A 34-year-old woman presents to the physician because of fever and sore throat for 2 days. She also reports generalized body pain and fatigue over this period. She was diagnosed with Graves’ disease 6 months ago. Because of arthralgias and rash due to methimazole 3 months ago, her physician switched methimazole to PTU. She appears ill. The vital signs include: temperature 38.4℃ (101.1℉), pulse 88/min, respiratory rate 12/min, and blood pressure 120/80 mm Hg. A 1 × 1 cm ulcer is seen on the side of the tongue and is painful with surrounding erythema. Examination of the neck, lungs, heart, and abdomen shows no abnormalities. She had normal liver aminotransferases last week. Which of the following is the most important diagnostic study at this time?
Q582
An 11-year-old girl is brought to the emergency department after she fell during a dance class. She was unable to stand after the accident and has a painful and swollen knee. On presentation she says that she has had 2 previous swollen joints as well as profuse bleeding after minor cuts. Based on her presentation, a panel of bleeding tests is obtained with the following results:
Bleeding time: 11 minutes
Prothrombin time: 12 seconds
Partial thromboplastin time: 52 seconds
Which of the following treatments would be most effective in treating this patient's condition?
Q583
A 33-year-old man presents to the emergency department with agitation and combativeness. The paramedics who brought him in say that he was demonstrating violent, reckless behavior and was running into oncoming traffic. Chemical sedation is required to evaluate the patient. Physical examination reveals horizontal and vertical nystagmus, tachycardia, and profuse diaphoresis. Which of the following is the most likely causative agent in this patient?
Q584
A 46-year-old male with a history of recurrent deep venous thromboses on warfarin presents to his hematologist for a follow-up visit. He reports that he feels well and has no complaints. His INR at his last visit was 2.5 while his current INR is 4.0. His past medical history is also notable for recent diagnoses of hypertension, hyperlipidemia, and gastroesophageal reflux disease. He also has severe seasonal allergies. He reports that since his last visit, he started multiple new medications at the recommendation of his primary care physician. Which of the following medications was this patient likely started on?
Q585
A 35-year-old woman presents to her primary care physician for recurrent deep venous thrombosis (DVT) of her left lower extremity. She is a vegetarian and often struggles to maintain an adequate intake of non-animal based protein. She currently smokes 1 pack of cigarettes per day, drinks a glass of wine per day, and currently denies any illicit drug use, although she endorses a history of heroin use (injection). Her past medical history is significant for 4 prior admissions for lower extremity swelling and pain that resulted in diagnoses of deep venous thrombosis. Her vital signs include: temperature, 36.7°C (98.0°F); blood pressure, 126/74 mm Hg; heart rate, 87/min; and respiratory rate, 16/min. On physical examination, her pulses are bounding, the patient's complexion is pale, breath sounds are clear, and heart sounds are normal. The spleen is mildly enlarged. She is admitted for DVT treatment and a full hypercoagulability workup. Which of the following is the best initial management for this patient?
Q586
A 67-year-old man presents to his physician with increased thirst and polyuria for the past 4 months. Patient also notes a decrease in his vision for the past 6 months and tingling in his feet. The medical history is significant for a chronic pyelonephritis and stage 2 chronic kidney disease. The current medications include losartan and atorvastatin. He reports a daily alcohol intake of 3 glasses of whiskey. The blood pressure is 140/90 mm Hg and the heart rate is 63/min. The BMI is 35.4 kg/m2. On physical examination, there is 2+ pitting edema of the lower legs and face. The pulmonary, cardiac, and abdominal examinations are within normal limits. There is no costovertebral angle tenderness noted. Ophthalmoscopy shows numerous microaneurysms and retinal hemorrhages concentrated in the fundus. The neurological examination reveals a symmetric decrease in vibration and 2 point discrimination in the patient’s feet and legs extending up to the lower third of the calves. The ankle-deep tendon reflexes are decreased bilaterally. The laboratory test results are as follows:
Serum glucose (fasting) 140 mg/dL
HbA1c 8.5%
BUN 27 mg/dL
Serum creatinine 1.3 mg/dL
eGFR 55 mL/min
The patient is prescribed the first-line drug recommended for his condition. Which of the following side effect is associated with this drug?
