She remains stable and is discharged on the third hospital day with long-term anticoagulation. During the 2 month follow-up visit, the patient's lab results are as follows:
Hemoglobin: 14 g/dL
Hematocrit: 44%
Leukocyte count: 5,000/mm^3 with normal differential
Platelet count: 300,000/mm^3
Prothrombin time: 23 seconds
Partial thromboplastin time (activated): 20 seconds
Bleeding time: 4 minutes
Which of the following factors is initially inhibited in the target pathway for her long-term treatment?
Q704
A 50-year-old woman, gravida 5, para 5, comes to the physician for the evaluation of decreased sexual desire for approximately 6 months. She has been sexually active with her husband but reports that she has no desire in having sexual intercourse anymore. She states that she feels guilty and is worried about losing her husband if this problem goes on for a longer period of time. She also reports that they have had several fights recently due to financial problems. She has problems going to sleep and wakes up often, and is tired throughout the day. One year ago, the patient underwent hysterectomy with bilateral salpingo-oophorectomy due to uterine prolapse. Her last menstrual period was 2 years ago. She does not smoke. She drinks 3–4 glasses of wine daily. Vital signs are within normal limits. Physical examination shows no abnormalities except for an enlarged liver. Which of the following most likely explains this patient's loss of libido?
Q705
A 73-year-old woman presents to the emergency department with diffuse abdominal pain, nausea, and vomiting. Her daughter who accompanies her says she was in her usual state of health until two days ago when she started to complain of abdominal pain and was unable to tolerate oral intake. She has hypertension, congestive heart failure, atrial fibrillation, and osteoarthritis. She underwent an exploratory laparotomy for an ovarian mass a year ago where a mucinous cystadenoma was excised. Her medications include aspirin, nifedipine, lisinopril, metoprolol, warfarin, and Tylenol as needed for pain. She does not drink alcohol or smoke cigarettes. She appears ill and disoriented. Her temperature is 37.9°C (100.3°F), blood pressure is 102/60 mm Hg, pulse is 110/min and irregular, and respirations are 16/min. Examination shows diffuse tenderness to palpation of the abdomen. The abdomen is tympanitic on percussion. Bowel sounds are hyperactive. The lungs are clear to auscultation bilaterally. There is a soft crescendo-decrescendo murmur best auscultated in the right second intercostal space. Laboratory studies show:
Hemoglobin 10.2 g/dL
Leukocyte count 14,000/mm3
Platelet count 130,000/mm3
Prothrombin time 38 seconds
INR 3.2
Serum
Na+ 132 mEq/dL
K+ 3.6 mEq/dL
Cl- 102 mEq/dL
HCO3- 19 mEq/dL
Urea nitrogen 36 mg/dl
Creatinine 2.3 mg/dL
Lactate 2.8 mEq/dL (N= 0.5-2.2 mEq/dL)
An x-ray of the abdomen shows multiple centrally located dilated loops of gas filled bowel. There is no free air under the diaphragm. A nasogastric tube is inserted and IV fluids and empiric antibiotic therapy are started. Emergent exploratory laparotomy is planned. Which of the following is the next best step in management?
Q706
A 60-year-old man is brought to the emergency room because of fever and increasing confusion for the past 2 days. He has paranoid schizophrenia treated with chlorpromazine. He appears diaphoretic. His temperature is 40°C (104°F), pulse is 130/min, respirations are 29/min, and blood pressure is 155/100 mm Hg. Neurologic examination shows psychomotor agitation and incoherent speech. There is generalized muscle rigidity. His deep tendon reflexes are decreased bilaterally. Serum laboratory analysis shows a leukocyte count of 11,300/mm3 and serum creatine kinase concentration of 833 U/L. The most appropriate drug for this patient acts by inhibiting which of the following?
Q707
A 49-year-old man comes to the physician because of a 5-month history of progressive fatigue and exertional dyspnea. Cardiac examination shows a loud S2 in the 2nd left intercostal space. Right heart catheterization shows a pulmonary artery pressure of 32 mm Hg. Treatment with bosentan is initiated. The beneficial effect of this drug is due to binding to which of the following?
