A 51-year-old Caucasian female presents to her primary care provider complaining of intermittent chest pain. She reports that over the past 6 months, she has developed burning chest pain that occurs whenever she exerts herself. The pain decreases when she rests. Her past medical history is notable for type II diabetes mellitus. Her family history is notable for multiple myocardial infarctions in her father and paternal grandmother. She currently takes aspirin and metformin. Her primary care provider starts her on a medication which is indicated given her medical history and current symptoms. However, 10 days later, she presents to the emergency room complaining of weakness and muscle pain. Her plasma creatine kinase level is 250,000 IU/L. This patient was most likely started on a medication that inhibits an enzyme that produces which of the following?
Q752
A 58-year-old woman presents with frequent headaches for the past few months. She says the pain starts randomly and is unrelated to any stimulus. She also says that she has difficulty falling asleep and has had problems concentrating at work for several months. While she occasionally thinks about committing suicide, she denies any suicidal plans. Her appetite is diminished. No significant past medical history. No current medications. There is no family history of depression or psychiatric illness. The physical exam is unremarkable. The thyroid-stimulating hormone (TSH) level is 3.5 uU/mL. The patient is started on amitriptyline and asked to follow-up in 2 weeks. At her follow-up visit, the patient reports slight improvement in her mood and has no more headaches, but she complains of lightheadedness when she rises out of bed in the morning or stands up from her desk at work. Which of the following pharmacological effects of amitriptyline is most likely responsible for her lightheadedness?
Q753
A 61-year-old female is referred to an oncologist for evaluation of a breast lump that she noticed two weeks ago while doing a breast self-examination. Her past medical history is notable for essential hypertension and major depressive disorder for which she takes lisinopril and escitalopram, respectively. Her temperature is 98.6°F (37°C), blood pressure is 120/65 mmHg, pulse is 82/min, and respirations are 18/min. Biopsy of the lesion confirms a diagnosis of invasive ductal carcinoma with metastatic disease in the ipsilateral axillary lymph nodes. The physician starts the patient on a multi-drug chemotherapeutic regimen. The patient successfully undergoes mastectomy and axillary dissection and completes the chemotherapeutic regimen. However, several months after completion of the regimen, the patient presents to the emergency department with dyspnea, chest pain, and palpitations. A chest radiograph demonstrates an enlarged cardiac silhouette. This patient’s current symptoms could have been prevented by administration of which of the following medications?
Q754
A 60-year-old woman with a history of atrial arrhythmia arrives in the emergency department with complaints of tinnitus, headache, visual disturbances, and severe diarrhea. The patient is given oxygen by nasal cannula. ECG leads, pulse oximeter and an automated blood pressure cuff are applied. The patient suddenly faints. Her ECG indicates the presence of a multifocal ventricular tachycardia with continuous change in the QRS electrical axis. Which of the following drugs is most likely responsible for this patient's symptoms?
Q755
A 54-year-old man with a long-standing history of chronic obstructive pulmonary disease (COPD) presents to the clinic for progressive shortness of breath. The patient reports generalized fatigue, distress, and difficulty breathing that is exacerbated with exertion. Physical examination demonstrates clubbing of the fingers, and an echocardiogram shows right ventricular hypertrophy. The patient is placed on a medication for symptom control. One month later, the patient returns for follow up with some improvement in symptoms. Laboratory tests are drawn and shown below:
Serum:
Na+: 137 mEq/L
Cl-: 101 mEq/L
K+: 4.8 mEq/L
HCO3-: 25 mEq/L
BUN: 8.5 mg/dL
Glucose: 117 mg/dL
Creatinine: 1.4 mg/dL
Thyroid-stimulating hormone: 1.8 µU/mL
Ca2+: 9.6 mg/dL
AST: 159 U/L
ALT: 201 U/L
What is the mechanism of action of the likely medication given?
Q756
A 19-year-old boy presents to the emergency department with difficulty breathing, which began 1 hour ago. He has had persistent bronchial asthma since 3 years of age and has been prescribed inhaled fluticasone (400 μg/day) by his pediatrician. He has not taken the preventer inhaler for the last 2 weeks and visited an old house today that had a lot of dust accumulated on the floor. On physical examination, his temperature is 36.8°C (98.4°F), the pulse is 110/min, and the respiratory rate is 24/min. There are no signs of respiratory distress, and chest auscultation reveals bilateral wheezing. Which of the following medications is most likely to provide quick relief?