Q587
A 50-year-old woman comes to the physician because of palpitations and irritability. Over the past 4 months, she has had several episodes of heart racing and skipping beats that lasted between 30 seconds and several hours. She has also been arguing with her husband more, often about the temperature being too warm. The patient has also lost 8.8-kg (19.4-lb) over the past 4 months, despite being less strict with her diet. She has mild asthma treated with inhaled bronchodilators. Her pulse is 102/min and blood pressure is 148/98 mm Hg. On physical examination, the skin is warm and moist. A mass is palpated in the anterior neck area. On laboratory studies, thyroid stimulating hormone is undetectable and there are antibodies against the thyrotropin-receptor. Thyroid scintigraphy shows diffusely increased iodine uptake. Two weeks later, a single oral dose of radioactive iodine is administered. This patient will most likely require which of the following in the long-term?
Q588
A 22-year-old man is brought to the emergency department by his roommate 20 minutes after being discovered unconscious at home. On arrival, he is unresponsive to painful stimuli. His pulse is 65/min, respirations are 8/min, and blood pressure is 110/70 mm Hg. Pulse oximetry shows an oxygen saturation of 75%. Despite appropriate lifesaving measures, he dies. The physician suspects that he overdosed. If the suspicion is correct, statistically, the most likely cause of death is overdose with which of the following groups of drugs?
Q589
A 35-year-old male patient is brought into the emergency department by emergency medical services. The patient has a history of schizophrenia and is on medication per his mother. His mother also states that the dose of his medication was recently increased, though she is not sure of the specific medication he takes. His vitals are HR 110, BP 170/100, T 102.5, RR 22. On exam, he cannot respond to questions and has rigidity. His head is turned to the right and remains in that position during the exam. Labs are significant for a WBC count of 14,000 cells/mcL, with a creatine kinase (CK) level of 3,000 mcg/L. What is the best treatment for this patient?
Q590
A 38-year-old man presents with a 1-year history of resting tremor and clumsiness in his right hand. He says his symptoms are progressively worsening and are starting to interfere with his work. He has no significant past medical history and is not currently taking any medications. The patient denies any smoking history, alcohol, or recreational drug use. Family history is significant for his grandfather, who had a tremor, and his father, who passed away at a young age. Neither his brother nor his sister have tremors. Vital signs include: pulse 70/min, respiratory rate 15/min, blood pressure 124/70 mm Hg, and temperature 36.7°C (98.1°F). Physical examination reveals decreased facial expression, hypophonia, resting tremor in the right hand, rigidity in the upper limbs, and normal deep tendon reflexes. No abnormalities of posture are seen and gait is normal except for decreased arm swing on the right. The remainder of the exam is unremarkable. Which of the following medications would be most effective in treating this patient's movement problems?
Autonomic/CV Drugs US Medical PG Practice Questions and MCQs
Question 581: A 34-year-old woman presents to the physician because of fever and sore throat for 2 days. She also reports generalized body pain and fatigue over this period. She was diagnosed with Graves’ disease 6 months ago. Because of arthralgias and rash due to methimazole 3 months ago, her physician switched methimazole to PTU. She appears ill. The vital signs include: temperature 38.4℃ (101.1℉), pulse 88/min, respiratory rate 12/min, and blood pressure 120/80 mm Hg. A 1 × 1 cm ulcer is seen on the side of the tongue and is painful with surrounding erythema. Examination of the neck, lungs, heart, and abdomen shows no abnormalities. She had normal liver aminotransferases last week. Which of the following is the most important diagnostic study at this time?
A. No further testing is indicated
B. Complete blood count with differential (Correct Answer)
C. Erythrocyte sedimentation rate
D. Thyroid-stimulating hormone
E. Alanine aminotransferase
Explanation: ***Complete blood count with differential***
- The patient's history of **Grave's disease** managed with **propylthiouracil (PTU)**, combined with symptoms of fever, sore throat, and oral ulcer, points to a high suspicion for **agranulocytosis**.
- A **CBC with differential** is critical to assess the **neutrophil count**, which would be severely low in agranulocytosis.