Q708
A 69-year-old woman with type 2 diabetes mellitus has an HbA1c of 7.9% and has been using basal-bolus insulin to manage her diabetes for the past 5 years. She has been maintaining a healthy diet, taking her insulin as scheduled but her records show morning hyperglycemia before eating breakfast. To determine the cause of this hyperglycemia, you ask her to set an alarm and take her blood glucose at 3 am. At 3 am her blood glucose is 49 mg/dL. Which of the following statements best describes the management of this patient's current condition?
Q709
A 44-year-old woman is admitted after an episode of dizziness and palpitations with a subsequent loss of consciousness. At the time of admission, the patient is alert, but then quickly becomes lethargic and reports reoccurrence of palpitations. Past medical history is significant for an episode of ventricular tachycardia 4 months ago, now managed with pharmacologic antiarrhythmic prophylaxis. An ECG is obtained and is shown on the image. Which of the following antiarrhythmic drugs is most likely responsible for this patient's condition?
Q710
A 48-year-old homeless man is brought to the emergency department 2 hours after his right arm was burned by a fire. He is diagnosed with extensive third-degree burns of the right forearm and upper arm and is admitted to the hospital for debridement and grafting. During his stay in the hospital, he suddenly develops confusion and agitation. Neurologic examination shows horizontal nystagmus and a broad-based gait. Laboratory studies show decreased erythrocyte transketolase activity. Administration of which of the following most likely caused this patient's current condition?
Autonomic/CV Drugs US Medical PG Practice Questions and MCQs
Question 701: A 27-year-old man presents to the outpatient clinic with a swollen and painful toe. The pain intensity increased further after he went to a party last night. Which of the following is the drug of choice for the treatment of this patient's condition?
A. Aspirin
B. Rasburicase
C. Indomethacin (Correct Answer)
D. Probenecid
E. Allopurinol
Explanation: ***Indomethacin***
- This patient's presentation with a **swollen and painful toe** (likely the first metatarsophalangeal joint) after a party is highly suggestive of **acute gout**, an inflammatory arthritis caused by **monosodium urate crystal deposition**.
- **Indomethacin** is a potent **NSAID** traditionally considered the "classic" treatment for acute gout flares, though **current guidelines recommend any NSAID at anti-inflammatory doses** (indomethacin, naproxen, ibuprofen) as equally effective first-line options.
- Other first-line options include **colchicine** and **corticosteroids** when NSAIDs are contraindicated.
*Aspirin*
- While aspirin is an NSAID, **low-dose aspirin** (<2 g/day) can actually **decrease renal uric acid excretion**, potentially worsening hyperuricemia and gout.
- At high doses (>3 g/day), aspirin has uricosuric effects, but it is generally **avoided in acute gout** due to unpredictable effects on uric acid levels.
*Rasburicase*
- This is a **recombinant urate oxidase** enzyme that rapidly converts uric acid to allantoin, primarily used for **tumor lysis syndrome** with severe hyperuricemia in oncology patients.
- It is **not used for acute gout** in otherwise healthy individuals and is administered intravenously in hospital settings.
*Probenecid*
- **Probenecid** is a **uricosuric agent** that increases renal uric acid excretion by blocking the URAT1 transporter in the proximal tubule, used for **chronic management** of gout.
- It is **contraindicated during acute attacks** as it can mobilize urate deposits and worsen the flare; initiation should occur after the acute episode has resolved.
*Allopurinol*
- **Allopurinol** is a **xanthine oxidase inhibitor** that reduces uric acid production and is the most common agent for **long-term prophylaxis** of recurrent gout.
- It should **not be initiated during an acute attack** as sudden changes in serum uric acid can precipitate or prolong the flare; if already taking allopurinol, continue it during acute attacks.
