A 60-year-old African-American female presents to your office complaining of dysuria, paresthesias, and blurry vision. Her body mass index is 37.2 kg/m2. Which of the following drugs would most significantly increase the levels of C-peptide in the blood when administered to this patient?
Q882
A 54-year-old man comes to the physician for a health maintenance examination. He feels well. He is 173 cm (5 ft 8 in) tall and weighs 84 kg (185 lb); BMI is 28 kg/m2. His vital signs are within normal limits. Physical examination shows no abnormalities. Serum lipid studies show:
Total cholesterol 280 mg/dL
HDL-cholesterol 30 mg/dL
LDL-cholesterol 195 mg/dL
Triglycerides 275 mg/dL
Treatment with atorvastatin and cholestyramine is initiated. Which of the following changes is most likely induced by both agents?
Q883
A 71-year-old woman comes to the physician because of palpitations and shortness of breath that started 3 days ago. She has hypertension and congestive heart failure. Her pulse is 124/min, and blood pressure is 130/85 mm Hg. Cardiac examination shows an irregularly irregular rhythm without any murmurs. An ECG shows a narrow-complex tachycardia without P waves. The patient is prescribed a prophylactic medication that can be reversed with idarucizumab. The expected beneficial effect of the prescribed drug is most likely due to which of the following effects?
Q884
A 32-year-old woman comes to the physician because of pain and stiffness in both of her hands for the past 3 weeks. The pain is most severe early in the day and does not respond to ibuprofen. She has no history of serious illness and takes no medications. Vital signs are within normal limits. Examination shows swelling and tenderness of the wrists and metacarpophalangeal joints bilaterally. Range of motion is decreased due to pain. There are subcutaneous, nontender, firm, mobile nodules on the extensor surface of the forearm. Which of the following is the most appropriate pharmacotherapy for this patient's current symptoms?
Q885
A 59-year-old man with a history of congestive heart failure presents to his cardiologist for a follow-up visit. His past medical history is notable for diabetes mellitus, hypertension, and obesity. He takes metformin, glyburide, aspirin, lisinopril, and metoprolol. He has a 40 pack-year smoking history and drinks alcohol socially. His temperature is 99.1°F (37.2°C), blood pressure is 150/65 mmHg, pulse is 75/min, and respirations are 20/min. Physical examination reveals bilateral rales at the lung bases and 1+ edema in the bilateral legs. The physician decides to start the patient on an additional diuretic but warns the patient about an increased risk of breast enlargement. Which of the following is the most immediate physiologic effect of the medication in question?
Q886
A 24-year-old woman comes to the physician because of bothersome hair growth on her face and abdomen over the past 8 years. She does not take any medications. She is 163 cm (5 ft 4 in) tall and weighs 85 kg (187 lb); BMI is 32 kg/m2. Physical examination shows coarse dark hair on the upper lip and periumbilical and periareolar skin. Her external genitalia appear normal. Her serum follicle-stimulating hormone, luteinizing hormone, and testosterone are within the reference range. A urine pregnancy test is negative. Which of the following is the most appropriate pharmacotherapy for this patient's condition at this time?
Q887
A 23-year-old man is brought to the emergency department by police at 2:00 AM. They picked him up from a local nightclub, where he was yelling and threatening to fight the staff. A review of his medical record is unremarkable. At the hospital, his behavior continues to be agitated and bizarre. His temperature is 37.0°C (98.6°F), the blood pressure is 162/98 mm Hg, the heart rate is 120/min, the respiratory rate is 18/min, and the oxygen saturation is 99% on room air. The physical exam is notable for agitation, but otherwise, he appears healthy. His thin nasal mucosa oozes blood and his pupils are 6mm, equal, and reactive to light. His speech is pressured and bizarre. He insists the hospital should let him go because "I am in the FBI". Urine toxicology is sent to the laboratory for analysis. Which of the following is the most likely cause of this patient's presentation?