*No further testing is indicated*
- This statement is incorrect because the patient's symptoms (fever, sore throat, oral ulcer) in the context of PTU use are highly concerning for **adverse drug reactions**, particularly **agranulocytosis**, which requires immediate investigation.
- Delaying testing could lead to severe, potentially life-threatening complications due to **neutropenia** and increased susceptibility to infection.
*Erythrocyte sedimentation rate*
- While an **ESR** would likely be elevated due to the inflammatory response from fever and infection, it is a **non-specific marker** of inflammation.
- It would not provide the crucial information about the **neutrophil count** needed to diagnose or rule out agranulocytosis.
*Thyroid-stimulating hormone*
- The patient's **Graves' disease** is already diagnosed, and she is undergoing treatment. Her current symptoms are acute and unlikely to be directly related to fluctuations in **TSH levels**.
- A **TSH test** would not help diagnose the acute febrile illness or potential adverse drug reaction she is experiencing.
*Alanine aminotransferase*
- Although **PTU** can cause **hepatotoxicity**, the patient's **ALT** levels were normal last week, and her primary symptoms (fever, sore throat, oral ulcer) are not typical for acute liver injury.
- While liver function might be monitored periodically in patients on PTU, it is not the most immediate or relevant diagnostic study for her current acute presentation.
Question 582: An 11-year-old girl is brought to the emergency department after she fell during a dance class. She was unable to stand after the accident and has a painful and swollen knee. On presentation she says that she has had 2 previous swollen joints as well as profuse bleeding after minor cuts. Based on her presentation, a panel of bleeding tests is obtained with the following results:
Bleeding time: 11 minutes
Prothrombin time: 12 seconds
Partial thromboplastin time: 52 seconds
Which of the following treatments would be most effective in treating this patient's condition?
A. Vitamin K
B. Factor VIII repletion
C. Factor VII repletion
D. Desmopressin (Correct Answer)
E. Platelet infusion
Explanation: ***Desmopressin***
- The patient's history of **easy bruising and bleeding**, along with a **prolonged bleeding time** and **normal PT/prolonged PTT**, is highly suggestive of **von Willebrand disease (vWD)**, specifically type 1 given the bleeding time.
- **Desmopressin (DDAVP)** is the treatment of choice for vWD, as it stimulates the release of **endogenous von Willebrand factor (vWF)** and factor VIII from endothelial cells, improving both primary hemostasis and the intrinsic coagulation pathway.
*Vitamin K*
- **Vitamin K** is essential for the synthesis of functioning **coagulation factors II, VII, IX, and X**, as well as proteins C and S.
- This patient's **normal prothrombin time (PT)** suggests that the extrinsic and common pathways, which are dependent on adequate levels of vitamin K-dependent factors, are functioning adequately.
*Factor VIII repletion*
- Isolated **Factor VIII deficiency** (hemophilia A) would present with a **prolonged PTT** and **normal bleeding time**, as primary hemostasis (platelet plug formation) would be unaffected.
- In this patient, the **prolonged bleeding time** indicates a primary hemostasis defect, which is not directly corrected by Factor VIII repletion alone.
*Factor VII repletion*
- **Factor VII deficiency** primarily affects the **extrinsic coagulation pathway**, which would result in a **prolonged prothrombin time (PT)**.
- This patient has a **normal PT**, ruling out Factor VII deficiency as the primary cause of her bleeding disorder.
*Platelet infusion*
- A **prolonged bleeding time** can indicate a **quantitative (thrombocytopenia)** or **qualitative (platelet dysfunction)** defect in platelets.
- While platelet dysfunction is characteristic of vWD due to impaired platelet adhesion, **platelet infusions are generally not indicated for vWD** unless other therapies fail or in severe, life-threatening bleeding with very low vWF levels, as the issue is typically not a lack of platelets themselves but rather a lack of functional vWF to mediate their adhesion.
Question 583: A 33-year-old man presents to the emergency department with agitation and combativeness. The paramedics who brought him in say that he was demonstrating violent, reckless behavior and was running into oncoming traffic. Chemical sedation is required to evaluate the patient. Physical examination reveals horizontal and vertical nystagmus, tachycardia, and profuse diaphoresis. Which of the following is the most likely causative agent in this patient?