Question 702: A 43-year-old man presents to the emergency department with nausea and vomiting. He says symptoms onset 4 hours ago and is progressively worsening. He denies any hematemesis. Past medical history is significant for a recent negative screening colonoscopy that was performed due to a family history of colon cancer. His vital signs are significant for a temperature of 39.5°C (103.1°F). Physical examination is unremarkable. A contrast CT of the abdomen reveals a colonic perforation. Laboratory findings are significant for an elevated WBC count with a predominant left shift, a decreased platelet count, increased PT and PTT, slightly decreased hemoglobin/hematocrit, and prolonged bleeding time. Which of the following is most closely related to this patient's prolonged PT and PTT?
A. Vitamin K
B. Giant platelets
C. COX-1 and COX-2
D. GpIIb/IIIa
E. Fibrinogen (Correct Answer)
Explanation: ***Fibrinogen***
- This patient has **disseminated intravascular coagulation (DIC)** secondary to sepsis from colonic perforation, evidenced by **elevated PT/PTT**, **thrombocytopenia**, **prolonged bleeding time**, and **decreased hemoglobin**
- In DIC, there is widespread activation of coagulation leading to **consumption of clotting factors**, particularly **fibrinogen (Factor I)**, which is the substrate for fibrin clot formation in the **common pathway**
- **Low fibrinogen directly prolongs PT, PTT, and thrombin time** because fibrinogen is essential for the final step of clot formation measured by these tests
- Fibrinogen consumption is a hallmark of DIC and directly explains the coagulation factor deficiency causing PT/PTT prolongation
*Vitamin K*
- Vitamin K deficiency causes deficiency of factors II, VII, IX, and X, leading to prolonged PT and PTT
- However, the acute presentation with **sepsis**, **thrombocytopenia**, and **prolonged bleeding time** indicates **DIC with factor consumption**, not vitamin K deficiency
- Vitamin K deficiency would not explain the low platelet count or the acute septic picture
*Giant platelets*
- Giant platelets (megathrombocytes) indicate **increased platelet turnover** and bone marrow attempting to compensate for peripheral platelet destruction in DIC
- While they explain the **thrombocytopenia** and contribute to **prolonged bleeding time**, they **do not prolong PT or PTT**
- **PT and PTT measure coagulation factors in platelet-poor plasma**, not platelet function
*COX-1 and COX-2*
- COX-1 inhibitors (aspirin) block thromboxane A2, impairing platelet aggregation and prolonging **bleeding time** but not PT/PTT
- COX-2 inhibitors primarily reduce inflammation with minimal platelet effects
- Neither directly affect the coagulation cascade factors measured by PT/PTT
*GpIIb/IIIa*
- Glycoprotein IIb/IIIa receptor inhibitors (abciximab, eptifibatide, tirofiban) prevent platelet aggregation
- They prolong **bleeding time** and can cause thrombocytopenia, but **do not prolong PT or PTT**
- PT/PTT measure coagulation factors, not platelet function
Question 703: A 37-year-old previously healthy woman presents to the emergency room with right leg pain and difficulty breathing. She recently returned from a trip to Alaska and noticed her leg started to swell when she got home. Her medications include a multivitamin and oral contraceptives. She is diagnosed with a deep venous thrombosis complicated by a pulmonary embolism and started on anticoagulation. She remains stable and is discharged on the third hospital day with long-term anticoagulation. During the 2 month follow-up visit, the patient's lab results are as follows:
Hemoglobin: 14 g/dL
Hematocrit: 44%
Leukocyte count: 5,000/mm^3 with normal differential
Platelet count: 300,000/mm^3
Prothrombin time: 23 seconds
Partial thromboplastin time (activated): 20 seconds
Bleeding time: 4 minutes
Which of the following factors is initially inhibited in the target pathway for her long-term treatment?
A. VII (Correct Answer)
B. IX
C. V
D. X
E. II
Explanation: ***VII***
- The patient is taking long-term anticoagulation, specifically noted by the **prolonged prothrombin time (PT)** of 23 seconds (normal 11-13.5 seconds) while the **aPTT is shortened** (normal 25-35 seconds), indicating the target pathway is the **extrinsic pathway** of coagulation.