Q888
A 37-year-old male presents to general medical clinic reporting sleeping difficulties. He states that he has daytime sleepiness, having fallen asleep several times while driving his car recently. He sometimes experiences very vivid dreams just before awakening. You ask the patient's wife if she has witnessed any episodes where her husband lost all muscle tone and fell to the ground, and she confirms that he has not had this symptom. The patient notes that this condition runs in his family, and he desperately asks for treatment. You begin him on a first-line medication for this illness, which works by which mechanism of action?
Q889
A 51-year-old man is bitten by a cottonmouth viper and is successfully treated with sheep hyperimmune Fab antivenom. Three days later, the patient develops an abdominal itchy rash and re-presents to the emergency department for medical care. His medical history is significant for gout, hypertension, hypercholesterolemia, diabetes mellitus type II, and multiple basal cell carcinomas on his face and neck. He currently smokes 1 pack of cigarettes per day, drinks a 6-pack of beer per day, and denies any current illicit drug use. His vital signs include: temperature 40.0°C (104.0°F), blood pressure 126/74 mm Hg, heart rate 111/min, and respiratory rate 23/min. On physical examination, his gait is limited by diffuse arthralgias, lung sounds are clear bilaterally, and he has normal heart sounds. The patient has a pruritic periumbilical serpiginous macular rash that has spread to involve the back, upper trunk, and extremities. Of the following options, which is the next best step in patient management?
Q890
A 34-year-old woman is recovering in the post-operative unit following a laparoscopic procedure for chronic endometriosis. She had initially presented with complaints of painful menstrual cramps that kept her bedridden most of the day. She also mentioned to her gynecologist that she had been diagnosed with endometriosis 4 years ago, and she could not find a medication or alternative therapeutic measure that helped. Her medical history was significant for surgery she had 6 years ago to remove tumors she had above her kidneys, after which she was prescribed hydrocortisone. An hour after the laparoscopic procedure, she calls the nurse because she is having difficulty breathing. The nurse records her vital signs include: blood pressure 85/55 mm Hg, respirations 20/min, and pulse 115/min. The patient suddenly loses consciousness. Intravenous fluids are started immediately. She gains consciousness, but her blood pressure is unchanged. Which of the following is the most likely cause of the hypotension?
Autonomic/CV Drugs US Medical PG Practice Questions and MCQs
Question 881: A 60-year-old African-American female presents to your office complaining of dysuria, paresthesias, and blurry vision. Her body mass index is 37.2 kg/m2. Which of the following drugs would most significantly increase the levels of C-peptide in the blood when administered to this patient?
A. Acarbose
B. Glipizide (Correct Answer)
C. Insulin
D. Metformin
E. NPH
Explanation: ***Glipizide***
- **Glipizide** is a **sulfonylurea** that stimulates insulin secretion from pancreatic beta cells, leading to increased C-peptide levels.
- Increased insulin secretion by glipizide is independent of meals and can cause **hypoglycemia**.
*Acarbose*
- **Acarbose** is an **alpha-glucosidase inhibitor** that delays glucose absorption from the gut, reducing post-prandial glucose spikes.
- It does not directly affect insulin secretion or C-peptide levels.
*Insulin*
- Administering exogenous **insulin** directly lowers blood glucose but does not stimulate endogenous insulin production, and therefore does not increase C-peptide.
- C-peptide is a marker of endogenous insulin secretion; an increase would only be seen if the body produced more insulin.
*Metformin*
- **Metformin** primarily reduces **hepatic glucose production** and improves insulin sensitivity in peripheral tissues.
- It does not directly stimulate insulin secretion from the pancreas and therefore does not increase C-peptide levels.
*NPH*
- **NPH (Neutral Protamine Hagedorn)** is an intermediate-acting exogenous insulin formulation.
- As an exogenous insulin, it does not stimulate the pancreas to produce more insulin or C-peptide.