A. Cocaine
B. Lysergic acid diethylamide (LSD)
C. Gamma-hydroxybutyric acid (GHB)
D. Phencyclidine (PCP) (Correct Answer)
E. Cannabis
Explanation: ***Phencyclidine (PCP)***
- The combination of **agitation, combativeness, reckless behavior, nystagmus (both horizontal and vertical), tachycardia, and diaphoresis** is highly characteristic of PCP intoxication.
- PCP is known to cause **dissociative anesthetic effects** leading to profound behavioral disturbances, psychotic symptoms, and a distinctive pattern of nystagmus.
*Cocaine*
- Cocaine intoxication presents with **agitation, tachycardia, and diaphoresis**, but typically does not cause **nystagmus**, especially not vertical nystagmus.
- While it can cause psychosis and paranoia, the **dissociative and anesthetic features** seen with PCP are absent.
*Lysergic acid diethylamide (LSD)*
- LSD primarily causes **hallucinations, perceptual distortions, and altered thought processes**, without the prominent **psychomotor agitation, combativeness, and nystagmus** seen in this patient.
- While it can cause some autonomic effects, the clinical picture is not consistent with an LSD "bad trip."
*Gamma-hydroxybutyric acid (GHB)*
- GHB is typically a **CNS depressant** that can cause sedation, coma, bradycardia, and respiratory depression, particularly at higher doses.
- It does not cause the **agitation, combativeness, nystagmus, and sympathetic overactivity** described in the patient.
*Cannabis*
- Cannabis intoxication typically presents with **euphoria, relaxation, altered perception of time, and conjunctival injection**, with occasional mild anxiety or paranoia.
- It does not cause the severe **agitation, combativeness, profound nystagmus, and sympathetic activation** observed in this patient.
Question 584: A 46-year-old male with a history of recurrent deep venous thromboses on warfarin presents to his hematologist for a follow-up visit. He reports that he feels well and has no complaints. His INR at his last visit was 2.5 while his current INR is 4.0. His past medical history is also notable for recent diagnoses of hypertension, hyperlipidemia, and gastroesophageal reflux disease. He also has severe seasonal allergies. He reports that since his last visit, he started multiple new medications at the recommendation of his primary care physician. Which of the following medications was this patient likely started on?
A. Cetirizine
B. Hydrochlorothiazide
C. Omeprazole (Correct Answer)
D. Lisinopril
E. Atorvastatin
Explanation: ***Omeprazole***
- **Omeprazole** is a **proton pump inhibitor (PPI)** commonly prescribed for gastroesophageal reflux disease (GERD).
- PPIs like omeprazole are known to **inhibit CYP2C19**, an enzyme responsible for metabolizing **warfarin**, leading to increased warfarin levels and a higher **INR**.
*Cetirizine*
- **Cetirizine** is an antihistamine used for allergies, and it generally has a **negligible interaction** with warfarin.
- While it can cause some sedation, it does not significantly alter **warfarin metabolism** or INR.
*Hydrochlorothiazide*
- **Hydrochlorothiazide** is a diuretic used for hypertension, and its interaction with warfarin is typically **minimal** or can sometimes *decrease* INR due to fluid loss concentrating clotting factors.
- It would not explain the observed **increase in INR** from 2.5 to 4.0.
*Lisinopril*
- **Lisinopril** is an ACE inhibitor used for hypertension and generally has **no significant interaction** with warfarin.
- It does not inhibit or induce the **cytochrome P450 enzymes** involved in warfarin metabolism.
*Atorvastatin*
- **Atorvastatin** is a statin used for hyperlipidemia, and while some statins can slightly affect INR, **atorvastatin's effect is generally minor** and unpredictable, not typically causing such a significant jump.
- Its metabolic pathway does not strongly inhibit the **CYP enzymes** critical for warfarin breakdown.