Q757
A 53-year-old woman presents for a follow-up. She took some blood tests recently for her yearly physical, and her random blood sugar level was found to be 251 mg/dL. She was asked to repeat her blood sugar and come back with the new reports. At that time, her fasting blood sugar level was 130 mg/dL and the postprandial glucose level was 245 mg/dL. Her HbA1c is 8.9%. She has had occasions where she felt light-headed and felt better only after she had something to eat. Her physician starts her on a drug to help her control her sugar levels. He also advised that she should return for routine follow-up labs and repeat HbA1c in 3 months. Which of the following is the mechanism of action of the drug that she was most likely prescribed?
Q758
A 58-year-old woman presents to her primary care physician for a wellness checkup. She recently had a DEXA scan that placed her at 2 standard deviations below the mean for bone density. She is following up today to discuss her results. The patient has a past medical history of asthma, breast cancer, COPD, anxiety, irritable bowel syndrome, endometrial cancer, and depression. She is currently taking clonazepam, albuterol, and fluoxetine. Her temperature is 99.5°F (37.5°C), blood pressure is 127/68 mmHg, pulse is 90/min, respirations are 15/min, and oxygen saturation is 95% on room air. The patient is treated appropriately and sent home. She returns 1 month later for a follow up visit. She has been taking her medications as prescribed. She endorses episodes of feeling febrile/warm which resolve shortly thereafter. Otherwise she is doing well. Which of the following is true of the medication she was most likely started on?
Q759
A 10-year-old girl is brought to the neurologist for management of recently diagnosed seizures. Based on her clinical presentation, the neurologist decides to start a medication that works by blocking thalamic T-type calcium channels. Her parents are cautioned that the medication has a number of side effects including itching, headache, and GI distress. Specifically, they are warned to stop the medication immediately and seek medical attention if they notice skin bullae or sloughing. Which of the following conditions is most likely being treated in this patient?
Q760
A 42-year-old female with a history of systemic lupus erythematosus (SLE) has a 3-year history of daily prednisone (20 mg) use. Due to long-term prednisone use, she is at increased risk for which of the following?
Autonomic/CV Drugs US Medical PG Practice Questions and MCQs
Question 751: A 51-year-old Caucasian female presents to her primary care provider complaining of intermittent chest pain. She reports that over the past 6 months, she has developed burning chest pain that occurs whenever she exerts herself. The pain decreases when she rests. Her past medical history is notable for type II diabetes mellitus. Her family history is notable for multiple myocardial infarctions in her father and paternal grandmother. She currently takes aspirin and metformin. Her primary care provider starts her on a medication which is indicated given her medical history and current symptoms. However, 10 days later, she presents to the emergency room complaining of weakness and muscle pain. Her plasma creatine kinase level is 250,000 IU/L. This patient was most likely started on a medication that inhibits an enzyme that produces which of the following?
A. Farnesyl pyrophosphate
B. Mevalonic acid (Correct Answer)
C. HMG-CoA
D. Lanosterol
E. Squalene
Explanation: ***Mevalonic acid***
- The patient's symptoms (chest pain with exertion, resolving with rest) suggest **angina**, likely due to **atherosclerosis** in the context of **type II diabetes** and a strong family history of myocardial infarctions.
- The medication initiated was likely a **statin**, which inhibits **HMG-CoA reductase**, the enzyme responsible for synthesizing **mevalonic acid** from HMG-CoA, a key step in cholesterol synthesis. The subsequent presentation with **severe myopathy** (weakness, muscle pain, extremely elevated **creatine kinase**) confirms statin-induced rhabdomyolysis.
*Farnesyl pyrophosphate*
- Farnesyl pyrophosphate is an intermediate in the **cholesterol synthesis pathway**, downstream of mevalonic acid.
- While inhibitors could affect cholesterol, the primary target of statins, the most common anti-atherosclerotic drug class in this scenario, is the production of mevalonic acid.