Question 882: A 54-year-old man comes to the physician for a health maintenance examination. He feels well. He is 173 cm (5 ft 8 in) tall and weighs 84 kg (185 lb); BMI is 28 kg/m2. His vital signs are within normal limits. Physical examination shows no abnormalities. Serum lipid studies show:
Total cholesterol 280 mg/dL
HDL-cholesterol 30 mg/dL
LDL-cholesterol 195 mg/dL
Triglycerides 275 mg/dL
Treatment with atorvastatin and cholestyramine is initiated. Which of the following changes is most likely induced by both agents?
A. Increased hepatic bile salt synthesis
B. Increased LDL receptor expression (Correct Answer)
C. Increased lipoprotein lipase activity
D. Decreased hepatic de novo cholesterol synthesis
E. Increased cholesterol levels in hepatocytes
Explanation: ***Increased LDL receptor expression***
- **Statins** (e.g., atorvastatin) inhibit **HMG-CoA reductase**, leading to decreased intracellular cholesterol and thus upregulating hepatic **LDL receptors** to scavenge more cholesterol from the blood.
- **Bile acid sequestrants** (e.g., cholestyramine) bind bile acids in the gut, interrupting their enterohepatic circulation and increasing their fecal excretion. This increased demand for new bile acid synthesis by the liver depletes hepatocyte cholesterol, causing an upregulation of hepatic **LDL receptors** to acquire more cholesterol.
*Increased hepatic bile salt synthesis*
- **Cholestyramine** (a bile acid sequestrant) directly increases bile salt synthesis by the liver as it depletes the enterohepatic pool of bile acids, but **atorvastatin** (a statin) does not directly increase bile salt synthesis.
- Statins primarily reduce cholesterol synthesis, which is a precursor for bile acids, so their direct effect on bile acid synthesis is not an increase.
*Increased lipoprotein lipase activity*
- Neither **atorvastatin** nor **cholestyramine** primarily function by increasing **lipoprotein lipase (LPL)** activity.
- Fibrates are known to increase LPL activity, which enhances the clearance of **triglyceride-rich lipoproteins**.
*Decreased hepatic de novo cholesterol synthesis*
- **Atorvastatin** directly inhibits **HMG-CoA reductase**, the rate-limiting enzyme in **cholesterol synthesis**, thereby decreasing *de novo* cholesterol production.
- **Cholestyramine** does not directly decrease hepatic *de novo* cholesterol synthesis; instead, it increases cholesterol utilization for bile acid synthesis, which can secondarily influence cholesterol synthesis rates.
*Increased cholesterol levels in hepatocytes*
- Both **atorvastatin** and **cholestyramine** work to *decrease* intracellular **hepatocyte cholesterol levels**.
- Decreased intracellular cholesterol is the trigger for the upregulation of **LDL receptors**, which is the primary mechanism of action for both drugs in reducing circulating LDL.
Question 883: A 71-year-old woman comes to the physician because of palpitations and shortness of breath that started 3 days ago. She has hypertension and congestive heart failure. Her pulse is 124/min, and blood pressure is 130/85 mm Hg. Cardiac examination shows an irregularly irregular rhythm without any murmurs. An ECG shows a narrow-complex tachycardia without P waves. The patient is prescribed a prophylactic medication that can be reversed with idarucizumab. The expected beneficial effect of the prescribed drug is most likely due to which of the following effects?
A. Inhibition of thrombocyte phosphodiesterase III
B. Irreversible inhibition of GPIIb/IIIa complex
C. Induction of conformational change in antithrombin III
D. Direct inhibition of factor Xa
E. Direct inhibition of thrombin (Correct Answer)
Explanation: ***Direct inhibition of thrombin***
- The patient's presentation of **palpitations, shortness of breath, irregular rhythm**, and a **narrow-complex tachycardia without P waves** is consistent with **atrial fibrillation**.
- The mention of a prophylactic medication reversible by **idarucizumab** points to **dabigatran**, a direct thrombin inhibitor (factor IIa).
*Inhibition of thrombocyte phosphodiesterase III*
- This mechanism is characteristic of **cilostazol**, which primarily causes **vasodilation** and **platelet inhibition** and is not reversed by idarucizumab.
- Cilostazol is used for **intermittent claudication**, not typically for stroke prevention in atrial fibrillation.