Question 585: A 35-year-old woman presents to her primary care physician for recurrent deep venous thrombosis (DVT) of her left lower extremity. She is a vegetarian and often struggles to maintain an adequate intake of non-animal based protein. She currently smokes 1 pack of cigarettes per day, drinks a glass of wine per day, and currently denies any illicit drug use, although she endorses a history of heroin use (injection). Her past medical history is significant for 4 prior admissions for lower extremity swelling and pain that resulted in diagnoses of deep venous thrombosis. Her vital signs include: temperature, 36.7°C (98.0°F); blood pressure, 126/74 mm Hg; heart rate, 87/min; and respiratory rate, 16/min. On physical examination, her pulses are bounding, the patient's complexion is pale, breath sounds are clear, and heart sounds are normal. The spleen is mildly enlarged. She is admitted for DVT treatment and a full hypercoagulability workup. Which of the following is the best initial management for this patient?
A. Begin heparin
B. Begin warfarin, target INR 2.5–3.5
C. Consult IR for IVC filter placement
D. Begin heparin and warfarin (Correct Answer)
E. Begin warfarin, target INR 2.0–3.0
Explanation: ***Begin heparin and warfarin***
- For **acute DVT**, immediate anticoagulation with **heparin** (or another direct thrombin inhibitor/factor Xa inhibitor) is crucial to prevent clot propagation and pulmonary embolism.
- **Warfarin** is started concurrently, as it has a slower onset of action; heparin provides protection until warfarin reaches a therapeutic INR.
*Begin heparin*
- While **heparin** is the correct initial therapy for acute DVT, it is insufficient on its own for long-term management due to its short half-life and need for continuous infusion (unfractionated) or daily injections (low molecular weight).
- A long-term oral anticoagulant like warfarin or a direct oral anticoagulant (DOAC) is necessary for extended prophylaxis, especially in a patient with recurrent DVT.
*Begin warfarin, target INR 2.5–3.5*
- **Warfarin** is appropriate for long-term anticoagulation, but it has a delayed onset of action and requires several days to reach therapeutic levels, during which time the patient would be unprotected from clot extension or embolization.
- The initial target INR for most VTE is 2.0-3.0, though for recurrent events or certain conditions, a higher range might be considered later, but 2.5-3.5 is not the standard initial target.
*Consult IR for IVC filter placement*
- **IVC filters** are typically reserved for patients with an acute DVT who have a **contraindication to anticoagulation** or who experience recurrent PE despite adequate anticoagulation.
- There is no mention of contraindications to anticoagulation in this patient, and filters are not a primary treatment for acute DVT but rather a preventative measure against pulmonary embolism in specific high-risk scenarios.
*Begin warfarin, target INR 2.0–3.0*
- While **warfarin** at an INR target of 2.0-3.0 is a standard long-term therapy for DVT, beginning it alone is inappropriate for acute DVT due to its **delayed therapeutic effect**.
- Without concurrent rapid-acting anticoagulation (like heparin), the patient remains at high risk for complications while awaiting warfarin's full effect.
Question 586: A 67-year-old man presents to his physician with increased thirst and polyuria for the past 4 months. Patient also notes a decrease in his vision for the past 6 months and tingling in his feet. The medical history is significant for a chronic pyelonephritis and stage 2 chronic kidney disease. The current medications include losartan and atorvastatin. He reports a daily alcohol intake of 3 glasses of whiskey. The blood pressure is 140/90 mm Hg and the heart rate is 63/min. The BMI is 35.4 kg/m2. On physical examination, there is 2+ pitting edema of the lower legs and face. The pulmonary, cardiac, and abdominal examinations are within normal limits. There is no costovertebral angle tenderness noted. Ophthalmoscopy shows numerous microaneurysms and retinal hemorrhages concentrated in the fundus. The neurological examination reveals a symmetric decrease in vibration and 2 point discrimination in the patient’s feet and legs extending up to the lower third of the calves. The ankle-deep tendon reflexes are decreased bilaterally. The laboratory test results are as follows:
Serum glucose (fasting) 140 mg/dL
HbA1c 8.5%
BUN 27 mg/dL
Serum creatinine 1.3 mg/dL
eGFR 55 mL/min
The patient is prescribed the first-line drug recommended for his condition. Which of the following side effect is associated with this drug?
A. Lactic acidosis (Correct Answer)
B. Infections
C. Hypoglycemia
D. Iron deficiency anemia
E. Hyperkalemia
Explanation: ***Lactic acidosis***
- The patient presents with classic **Type 2 Diabetes Mellitus** (polyuria, polydipsia, HbA1c 8.5%, fasting glucose 140 mg/dL, diabetic retinopathy, peripheral neuropathy).