*HMG-CoA*
- **HMG-CoA** is the substrate for **HMG-CoA reductase**, the enzyme inhibited by statins.
- The medication inhibits the *conversion* of HMG-CoA, not HMG-CoA itself.
*Lanosterol*
- **Lanosterol** is a sterol precursor formed later in the **cholesterol biosynthesis pathway**, after mevalonate and squalene.
- Inhibiting the production of lanosterol would occur at a later step than the site of action for statins.
*Squalene*
- **Squalene** is an intermediate in the **cholesterol synthesis pathway**, formed from farnesyl pyrophosphate, downstream of mevalonic acid.
- No commonly used anti-dyslipidemic medications directly inhibit the production of squalene to the same clinical effect seen with statins.
Question 752: A 58-year-old woman presents with frequent headaches for the past few months. She says the pain starts randomly and is unrelated to any stimulus. She also says that she has difficulty falling asleep and has had problems concentrating at work for several months. While she occasionally thinks about committing suicide, she denies any suicidal plans. Her appetite is diminished. No significant past medical history. No current medications. There is no family history of depression or psychiatric illness. The physical exam is unremarkable. The thyroid-stimulating hormone (TSH) level is 3.5 uU/mL. The patient is started on amitriptyline and asked to follow-up in 2 weeks. At her follow-up visit, the patient reports slight improvement in her mood and has no more headaches, but she complains of lightheadedness when she rises out of bed in the morning or stands up from her desk at work. Which of the following pharmacological effects of amitriptyline is most likely responsible for her lightheadedness?
A. Blockage of muscarinic receptors
B. Decreased reuptake of serotonin
C. Blockage of H1 histamine receptors
D. Decreased reuptake of norepinephrine
E. Blockage of α1 adrenergic receptors (Correct Answer)
Explanation: ***Blockage of α1 adrenergic receptors***
- **Orthostatic hypotension**, characterized by lightheadedness upon standing, is a common side effect of tricyclic antidepressants (TCAs) like amitriptyline due to their **α1-adrenergic receptor blocking properties**. This blockade prevents adequate vasoconstriction in response to changes in posture.
- The patient's symptoms of lightheadedness when rising or standing are classic for orthostatic hypotension.
*Blockage of muscarinic receptors*
- This effect leads to **anticholinergic side effects** such as dry mouth, constipation, blurred vision, and urinary retention.
- While amitriptyline has potent anticholinergic effects, they do not directly cause orthostatic hypotension.
*Decreased reuptake of serotonin*
- Amitriptyline is a **tricyclic antidepressant (TCA)** that inhibits reuptake of both serotonin and norepinephrine, and increased serotonin levels contribute to its antidepressant effects.
- However, the cardiovascular side effect of orthostatic hypotension is not primarily mediated by serotonin reuptake inhibition.
*Blockage of H1 histamine receptors*
- Blockade of H1 histamine receptors by amitriptyline contributes to its **sedative effects** and can cause weight gain.
- This effect is not directly responsible for orthostatic hypotension.
*Decreased reuptake of norepinephrine*
- Similar to serotonin, this mechanism contributes to amitriptyline's **antidepressant and pain-modulating effects** by increasing norepinephrine levels in the synaptic cleft.
- While norepinephrine is involved in blood pressure regulation, the specific problem of orthostatic hypotension with TCAs is more directly linked to α1-adrenergic blockade rather than norepinephrine reuptake inhibition itself.
Question 753: A 61-year-old female is referred to an oncologist for evaluation of a breast lump that she noticed two weeks ago while doing a breast self-examination. Her past medical history is notable for essential hypertension and major depressive disorder for which she takes lisinopril and escitalopram, respectively. Her temperature is 98.6°F (37°C), blood pressure is 120/65 mmHg, pulse is 82/min, and respirations are 18/min. Biopsy of the lesion confirms a diagnosis of invasive ductal carcinoma with metastatic disease in the ipsilateral axillary lymph nodes. The physician starts the patient on a multi-drug chemotherapeutic regimen. The patient successfully undergoes mastectomy and axillary dissection and completes the chemotherapeutic regimen. However, several months after completion of the regimen, the patient presents to the emergency department with dyspnea, chest pain, and palpitations. A chest radiograph demonstrates an enlarged cardiac silhouette. This patient’s current symptoms could have been prevented by administration of which of the following medications?