*Irreversible inhibition of GPIIb/IIIa complex*
- This describes the action of **abciximab**, a platelet aggregation inhibitor mostly used in acute coronary syndromes, which is not reversed by idarucizumab.
- Reversal of GPIIb/IIIa inhibitors often involves platelet transfusions, not specific agents like idarucizumab.
*Induction of conformational change in antithrombin III*
- This mechanism describes **heparin** and **low molecular weight heparins**, which enhance antithrombin's activity against factors IIa and Xa.
- Heparin is reversible with **protamine sulfate**, not idarucizumab.
*Direct inhibition of factor Xa*
- This mechanism belongs to drugs like **rivaroxaban, apixaban**, and **edoxaban** (direct oral anticoagulants or DOACs).
- While these are also commonly used for stroke prevention in atrial fibrillation, their specific reversal agent is **andexanet alfa**, not idarucizumab.
Question 884: A 32-year-old woman comes to the physician because of pain and stiffness in both of her hands for the past 3 weeks. The pain is most severe early in the day and does not respond to ibuprofen. She has no history of serious illness and takes no medications. Vital signs are within normal limits. Examination shows swelling and tenderness of the wrists and metacarpophalangeal joints bilaterally. Range of motion is decreased due to pain. There are subcutaneous, nontender, firm, mobile nodules on the extensor surface of the forearm. Which of the following is the most appropriate pharmacotherapy for this patient's current symptoms?
A. Adalimumab
B. Prednisone (Correct Answer)
C. Methotrexate
D. Colchicine
E. Sulfasalazine
Explanation: ***Prednisone***
- The patient presents with **symmetrical polyarthritis** of the small joints, morning stiffness unresponsive to NSAIDs, and **rheumatoid nodules**, which are classic features of **rheumatoid arthritis (RA)**.
- For **immediate symptom control** of acute RA flares, **glucocorticoids** like prednisone are highly effective in rapidly reducing inflammation and pain.
- In clinical practice, prednisone would be used as **bridge therapy** while initiating disease-modifying therapy, providing symptomatic relief within days.
*Methotrexate*
- Methotrexate is a **disease-modifying antirheumatic drug (DMARD)** and is the **first-line agent for long-term RA management** per current guidelines.
- While this should be initiated promptly in newly diagnosed RA, it has a **slow onset of action (6-12 weeks)** and would not provide immediate relief for the patient's current severe symptoms.
- In practice, methotrexate would be started concurrently with a short course of glucocorticoids.
*Adalimumab*
- Adalimumab is a **TNF-alpha inhibitor**, a **biologic DMARD**, used for moderate to severe RA, typically when conventional DMARDs are insufficient.
- It is **not first-line therapy** for newly diagnosed RA and requires prior screening for latent infections due to **immunosuppression risk**.
- Like methotrexate, it has a delayed onset of action and would not provide rapid symptom relief.
*Colchicine*
- Colchicine is primarily used for the treatment of **gout** and **pseudogout**, by inhibiting neutrophil migration and microtubule polymerization.
- It is **not indicated** for the management of rheumatoid arthritis.
*Sulfasalazine*
- Sulfasalazine is a **conventional synthetic DMARD** used in the treatment of RA, particularly in mild to moderate cases or as combination therapy.
- Like methotrexate, it has a **slow onset of action (weeks to months)** and is not appropriate for rapid symptom control in an acute presentation.
Question 885: A 59-year-old man with a history of congestive heart failure presents to his cardiologist for a follow-up visit. His past medical history is notable for diabetes mellitus, hypertension, and obesity. He takes metformin, glyburide, aspirin, lisinopril, and metoprolol. He has a 40 pack-year smoking history and drinks alcohol socially. His temperature is 99.1°F (37.2°C), blood pressure is 150/65 mmHg, pulse is 75/min, and respirations are 20/min. Physical examination reveals bilateral rales at the lung bases and 1+ edema in the bilateral legs. The physician decides to start the patient on an additional diuretic but warns the patient about an increased risk of breast enlargement. Which of the following is the most immediate physiologic effect of the medication in question?