- **Warfarin**, a common long-term oral anticoagulant, targets **Vitamin K-dependent factors** (II, VII, IX, X), and Factor VII has the **shortest half-life**, leading to its inhibition (and prolongation of PT) earliest.
*IX*
- **Factor IX** is part of the **intrinsic pathway** and is also a Vitamin K-dependent factor, but its inhibition would primarily prolong the **aPTT**, which is shortened in this case.
- While warfarin eventually inhibits Factor IX, Factor VII inhibition and PT prolongation occur more rapidly.
*V*
- **Factor V** is a non-Vitamin K-dependent factor involved in both the intrinsic and common pathways; its inhibition is not the primary mechanism of action for common long-term oral anticoagulants like warfarin.
- Inhibition of Factor V would likely affect both PT and aPTT, not selectively prolonging PT as seen here.
*X*
- **Factor X** is a Vitamin K-dependent factor in the **common pathway**, and its inhibition would prolong both PT and aPTT.
- While warfarin inhibits Factor X, Factor VII has a shorter half-life and its inhibition is primarily responsible for the initial prolongation of PT.
*II*
- **Factor II (prothrombin)** is a **Vitamin K-dependent factor** in the **common pathway**, and its inhibition would prolong both PT and aPTT.
- It has a longer half-life than Factor VII, so Factor VII's inhibition and PT prolongation would be seen first with warfarin therapy.
Question 704: A 50-year-old woman, gravida 5, para 5, comes to the physician for the evaluation of decreased sexual desire for approximately 6 months. She has been sexually active with her husband but reports that she has no desire in having sexual intercourse anymore. She states that she feels guilty and is worried about losing her husband if this problem goes on for a longer period of time. She also reports that they have had several fights recently due to financial problems. She has problems going to sleep and wakes up often, and is tired throughout the day. One year ago, the patient underwent hysterectomy with bilateral salpingo-oophorectomy due to uterine prolapse. Her last menstrual period was 2 years ago. She does not smoke. She drinks 3–4 glasses of wine daily. Vital signs are within normal limits. Physical examination shows no abnormalities except for an enlarged liver. Which of the following most likely explains this patient's loss of libido?
A. Chronic alcohol intake (Correct Answer)
B. Stress
C. Decreased testosterone
D. Major depressive disorder
E. Elevated prolactin
Explanation: ***Chronic alcohol intake***
- The patient consumes **3-4 glasses of wine daily**, which is considered heavy drinking for women and can significantly **reduce libido** and cause hepatic dysfunction.
- The presence of an **enlarged liver on physical exam** further supports chronic alcohol use as a likely cause for her symptoms, including decreased sexual desire.
*Stress*
- While the patient is experiencing stress due to financial problems and marital issues, **stress** alone is less likely to cause a **physical finding like an enlarged liver**.
- Although stress can contribute to decreased libido, it does not fully explain the entire clinical picture observed.
*Decreased testosterone*
- The patient's hysterectomy with bilateral salpingo-oophorectomy 1 year prior would lead to a **decrease in ovarian hormone production**, including testosterone.
- However, while **decreased testosterone** can cause low libido, this explanation does not account for the **enlarged liver**, which points more strongly towards chronic alcohol consumption.
*Major depressive disorder*
- Symptoms like **decreased sleep**, feeling tired, guilt, and reduced sexual desire are consistent with **major depressive disorder**.
- However, an **enlarged liver** is not a typical symptom of major depressive disorder, making chronic alcohol intake a more unifying diagnosis for the presented symptoms.
*Elevated prolactin*
- **Elevated prolactin** can cause decreased libido, amenorrhea (which is not relevant here as she had a hysterectomy), and sometimes galactorrhea.
- However, there is **no direct evidence or symptoms** presented to suggest elevated prolactin, and it would not explain the enlarged liver.