- **Metformin** is the first-line medication for Type 2 Diabetes according to all major guidelines (ADA, AACE).
- While **lactic acidosis** is a rare side effect of metformin, it is the most **serious** adverse effect and the answer to this question.
- This patient has multiple risk factors for lactic acidosis: **moderate renal impairment** (eGFR 55 mL/min), **chronic alcohol use** (3 glasses whiskey daily), and advanced age.
- Note: Current guidelines allow metformin use at eGFR ≥30 mL/min with dose adjustment, so metformin is not contraindicated in this patient but requires careful monitoring.
- The most common side effects of metformin are GI-related (diarrhea, nausea), but lactic acidosis is the most clinically significant.
*Infections*
- Increased risk of **genitourinary infections** is associated with **SGLT2 inhibitors** (canagliflozin, empagliflozin, dapagliflozin), not metformin.
- While the patient has a history of chronic pyelonephritis, this is unrelated to metformin therapy.
*Hypoglycemia*
- **Metformin** decreases hepatic glucose production and improves insulin sensitivity without stimulating insulin secretion.
- Metformin monotherapy **rarely causes hypoglycemia**, which is more common with sulfonylureas (glyburide, glipizide) or insulin.
*Iron deficiency anemia*
- Iron deficiency anemia is **not** a recognized side effect of metformin.
- Note: Metformin is associated with **Vitamin B12 deficiency** (due to malabsorption) leading to megaloblastic anemia, but not iron deficiency anemia.
*Hyperkalemia*
- Hyperkalemia is **not** a side effect of metformin.
- This patient's losartan (ARB) and chronic kidney disease could cause hyperkalemia, but this is unrelated to metformin therapy.
Question 587: A 50-year-old woman comes to the physician because of palpitations and irritability. Over the past 4 months, she has had several episodes of heart racing and skipping beats that lasted between 30 seconds and several hours. She has also been arguing with her husband more, often about the temperature being too warm. The patient has also lost 8.8-kg (19.4-lb) over the past 4 months, despite being less strict with her diet. She has mild asthma treated with inhaled bronchodilators. Her pulse is 102/min and blood pressure is 148/98 mm Hg. On physical examination, the skin is warm and moist. A mass is palpated in the anterior neck area. On laboratory studies, thyroid stimulating hormone is undetectable and there are antibodies against the thyrotropin-receptor. Thyroid scintigraphy shows diffusely increased iodine uptake. Two weeks later, a single oral dose of radioactive iodine is administered. This patient will most likely require which of the following in the long-term?
A. Propranolol therapy
B. Near-total thyroidectomy
C. L-thyroxine therapy (Correct Answer)
D. Methimazole therapy
E. Estrogen replacement therapy
Explanation: * ***L-thyroxine therapy***
* Radioactive iodine ablation for **Graves' disease** often leads to **permanent hypothyroidism**, necessitating **lifelong thyroid hormone replacement** with levothyroxine.
* The patient presents with classic **hyperthyroidism** symptoms (palpitations, irritability, weight loss, heat intolerance, warm/moist skin, goiter, undetectable TSH, positive **TSH receptor antibodies**, diffuse uptake on scintigraphy), treated with radioactive iodine.
* *Propranolol therapy*
* Propranolol is a **beta-blocker** used for symptomatic relief of hyperthyroidism, particularly palpitations and tremors.
* It does **not treat the underlying cause** of hyperthyroidism or subsequent hypothyroidism, and therefore is not a long-term solution after successful radioactive iodine therapy.
* *Near-total thyroidectomy*
* A near-total thyroidectomy is a surgical option for hyperthyroidism, especially in cases of very large goiters, contraindications to radioactive iodine, or malignancy.
* While it also often leads to **hypothyroidism** requiring long-term L-thyroxine, it was **not the chosen treatment modality** in this scenario (radioactive iodine was administered).
* *Methimazole therapy*
* Methimazole is an **antithyroid drug** used to decrease thyroid hormone synthesis in hyperthyroidism.