A. Decreased sodium reabsorption in the distal convoluted tubule
B. Decreased bicarbonate reabsorption in the proximal convoluted tubule
C. Decreased sodium reabsorption in the thick ascending limb
D. Decreased renin enzyme activity
E. Decreased sodium reabsorption in the collecting duct (Correct Answer)
Explanation: ***Decreased sodium reabsorption in the collecting duct***
- The physician is initiating **spironolactone**, an **aldosterone antagonist**, due to its known side effect of **gynecomastia** (breast enlargement).
- Spironolactone acts on the **collecting duct** to inhibit aldosterone's effects, leading to decreased sodium reabsorption and **decreased potassium excretion** (potassium-sparing effect).
- This makes it useful in heart failure but requires monitoring for **hyperkalemia**, especially in patients on ACE inhibitors like lisinopril.
*Decreased sodium reabsorption in the distal convoluted tubule*
- This is the primary site of action for **thiazide diuretics**, such as **hydrochlorothiazide** or **chlorthalidone**.
- While effective for heart failure, thiazides are not associated with breast enlargement.
*Decreased bicarbonate reabsorption in the proximal convoluted tubule*
- This is the main action of **carbonic anhydrase inhibitors**, such as **acetazolamide**.
- These diuretics are typically used for conditions like glaucoma or metabolic alkalosis, not first-line for heart failure and do not cause breast enlargement.
*Decreased sodium reabsorption in the thick ascending limb*
- This is the mechanism of action for **loop diuretics**, such as **furosemide** or **bumetanide**.
- Loop diuretics are potent and frequently used in heart failure, but they do not cause breast enlargement.
*Decreased renin enzyme activity*
- This effect is primarily seen with **beta-blockers** or **direct renin inhibitors**.
- While beta-blockers (like metoprolol, which the patient is already taking) are used in heart failure, they do not cause breast enlargement.
Question 886: A 24-year-old woman comes to the physician because of bothersome hair growth on her face and abdomen over the past 8 years. She does not take any medications. She is 163 cm (5 ft 4 in) tall and weighs 85 kg (187 lb); BMI is 32 kg/m2. Physical examination shows coarse dark hair on the upper lip and periumbilical and periareolar skin. Her external genitalia appear normal. Her serum follicle-stimulating hormone, luteinizing hormone, and testosterone are within the reference range. A urine pregnancy test is negative. Which of the following is the most appropriate pharmacotherapy for this patient's condition at this time?
A. Oral contraceptive (Correct Answer)
B. Metformin
C. Ketoconazole
D. Prednisone
E. Leuprolide
Explanation: ***Oral contraceptive***
- The patient presents with **hirsutism** (coarse dark hair growth) and **obesity** (BMI 32 kg/m2). Despite normal hormone levels, this presentation is highly suggestive of **PCOS**, for which oral contraceptives are the first-line treatment.
- **Oral contraceptives** reduce androgen production by suppressing LH and increasing sex hormone-binding globulin (SHBG), which binds free testosterone, thereby decreasing androgenic effects and improving hirsutism.
*Metformin*
- While metformin is used in PCOS, it primarily targets **insulin resistance** and has a less direct effect on hirsutism compared to oral contraceptives.
- It is often considered in women with PCOS who have significant insulin resistance, type 2 diabetes, or are trying to conceive.
*Ketoconazole*
- **Ketoconazole** is an antifungal drug that can inhibit adrenal and gonadal steroid synthesis but is rarely used for hirsutism due to its potential for **liver toxicity** and other side effects.
- Its use for hirsutism is generally reserved for severe cases of hyperandrogenism not responsive to other treatments, such as in Cushing's syndrome where it can decrease cortisol production.
*Prednisone*
- **Prednisone** is a corticosteroid used to suppress adrenal androgen production in some forms of **congenital adrenal hyperplasia (CAH)**.