Question 705: A 73-year-old woman presents to the emergency department with diffuse abdominal pain, nausea, and vomiting. Her daughter who accompanies her says she was in her usual state of health until two days ago when she started to complain of abdominal pain and was unable to tolerate oral intake. She has hypertension, congestive heart failure, atrial fibrillation, and osteoarthritis. She underwent an exploratory laparotomy for an ovarian mass a year ago where a mucinous cystadenoma was excised. Her medications include aspirin, nifedipine, lisinopril, metoprolol, warfarin, and Tylenol as needed for pain. She does not drink alcohol or smoke cigarettes. She appears ill and disoriented. Her temperature is 37.9°C (100.3°F), blood pressure is 102/60 mm Hg, pulse is 110/min and irregular, and respirations are 16/min. Examination shows diffuse tenderness to palpation of the abdomen. The abdomen is tympanitic on percussion. Bowel sounds are hyperactive. The lungs are clear to auscultation bilaterally. There is a soft crescendo-decrescendo murmur best auscultated in the right second intercostal space. Laboratory studies show:
Hemoglobin 10.2 g/dL
Leukocyte count 14,000/mm3
Platelet count 130,000/mm3
Prothrombin time 38 seconds
INR 3.2
Serum
Na+ 132 mEq/dL
K+ 3.6 mEq/dL
Cl- 102 mEq/dL
HCO3- 19 mEq/dL
Urea nitrogen 36 mg/dl
Creatinine 2.3 mg/dL
Lactate 2.8 mEq/dL (N= 0.5-2.2 mEq/dL)
An x-ray of the abdomen shows multiple centrally located dilated loops of gas filled bowel. There is no free air under the diaphragm. A nasogastric tube is inserted and IV fluids and empiric antibiotic therapy are started. Emergent exploratory laparotomy is planned. Which of the following is the next best step in management?
A. Administer unfractionated heparin
B. Administer protamine sulfate
C. Administer recombinant activated factor VII
D. Administer platelet concentrate
E. Administer fresh frozen plasma and Vitamin K (Correct Answer)
Explanation: ***Administer fresh frozen plasma and Vitamin K***
- This patient presents with suspected **bowel ischemia** requiring emergent surgery, exacerbated by an **elevated INR (3.2)** due to warfarin use. **Fresh frozen plasma (FFP)** provides immediate replacement of clotting factors, while **Vitamin K** helps to restore endogenous factor synthesis over a longer period.
- Reversing the anticoagulation rapidly is crucial to minimize the risk of severe **intraoperative and postoperative bleeding**, which would complicate an already critical condition.
*Administer unfractionated heparin*
- **Unfractionated heparin** is an anticoagulant and would worsen the patient's bleeding risk, making emergent surgery extremely dangerous.
- It would further increase the risk of hemorrhage in a patient already coagulopathic from warfarin.
*Administer protamine sulfate*
- **Protamine sulfate** is used to reverse the effects of **heparin**, not warfarin.
- Administering protamine would have no effect on the **INR elevation** caused by warfarin and would not correct the patient's coagulopathy.
*Administer recombinant activated factor VII*
- **Recombinant activated factor VII (rFVIIa)** is a potent procoagulant, but its use is typically reserved for severe, life-threatening bleeding not responsive to conventional therapy in patients with specific coagulation factor deficiencies.
- While it can help improve coagulation, it carries a significant risk of **thromboembolic events**, which could be particularly dangerous in this patient with a history of **atrial fibrillation** and suspected ischemia, and it is not the first-line treatment for warfarin reversal.
*Administer platelet concentrate*
- The patient's **platelet count (130,000/mm3)** is within the acceptable range for most surgeries and her coagulopathy is primarily due to **warfarin-induced factor deficiencies (elevated INR)**.
- Administering platelet concentrate would not address the underlying **coagulopathy** caused by warfarin and would be unnecessary in this situation.