A. Rosuvastatin
B. Cyclophosphamide
C. Dexrazoxane (Correct Answer)
D. Aspirin
E. Vincristine
Explanation: ***Dexrazoxane***:
- This patient likely developed **anthracycline-induced cardiotoxicity** (e.g., from doxorubicin, often used in breast cancer chemotherapy), presenting with **dyspnea, chest pain, palpitations**, and an **enlarged cardiac silhouette** due to heart failure.
- **Dexrazoxane** is a **cardioprotective agent** that can chelate iron, thereby reducing the formation of **free radicals** that cause myocardial damage from anthracyclines.
*Rosuvastatin*:
- **Rosuvastatin** is a **statin** used to lower cholesterol levels and prevent cardiovascular events due to atherosclerosis, which is not the primary cause of her acute symptoms.
- While general **cardiovascular health** is important, rosuvastatin would not specifically prevent anthracycline-induced cardiotoxicity.
*Cyclophosphamide*:
- **Cyclophosphamide** is an **alkylating agent** commonly used in breast cancer treatment, but it is known for causing **hemorrhagic cystitis** and **myelosuppression**, not primary cardiotoxicity that presents acutely as heart failure.
- It is part of the chemotherapeutic regimen that could contribute to the patient's cancer treatment but not a preventative measure for the cardiac side effects described here.
*Aspirin*:
- **Aspirin** is an **antiplatelet agent** used to prevent thrombosis and cardiovascular events like myocardial infarction or stroke, particularly in patients at risk for atherosclerosis.
- It would not prevent the **acute cardiotoxicity** resulting from chemotherapy.
*Vincristine*:
- **Vincristine** is a **microtubule inhibitor** known for significant **neurotoxicity** (e.g., peripheral neuropathy, ileus), but it does not typically cause direct acute cardiotoxicity leading to symptoms of heart failure.
- Its side effect profile is distinct from the cardiac issues described in the patient.
Question 754: A 60-year-old woman with a history of atrial arrhythmia arrives in the emergency department with complaints of tinnitus, headache, visual disturbances, and severe diarrhea. The patient is given oxygen by nasal cannula. ECG leads, pulse oximeter and an automated blood pressure cuff are applied. The patient suddenly faints. Her ECG indicates the presence of a multifocal ventricular tachycardia with continuous change in the QRS electrical axis. Which of the following drugs is most likely responsible for this patient's symptoms?
A. Lidocaine
B. Amiodarone
C. Verapamil
D. Digoxin
E. Quinidine (Correct Answer)
Explanation: ***Quinidine***
- The constellation of **tinnitus**, **headache**, **visual disturbances**, and **diarrhea** along with **multifocal ventricular tachycardia** (specifically **torsades de pointes** due to polymorphic VT with continuous change in QRS electrical axis) is characteristic of **quinidine toxicity** (cinchonism).
- Quinidine is a **Class IA antiarrhythmic** drug known to cause QT prolongation, which can lead to torsades de pointes.
*Lidocaine*
- **Lidocaine** is a **Class IB antiarrhythmic** that primarily affects ventricular arrhythmias and is not typically associated with tinnitus, visual disturbances, or diarrhea at therapeutic doses.
- Its toxicity often manifests as CNS effects like **seizures**, **drowsiness**, or **paresthesias**, and it does not prolong the QT interval or cause torsades de pointes.
*Amiodarone*
- **Amiodarone** is a **Class III antiarrhythmic** drug that can cause a variety of side effects, but **tinnitus** and **severe diarrhea** are not its primary dose-limiting toxicities.
- Its toxicity is more commonly associated with **pulmonary fibrosis**, **thyroid dysfunction**, and **corneal deposits**.
*Verapamil*
- **Verapamil** is a **calcium channel blocker** used for supraventricular arrhythmias and hypertension.
- Its side effects include **bradycardia**, **hypotension**, and **constipation**, but not the specific neurological or gastrointestinal symptoms described, nor does it typically cause torsades de pointes.
*Digoxin*
- **Digoxin toxicity** can cause **arrhythmias** (including ventricular arrhythmias), **visual disturbances** (e.g., yellow-green halos), and **gastrointestinal symptoms** (nausea, vomiting, anorexia).