- Given the normal hormone levels and absence of other signs of CAH (e.g., ambiguous genitalia at birth, salt-wasting crisis), prednisone is not indicated for this patient's presentation.
*Leuprolide*
- **Leuprolide** is a GnRH agonist that initially stimulates, then downregulates, the pituitary-gonadal axis, leading to a decrease in sex hormone production.
- It is typically used for severe hyperandrogenism, precocious puberty, or endometriosis, and its side effects (e.g., hot flashes, bone loss) make it a less appropriate first-line treatment for hirsutism in this patient.
Question 887: A 23-year-old man is brought to the emergency department by police at 2:00 AM. They picked him up from a local nightclub, where he was yelling and threatening to fight the staff. A review of his medical record is unremarkable. At the hospital, his behavior continues to be agitated and bizarre. His temperature is 37.0°C (98.6°F), the blood pressure is 162/98 mm Hg, the heart rate is 120/min, the respiratory rate is 18/min, and the oxygen saturation is 99% on room air. The physical exam is notable for agitation, but otherwise, he appears healthy. His thin nasal mucosa oozes blood and his pupils are 6mm, equal, and reactive to light. His speech is pressured and bizarre. He insists the hospital should let him go because "I am in the FBI". Urine toxicology is sent to the laboratory for analysis. Which of the following is the most likely cause of this patient's presentation?
A. Cocaine intoxication (Correct Answer)
B. Tetrahydrocannabinol (THC) intoxication
C. Thyrotoxicosis
D. Acute manic episode
E. Phencyclidine (PCP) intoxication
Explanation: ***Cocaine intoxication***
- The patient's presentation with **agitation**, **pressured speech**, **paranoid ideation** (insisting he is in the FBI), **tachycardia**, **hypertension**, and **dilated pupils (mydriasis)** is highly suggestive of cocaine intoxication. The **bloody nasal mucosa** further points to intranasal cocaine use.
- Cocaine is a potent **vasoconstrictor** and **CNS stimulant** that blocks reuptake of norepinephrine, dopamine, and serotonin. The **sympathomimetic effects** cause mydriasis, tachycardia, and hypertension, while vasoconstriction can lead to **nasal septal damage** and epistaxis with intranasal use.
*Phencyclidine (PCP) intoxication*
- While PCP can cause **agitation**, violence, and bizarre behavior, it typically presents with **vertical or rotatory nystagmus**, **ataxia**, and **analgesia**, which are not described in this patient.
- PCP can also cause mydriasis, but the **bloody nasal mucosa** (pointing to intranasal route) and the specific presentation pattern are more consistent with cocaine.
*Tetrahydrocannabinol (THC) intoxication*
- THC intoxication usually causes **conjunctival injection**, **increased appetite**, **euphoria**, and mild **paranoia**, but not typically the severe agitation, hypertension, and marked sympathomimetic features seen here.
- The **bloody nasal mucosa** and **mydriasis** are not typical features of THC use.
*Acute manic episode*
- An acute manic episode can present with **agitation**, **pressured speech**, and **grandiose delusions**, but it would not explain the acute onset in the context of nocturnal clubbing and the specific physical findings such as **tachycardia**, **hypertension**, and **mydriasis** with bloody nasal mucosa, which strongly point to a sympathomimetic substance.
- The **physical signs** suggesting sympathetic activation and **acute context** make illicit stimulant use more likely than a primary psychiatric disorder.
*Thyrotoxicosis*
- **Thyrotoxicosis** can cause **tachycardia**, **agitation**, and anxiety, but it typically has a more gradual onset and presents with **tremor**, **heat intolerance**, **weight loss**, and possibly **exophthalmos**, none of which are mentioned.
- The acute onset in a nightclub setting, **bloody nasal mucosa**, and **marked hypertension** are not consistent with thyrotoxicosis.
Question 888: A 37-year-old male presents to general medical clinic reporting sleeping difficulties. He states that he has daytime sleepiness, having fallen asleep several times while driving his car recently. He sometimes experiences very vivid dreams just before awakening. You ask the patient's wife if she has witnessed any episodes where her husband lost all muscle tone and fell to the ground, and she confirms that he has not had this symptom. The patient notes that this condition runs in his family, and he desperately asks for treatment. You begin him on a first-line medication for this illness, which works by which mechanism of action?