Question 706: A 60-year-old man is brought to the emergency room because of fever and increasing confusion for the past 2 days. He has paranoid schizophrenia treated with chlorpromazine. He appears diaphoretic. His temperature is 40°C (104°F), pulse is 130/min, respirations are 29/min, and blood pressure is 155/100 mm Hg. Neurologic examination shows psychomotor agitation and incoherent speech. There is generalized muscle rigidity. His deep tendon reflexes are decreased bilaterally. Serum laboratory analysis shows a leukocyte count of 11,300/mm3 and serum creatine kinase concentration of 833 U/L. The most appropriate drug for this patient acts by inhibiting which of the following?
A. Ryanodine receptor on the sarcoplasmic reticulum (Correct Answer)
B. Cholinesterase
C. Postsynaptic dopamine D2 receptors and serotonin 2A receptors
D. Beta adrenergic receptors
E. Histamine H1 receptor and serotonin 2 receptors
Explanation: ***Ryanodine receptor on the sarcoplasmic reticulum***
- The patient exhibits symptoms of **neuroleptic malignant syndrome (NMS)**, characterized by fever, muscle rigidity, altered mental status, and autonomic instability, likely induced by **chlorpromazine** (an antipsychotic).
- The most appropriate treatment for NMS is often **dantrolene**, which acts by inhibiting the **ryanodine receptor** on the sarcoplasmic reticulum, thereby reducing intracellular calcium release and muscle contraction.
*Cholinesterase*
- Inhibiting cholinesterase would lead to increased acetylcholine, which is the treatment strategy for conditions like **myasthenia gravis** or **Alzheimer's disease**.
- This mechanism is not relevant for treating NMS, which involves dopaminergic blockade and muscle rigidity.
*Postsynaptic dopamine D2 receptors and serotonin 2A receptors*
- **Chlorpromazine**, the causative agent for NMS in this patient, is a dopamine D2 receptor antagonist (and to a lesser extent, a serotonin 2A receptor antagonist).
- Further inhibition of these receptors would worsen, not improve, NMS symptoms.
*Beta adrenergic receptors*
- **Beta-blockers** are used to treat conditions like hypertension, angina, and anxiety by reducing sympathetic nervous system activity.
- While the patient has **tachycardia** and **hypertension**, these are symptoms of NMS, and beta-blockers would not address the underlying pathophysiology of muscle rigidity and hyperthermia.
*Histamine H1 receptor and serotonin 2 receptors*
- Antagonist effects on histamine H1 and serotonin 2 receptors are common side effects of many antipsychotics.
- While antihistamine effects can cause sedation, targeting these receptors would not resolve the critical features of NMS such as profound muscle rigidity and hyperthermia.
Question 707: A 49-year-old man comes to the physician because of a 5-month history of progressive fatigue and exertional dyspnea. Cardiac examination shows a loud S2 in the 2nd left intercostal space. Right heart catheterization shows a pulmonary artery pressure of 32 mm Hg. Treatment with bosentan is initiated. The beneficial effect of this drug is due to binding to which of the following?
A. L-type voltage-gated calcium channels
B. Adenosine receptors
C. Prostacyclin receptor
D. Phosphodiesterase-5
E. Endothelin receptors (Correct Answer)
Explanation: ***Endothelin receptors***
- **Bosentan** is an **endothelin receptor antagonist** that blocks the binding of **endothelin-1** to ETA and ETB receptors.
- This action leads to **vasodilation** in pulmonary arteries, reducing pulmonary vascular resistance and benefiting patients with pulmonary hypertension.
*L-type voltage-gated calcium channels*
- These channels are blocked by **calcium channel blockers** such as amlodipine or diltiazem, which are not bosentan.
- While some calcium channel blockers can be used in specific subgroups of pulmonary hypertension, their mechanism of action is distinct from bosentan.
*Adenosine receptors*
- **Adenosine receptor agonists** like adenosine itself cause vasodilation, particularly in the coronary circulation, and are used diagnostically for stress testing.
- Bosentan does not act on adenosine receptors; its mechanism is focused on the endothelin pathway.