- However, **tinnitus** and **severe diarrhea** are less typical, and while it *can* cause arrhythmias, **torsades de pointes** (multifocal VT with continuous QRS axis change) is not its characteristic arrhythmia.
Question 755: A 54-year-old man with a long-standing history of chronic obstructive pulmonary disease (COPD) presents to the clinic for progressive shortness of breath. The patient reports generalized fatigue, distress, and difficulty breathing that is exacerbated with exertion. Physical examination demonstrates clubbing of the fingers, and an echocardiogram shows right ventricular hypertrophy. The patient is placed on a medication for symptom control. One month later, the patient returns for follow up with some improvement in symptoms. Laboratory tests are drawn and shown below:
Serum:
Na+: 137 mEq/L
Cl-: 101 mEq/L
K+: 4.8 mEq/L
HCO3-: 25 mEq/L
BUN: 8.5 mg/dL
Glucose: 117 mg/dL
Creatinine: 1.4 mg/dL
Thyroid-stimulating hormone: 1.8 µU/mL
Ca2+: 9.6 mg/dL
AST: 159 U/L
ALT: 201 U/L
What is the mechanism of action of the likely medication given?
A. Prostacyclin with direct vasodilatory effects
B. Beta-2 agonist
C. Inhibition of phosphodiesterase-5 (Correct Answer)
D. Competitive inhibition of muscarinic receptors
E. Competitive inhibition of endothelin-1 receptors
Explanation: ***Inhibition of phosphodiesterase-5***
- The patient's presentation with **COPD**, **progressive shortness of breath**, **clubbing**, and **right ventricular hypertrophy** is highly suggestive of **cor pulmonale**, a type of **pulmonary hypertension** caused by lung disease.
- **Phosphodiesterase-5 (PDE5) inhibitors** (e.g., sildenafil) are used to treat pulmonary hypertension by increasing cGMP levels, leading to **pulmonary vasodilation** and improved symptoms.
*Prostacyclin with direct vasodilatory effects*
- While prostacyclin analogs (e.g., epoprostenol) are potent **pulmonary vasodilators** used in pulmonary hypertension, they are usually reserved for more severe cases or specific etiologies.
- The presented lab values, particularly the elevated AST and ALT, could be a side effect of some medications, but it doesn't specifically point to prostacyclin as the most likely initial treatment given the clinical picture.
*Beta-2 agonist*
- **Beta-2 agonists** (e.g., albuterol) are used to relieve **bronchospasm** in COPD, but they do not directly address the **pulmonary hypertension** component leading to right ventricular hypertrophy and would not be the primary treatment for cor pulmonale.
- While they improve airflow, they don't impact the pulmonary vascular remodeling or pressures.
*Competitive inhibition of muscarinic receptors*
- **Anticholinergic bronchodilators** (e.g., tiotropium) act by blocking muscarinic receptors in the airways, leading to **bronchodilation**.
- Like beta-2 agonists, they target airway obstruction in COPD but do not directly treat the **pulmonary hypertension** and its cardiovascular consequences.
*Competitive inhibition of endothelin-1 receptors*
- **Endothelin receptor antagonists** (e.g., bosentan) are also used in **pulmonary hypertension** to block the vasoconstrictive effects of endothelin-1.
- While a plausible treatment for pulmonary hypertension, **PDE5 inhibitors** are often a first-line oral therapy, and the elevated liver enzymes (AST, ALT) could be a concern with some endothelin receptor antagonists, making it less likely as the initial symptomatic treatment.
Question 756: A 19-year-old boy presents to the emergency department with difficulty breathing, which began 1 hour ago. He has had persistent bronchial asthma since 3 years of age and has been prescribed inhaled fluticasone (400 μg/day) by his pediatrician. He has not taken the preventer inhaler for the last 2 weeks and visited an old house today that had a lot of dust accumulated on the floor. On physical examination, his temperature is 36.8°C (98.4°F), the pulse is 110/min, and the respiratory rate is 24/min. There are no signs of respiratory distress, and chest auscultation reveals bilateral wheezing. Which of the following medications is most likely to provide quick relief?