A. Dopamine reuptake inhibition (Correct Answer)
B. Serotonin reuptake inhibition
C. Mu opioid receptor agonism
D. GABA receptor agonism
E. Alpha-2 adrenergic receptor antagonism
Explanation: ***Dopamine reuptake inhibition***
- The patient's symptoms of **excessive daytime sleepiness**, falling asleep while driving, and vivid dreams (hypnagogic hallucinations) are classic for **narcolepsy type 2** (without cataplexy).
- **First-line treatment** for excessive daytime sleepiness in narcolepsy is **modafinil** or **armodafinil**, which work primarily through **dopamine reuptake inhibition** (along with other mechanisms including effects on orexin neurons).
- Alternative first-line agents include **methylphenidate** and **amphetamines**, which also work via **dopamine and norepinephrine reuptake inhibition**.
- These medications promote wakefulness and are supported by AASM and AAN clinical practice guidelines.
*Serotonin reuptake inhibition*
- **SSRIs** and **SNRIs** are sometimes used in narcolepsy but primarily for **cataplexy** management, not daytime sleepiness.
- This patient has **no cataplexy**, making this mechanism less relevant for his primary complaint.
- Not considered first-line for the excessive daytime sleepiness that is this patient's main concern.
*Alpha-2 adrenergic receptor antagonism*
- This is the mechanism of **mirtazapine**, an atypical antidepressant.
- **Not a first-line treatment** for narcolepsy or excessive daytime sleepiness.
- Mirtazapine is actually somewhat sedating and would worsen daytime sleepiness, not improve it.
*Mu opioid receptor agonism*
- This describes traditional opioid analgesics, which are **not used** in narcolepsy treatment.
- Opioids cause sedation and would worsen daytime sleepiness.
- **Sodium oxybate** (used in narcolepsy) is sometimes confused with opioids, but it works primarily through GABA-B receptors, not mu opioid receptors.
*GABA receptor agonism*
- **Sodium oxybate** (gamma-hydroxybutyrate/GHB) works primarily through **GABA-B receptor agonism** and is FDA-approved for narcolepsy.
- However, it is used primarily for **cataplexy** and to improve **nighttime sleep quality**, not as first-line for daytime sleepiness alone.
- While effective, it is typically considered after trials of modafinil/stimulants due to its scheduling restrictions (Schedule III) and side effect profile.
Question 889: A 51-year-old man is bitten by a cottonmouth viper and is successfully treated with sheep hyperimmune Fab antivenom. Three days later, the patient develops an abdominal itchy rash and re-presents to the emergency department for medical care. His medical history is significant for gout, hypertension, hypercholesterolemia, diabetes mellitus type II, and multiple basal cell carcinomas on his face and neck. He currently smokes 1 pack of cigarettes per day, drinks a 6-pack of beer per day, and denies any current illicit drug use. His vital signs include: temperature 40.0°C (104.0°F), blood pressure 126/74 mm Hg, heart rate 111/min, and respiratory rate 23/min. On physical examination, his gait is limited by diffuse arthralgias, lung sounds are clear bilaterally, and he has normal heart sounds. The patient has a pruritic periumbilical serpiginous macular rash that has spread to involve the back, upper trunk, and extremities. Of the following options, which is the next best step in patient management?
A. Glucocorticoid taper with antihistamines (Correct Answer)
B. Plasmapheresis
C. NSAIDs
D. Antihistamines
E. Dialysis
Explanation: ***Glucocorticoid taper with antihistamines***
- The patient's symptoms (rash, arthralgias, fever) developing several days after receiving **sheep hyperimmune Fab antivenom** are classic for **serum sickness**, a type III hypersensitivity reaction.
- Treatment for serum sickness typically involves **oral corticosteroids** (e.g., prednisone) to suppress the immune response and **antihistamines** to manage the pruritus.