*Prostacyclin receptor*
- **Prostacyclin analogs** (e.g., epoprostenol, treprostinil) act on prostacyclin receptors, stimulating adenylate cyclase to increase cAMP and cause vasodilation.
- Bosentan's mechanism is entirely separate from the prostacyclin pathway.
*Phosphodiesterase-5*
- **Phosphodiesterase-5 (PDE5) inhibitors** (e.g., sildenafil, tadalafil) increase cGMP levels, leading to vasodilation.
- This is a common treatment for pulmonary hypertension, but bosentan belongs to a different class of drugs.
Question 708: A 69-year-old woman with type 2 diabetes mellitus has an HbA1c of 7.9% and has been using basal-bolus insulin to manage her diabetes for the past 5 years. She has been maintaining a healthy diet, taking her insulin as scheduled but her records show morning hyperglycemia before eating breakfast. To determine the cause of this hyperglycemia, you ask her to set an alarm and take her blood glucose at 3 am. At 3 am her blood glucose is 49 mg/dL. Which of the following statements best describes the management of this patient's current condition?
A. She is experiencing Somogyi effect so her nighttime insulin should be increased
B. She is experiencing dawn phenomenon so her nighttime insulin should be decreased
C. Hyperosmolar hyperglycemic state; increase nighttime insulin
D. She is experiencing Somogyi effect so her nighttime insulin should be decreased (Correct Answer)
E. She is experiencing dawn phenomenon so her nighttime insulin should be kept the same
Explanation: ***She is experiencing Somogyi effect so her nighttime insulin should be decreased***
- The **Somogyi effect** (rebound hyperglycemia) occurs when a drop in blood glucose during the night (49 mg/dL at 3 am indicates **hypoglycemia**) triggers a release of counter-regulatory hormones, leading to **hyperglycemia** in the morning.
- To prevent nocturnal hypoglycemia and subsequent rebound hyperglycemia, the **nighttime insulin dose should be decreased**.
*She is experiencing Somogyi effect so her nighttime insulin should be increased*
- While the patient is experiencing the **Somogyi effect**, increasing nighttime insulin would worsen the nocturnal hypoglycemia, further exacerbating the rebound hyperglycemia.
- The core issue is **nocturnal hypoglycemia**, which is addressed by reducing, not increasing, the insulin dose.
*She is experiencing dawn phenomenon so her nighttime insulin should be decreased*
- The **dawn phenomenon** involves a natural rise in blood glucose in the early morning due to hormonal surges, without preceding hypoglycemia, and would typically necessitate an *increase* in nighttime insulin.
- Since the patient exhibited **hypoglycemia at 3 am**, the dawn phenomenon is not the cause of her morning hyperglycemia.
*Hyperosmolar hyperglycemic state; increase nighttime insulin*
- **Hyperosmolar hyperglycemic state (HHS)** is a severe complication characterized by extreme hyperglycemia, dehydration, and altered consciousness, usually in type 2 diabetes with very high glucose levels (>600 mg/dL), which is not indicated by the HbA1c or 3 am glucose reading.
- Increasing insulin might be part of acute HHS management, but it's not the underlying condition or appropriate treatment for this specific presentation of overnight hypoglycemia followed by morning hyperglycemia.
*She is experiencing dawn phenomenon so her nighttime insulin should be kept the same*
- If it were the **dawn phenomenon**, the 3 am blood glucose would likely be normal or slightly elevated, not hypoglycemic.
- Keeping the insulin dose the same would not address the underlying nocturnal hypoglycemia, nor the subsequent morning hyperglycemia seen in the Somogyi effect.
Question 709: A 44-year-old woman is admitted after an episode of dizziness and palpitations with a subsequent loss of consciousness. At the time of admission, the patient is alert, but then quickly becomes lethargic and reports reoccurrence of palpitations. Past medical history is significant for an episode of ventricular tachycardia 4 months ago, now managed with pharmacologic antiarrhythmic prophylaxis. An ECG is obtained and is shown on the image. Which of the following antiarrhythmic drugs is most likely responsible for this patient's condition?