* It is used as a **primary treatment for hyperthyroidism** or as preparation for definitive therapy like radioactive iodine or surgery; it is not a long-term treatment after successful radioactive iodine ablation has induced hypothyroidism.
* *Estrogen replacement therapy*
* Estrogen replacement therapy is used for symptoms of **menopause** or to prevent osteoporosis, but it has no direct role in the management of thyroid disorders.
* The patient's symptoms are clearly indicative of a **thyroid pathology**, not primarily menopausal symptoms.
Question 588: A 22-year-old man is brought to the emergency department by his roommate 20 minutes after being discovered unconscious at home. On arrival, he is unresponsive to painful stimuli. His pulse is 65/min, respirations are 8/min, and blood pressure is 110/70 mm Hg. Pulse oximetry shows an oxygen saturation of 75%. Despite appropriate lifesaving measures, he dies. The physician suspects that he overdosed. If the suspicion is correct, statistically, the most likely cause of death is overdose with which of the following groups of drugs?
A. Benzodiazepines
B. Opioid analgesics (Correct Answer)
C. Acetaminophen
D. Antidepressants
E. Amphetamines
Explanation: ***Opioid analgesics***
- The patient's presentation with **unresponsiveness**, **respiratory depression** (respirations 8/min, SpO2 75%), and **bradycardia** is highly characteristic of severe opioid overdose.
- Opioids suppress the **respiratory drive** through their action on mu-opioid receptors in the brainstem, leading to hypoventilation, hypoxemia, and ultimately death if untreated.
- **Statistically**, opioids are the leading cause of fatal drug overdoses in the United States.
*Benzodiazepines*
- While benzodiazepine overdose can cause significant **CNS depression** and unresponsiveness, it is less likely to cause such profound and rapid respiratory depression as the sole agent, particularly with a relatively preserved blood pressure.
- Benzodiazepines primarily enhance the effect of **GABA**, leading to sedation and anxiolysis, but typically have a wider therapeutic index for respiratory depression compared to opioids.
*Acetaminophen*
- Acetaminophen overdose primarily causes **hepatotoxicity** (liver damage), which develops over 24-72 hours, not immediate death from respiratory depression.
- Acute overdose symptoms may initially be mild or absent, with liver failure manifesting hours to days later, which does not fit the rapid demise in this case.
*Antidepressants*
- Overdoses with antidepressants, especially **tricyclic antidepressants (TCAs)**, can cause cardiac arrhythmias, seizures, and CNS depression.
- However, the primary cause of death is typically from **cardiac toxicity** or intractable seizures, not the profound respiratory depression seen here.
*Amphetamines*
- Amphetamine overdose is characterized by **CNS stimulation**, including agitation, hyperthermia, tachycardia, hypertension, and seizures, with respiratory failure often secondary to status epilepticus or cardiovascular collapse.
- This presentation is the opposite of the patient's severe CNS and respiratory depression.
Question 589: A 35-year-old male patient is brought into the emergency department by emergency medical services. The patient has a history of schizophrenia and is on medication per his mother. His mother also states that the dose of his medication was recently increased, though she is not sure of the specific medication he takes. His vitals are HR 110, BP 170/100, T 102.5, RR 22. On exam, he cannot respond to questions and has rigidity. His head is turned to the right and remains in that position during the exam. Labs are significant for a WBC count of 14,000 cells/mcL, with a creatine kinase (CK) level of 3,000 mcg/L. What is the best treatment for this patient?
A. Valproate
B. Morphine
C. Dantrolene (Correct Answer)
D. Diazepam
E. Lamotrigine
Explanation: ***Dantrolene***
- This patient presents with symptoms highly suggestive of **neuroleptic malignant syndrome (NMS)**, including a history of schizophrenia, recent medication increase, fever, rigidity, autonomic instability (tachycardia, hypertension), elevated WBC, and elevated CK.
- **Dantrolene** is a **direct-acting skeletal muscle relaxant** that reduces muscle rigidity and hyperthermia by inhibiting calcium release from the sarcoplasmic reticulum.
- In **severe NMS** with marked hyperthermia (T 102.5°F), significant muscle rigidity, and elevated CK (indicating rhabdomyolysis risk), Dantrolene is the most appropriate pharmacologic intervention to directly address the life-threatening muscle rigidity and prevent further complications.