*Plasmapheresis*
- This is reserved for **severe cases of serum sickness** when organ damage (e.g., renal failure, severe vasculitis, neurological involvement) is present or when steroid therapy is ineffective.
- The patient's symptoms, while bothersome, do not appear severe enough at this stage to warrant plasmapheresis.
*NSAIDs*
- While NSAIDs can help with arthralgias and fever, they do not address the underlying **immune complex deposition** that causes serum sickness.
- They are insufficient as monotherapy for managing the rash and other systemic symptoms.
*Antihistamines*
- Antihistamines can effectively alleviate the **pruritus** associated with the rash in serum sickness.
- However, they do not treat the **systemic inflammatory response** (fever, arthralgia) or prevent further immune complex deposition, making them inadequate as a primary treatment alone.
*Dialysis*
- Dialysis is indicated for **severe renal failure**, which is not described in this patient's presentation.
- While serum sickness can *rarely* cause glomerulonephritis, there is no evidence here to suggest a need for dialysis.
Question 890: A 34-year-old woman is recovering in the post-operative unit following a laparoscopic procedure for chronic endometriosis. She had initially presented with complaints of painful menstrual cramps that kept her bedridden most of the day. She also mentioned to her gynecologist that she had been diagnosed with endometriosis 4 years ago, and she could not find a medication or alternative therapeutic measure that helped. Her medical history was significant for surgery she had 6 years ago to remove tumors she had above her kidneys, after which she was prescribed hydrocortisone. An hour after the laparoscopic procedure, she calls the nurse because she is having difficulty breathing. The nurse records her vital signs include: blood pressure 85/55 mm Hg, respirations 20/min, and pulse 115/min. The patient suddenly loses consciousness. Intravenous fluids are started immediately. She gains consciousness, but her blood pressure is unchanged. Which of the following is the most likely cause of the hypotension?
A. Bleeding profusely through the surgical site
B. Improper supplementation of steroids (Correct Answer)
C. Infection involving the suture line
D. High doses of anesthetic drugs
E. Loss of fluids during the procedure
Explanation: ***Improper supplementation of steroids***
- The patient's history of **bilateral adrenalectomy (tumors above kidneys)** for which she was prescribed **hydrocortisone** indicates **adrenal insufficiency**. Stressful events like surgery require an increased dose of steroids, and improper supplementation can lead to an **adrenal crisis**.
- The symptoms of **hypotension, tachycardia, and loss of consciousness** are characteristic of an **adrenal crisis (acute adrenal insufficiency)**, which occurs when the body lacks sufficient cortisol during stress.
*Bleeding profusely through the surgical site*
- While **hemorrhage** can cause hypotension and tachycardia, the patient regained consciousness with IV fluids but her **blood pressure remained unchanged**, which is less typical for isolated blood loss if volume is restored without addressing the underlying cause.
- There is no direct mention of visible bleeding, the prompt only states the patient lost consciousness and her blood pressure is unchanged.
*Infection involving the suture line*
- **Surgical site infections** typically manifest several days post-op, presenting with **fever, erythema, and purulent drainage**, not acute hypotension and loss of consciousness an hour after surgery.
- The immediate post-operative timeline and systemic symptoms are not consistent with a localized wound infection as the primary cause of this acute decline.
*High doses of anesthetic drugs*
- Anesthetic drugs can cause **vasodilation and hypotension**. However, their effects are usually transient and would likely resolve more completely with IV fluids, especially an hour after a laparoscopic procedure.
- If it was due to anesthetic drugs, the patient's blood pressure would likely normalize with fluid administration once the effects of the anesthetic began to wear off, which is not the case here.
*Loss of fluids during the procedure*
- **Fluid loss** during surgery can cause hypotension, but intravenous fluids were administered, and the patient regained consciousness.
- If fluid loss were the sole cause, resolving consciousness and maintaining low blood pressure typically indicates the fluid loss was not completely compensated, but the primary cause for the persistent hypotension is not just volume.