A. Sotalol (Correct Answer)
B. Diltiazem
C. Verapamil
D. Propranolol
E. Lidocaine
Explanation: ***Sotalol***
- The ECG shows **Torsades de Pointes**, a polymorphic ventricular tachycardia often triggered by **QT prolongation**.
- Sotalol is a **Class III antiarrhythmic** (K+ channel blocker) with **negative chronotropic and inotropic effects**, which can cause **QT prolongation** and thus lead to Torsades de Pointes.
*Diltiazem*
- Diltiazem is a **non-dihydropyridine calcium channel blocker** (Class IV antiarrhythmic) primarily used for **rate control in supraventricular arrhythmias**.
- It does not typically prolong the QT interval and is therefore **unlikely to cause Torsades de Pointes**.
*Verapamil*
- Verapamil, like diltiazem, is a **non-dihydropyridine calcium channel blocker** (Class IV antiarrhythmic) used for **rate control in supraventricular tachycardias**.
- It also does not commonly cause QT prolongation or Torsades de Pointes.
*Propranolol*
- Propranolol is a **non-selective beta-blocker** (Class II antiarrhythmic) used to slow heart rate and reduce myocardial contractility.
- It generally **shortens the QT interval** or has no effect, making it an unlikely cause of Torsades de Pointes.
*Lidocaine*
- Lidocaine is a **Class Ib antiarrhythmic** (Na+ channel blocker) primarily used for **ventricular arrhythmias**, especially post-MI.
- It **shortens the action potential duration** and often **shortens the QT interval**, thus it does not cause Torsades de Pointes.
Question 710: A 48-year-old homeless man is brought to the emergency department 2 hours after his right arm was burned by a fire. He is diagnosed with extensive third-degree burns of the right forearm and upper arm and is admitted to the hospital for debridement and grafting. During his stay in the hospital, he suddenly develops confusion and agitation. Neurologic examination shows horizontal nystagmus and a broad-based gait. Laboratory studies show decreased erythrocyte transketolase activity. Administration of which of the following most likely caused this patient's current condition?
A. Cobalamin
B. Glucose (Correct Answer)
C. Aspirin
D. Hypertonic saline
E. Haloperidol
Explanation: **Glucose**
- The patient's symptoms (confusion, agitation, nystagmus, broad-based gait) and decreased **erythrocyte transketolase activity** are classic signs of **Wernicke-Korsakoff syndrome**, caused by **thiamine (vitamin B1) deficiency**.
- *Administering glucose without prior thiamine supplementation* can precipitate or worsen Wernicke-Korsakoff syndrome because glucose metabolism requires thiamine as a cofactor, further depleting already low stores.
*Cobalamin*
- **Cobalamin (vitamin B12) deficiency** typically causes **megaloblastic anemia** and **neurological symptoms** like peripheral neuropathy, subacute combined degeneration, and cognitive impairment, but not the acute presentation of confusion, agitation, nystagmus, and ataxia seen here.
- It is not directly linked to transketolase activity.
*Aspirin*
- **Aspirin** is an antiplatelet and anti-inflammatory drug. Overdose can cause **salicylate toxicity**, leading to metabolic acidosis, tinnitus, and hyperthermia, but not the specific neurological symptoms or biochemical changes described.
- It is not associated with Wernicke-Korsakoff syndrome.
*Hypertonic saline*
- **Hypertonic saline** is used to treat severe hyponatremia. Rapid correction can lead to **osmotic demyelination syndrome (central pontine myelinolysis)**, causing severe neurological deficits and locked-in syndrome.
- This condition presents differently from the patient's symptoms and is not related to thiamine metabolism.
*Haloperidol*
- **Haloperidol** is an antipsychotic medication. Side effects can include **extrapyramidal symptoms** (dystonia, akathisia, parkinsonism), sedation, and QT prolongation.
- It does not cause Wernicke-Korsakoff syndrome or affect erythrocyte transketolase activity.