*Valproate*
- **Valproate** is an **anticonvulsant** and **mood stabilizer** used for seizures, bipolar disorder, and migraine prevention.
- It does not directly address the pathophysiology of NMS, which involves central dopamine receptor blockade and muscle rigidity.
*Morphine*
- **Morphine** is an **opioid analgesic** primarily used for pain management.
- It would not alleviate the underlying muscle rigidity, hyperthermia, or autonomic dysfunction associated with NMS and could potentially worsen respiratory depression.
*Diazepam*
- **Diazepam** is a **benzodiazepine** used for anxiety, seizures, and muscle spasms, and can be helpful for agitation or mild rigidity.
- While it might provide some symptomatic relief and is used as adjunctive therapy in NMS, it is not the primary treatment for **severe NMS** with this degree of hyperthermia, marked rigidity, and elevated CK, and does not directly address the underlying muscle damage and rhabdomyolysis risk as effectively as Dantrolene.
*Lamotrigine*
- **Lamotrigine** is an **anticonvulsant** used for seizures and bipolar disorder, known for its risk of severe skin reactions.
- It has no role in the treatment of NMS and would not impact the patient's severe symptoms.
Question 590: A 38-year-old man presents with a 1-year history of resting tremor and clumsiness in his right hand. He says his symptoms are progressively worsening and are starting to interfere with his work. He has no significant past medical history and is not currently taking any medications. The patient denies any smoking history, alcohol, or recreational drug use. Family history is significant for his grandfather, who had a tremor, and his father, who passed away at a young age. Neither his brother nor his sister have tremors. Vital signs include: pulse 70/min, respiratory rate 15/min, blood pressure 124/70 mm Hg, and temperature 36.7°C (98.1°F). Physical examination reveals decreased facial expression, hypophonia, resting tremor in the right hand, rigidity in the upper limbs, and normal deep tendon reflexes. No abnormalities of posture are seen and gait is normal except for decreased arm swing on the right. The remainder of the exam is unremarkable. Which of the following medications would be most effective in treating this patient's movement problems?
A. Bromocriptine
B. Selegiline
C. Benztropine
D. Levodopa/carbidopa (Correct Answer)
E. Entacapone
Explanation: ***Levodopa/carbidopa***
- The patient's symptoms, including **resting tremor**, **rigidity**, **bradykinesia** (decreased facial expression, hypophonia, decreased arm swing), and progressive worsening, are classic for **Parkinson's disease**.
- **Levodopa/carbidopa** is the **most effective treatment** for motor symptoms in Parkinson's disease, providing significant relief by replenishing dopamine levels in the brain.
- While some clinicians may delay levodopa in younger patients (<65 years) to postpone long-term complications like dyskinesias, it remains the **most effective option** for symptom control when treatment is needed.
*Bromocriptine*
- This is a **dopamine agonist** that can be used for Parkinson's disease and may be considered as initial therapy in younger patients to delay levodopa exposure.
- However, it is generally **less effective than levodopa/carbidopa** for motor symptom control and often causes more side effects, including impulse control disorders, hallucinations, and peripheral edema.
- The question asks for the **most effective** medication, which is levodopa/carbidopa.
*Selegiline*
- **Selegiline** is a **MAO-B inhibitor** that helps prevent the breakdown of dopamine, offering mild symptomatic benefit in early Parkinson's disease or as an adjunct therapy.
- It is not as potent as levodopa/carbidopa in addressing significant motor symptoms and would likely be insufficient for this patient's functionally impairing symptoms.
*Benztropine*
- **Benztropine** is an **anticholinergic medication** primarily used to treat tremors and dystonia, often in younger patients or for drug-induced parkinsonism.
- It is less effective for **bradykinesia** and **rigidity** and carries a higher risk of side effects like cognitive impairment, dry mouth, constipation, and urinary retention.
*Entacapone*
- **Entacapone** is a **COMT inhibitor** that extends the half-life of levodopa by preventing its peripheral breakdown.
- It is used only as an **adjunct therapy to levodopa/carbidopa** to improve its efficacy and reduce "wearing-off" symptoms, not as monotherapy for Parkinson's disease.