A. Inhaled cromolyn
B. Inhaled albuterol (Correct Answer)
C. Inhaled salmeterol
D. Oral montelukast
E. Inhaled fluticasone
Explanation: ***Inhaled albuterol***
- **Albuterol** is a **short-acting beta-agonist (SABA)** that provides rapid bronchodilation by relaxing airway smooth muscles.
- Its quick onset of action makes it ideal for immediate relief of **acute asthma symptoms** like wheezing and shortness of breath.
*Inhaled cromolyn*
- **Cromolyn** is a **mast cell stabilizer** that works by preventing the release of inflammatory mediators.
- It is a **preventive medication** for asthma and does not provide quick relief for acute exacerbations.
*Inhaled salmeterol*
- **Salmeterol** is a **long-acting beta-agonist (LABA)** used for **long-term control** of asthma.
- It has a slower onset of action and is not appropriate for **acute symptom relief**.
*Oral montelukast*
- **Montelukast** is a **leukotriene receptor antagonist** used for **long-term asthma control** and prevention of exercise-induced bronchoconstriction.
- It does not provide immediate relief for an **acute asthma attack**.
*Inhaled fluticasone*
- **Fluticasone** is an **inhaled corticosteroid (ICS)** used as a **preventer medication** to reduce airway inflammation in asthma.
- Its therapeutic effects are not immediate, and it is ineffective for **acute symptom management**.
Question 757: A 53-year-old woman presents for a follow-up. She took some blood tests recently for her yearly physical, and her random blood sugar level was found to be 251 mg/dL. She was asked to repeat her blood sugar and come back with the new reports. At that time, her fasting blood sugar level was 130 mg/dL and the postprandial glucose level was 245 mg/dL. Her HbA1c is 8.9%. She has had occasions where she felt light-headed and felt better only after she had something to eat. Her physician starts her on a drug to help her control her sugar levels. He also advised that she should return for routine follow-up labs and repeat HbA1c in 3 months. Which of the following is the mechanism of action of the drug that she was most likely prescribed?
A. Decreases the secretion of glucagon.
B. Stimulates the release of insulin from the pancreas.
C. Inhibit alpha-glucosidase in the intestines.
D. Acts as an agonist at the peroxisome proliferator-activated receptor-Ƴ.
E. Increases the uptake of glucose and reduces peripheral insulin resistance. (Correct Answer)
Explanation: ***Increases the uptake of glucose and reduces peripheral insulin resistance.***
- The patient's presentation with **elevated random, fasting, and postprandial blood sugar levels**, along with an **HbA1c of 8.9%**, is highly indicative of **Type 2 Diabetes Mellitus**. **Metformin**, which works by increasing glucose uptake and reducing insulin resistance, is the **first-line treatment** for this condition.
- Metformin primarily acts in the **liver** to decrease **hepatic glucose production**, and in **peripheral tissues** (muscle and fat) to improve **insulin sensitivity** and glucose utilization.
*Decreases the secretion of glucagon.*
- This is the mechanism of action for drugs like **GLP-1 receptor agonists** (e.g., liraglutide) and **DPP-4 inhibitors** (e.g., sitagliptin), which are typically **second-line agents** or used in combination therapy.
- While these drugs are effective in diabetes management, they are generally not the initial choice for newly diagnosed Type 2 diabetes due to the established efficacy and safety profile of metformin.
*Stimulates the release of insulin from the pancreas.*
- This mechanism describes **sulfonylureas** (e.g., glipizide) and **meglitinides** (e.g., repaglinide).
- These drugs carry a higher risk of **hypoglycemia** and weight gain compared to metformin, making them less favorable as initial monotherapy in most patients.
*Inhibit alpha-glucosidase in the intestines.*
- This is the mechanism of **alpha-glucosidase inhibitors** like **acarbose** and **miglitol**.
- These drugs delay carbohydrate absorption, primarily targeting **postprandial hyperglycemia**, but are not typically used as first-line monotherapy due to their modest efficacy and common gastrointestinal side effects.
*Acts as an agonist at the peroxisome proliferator-activated receptor-Ƴ.*
- This describes the mechanism of **thiazolidinediones** (TZDs) like **pioglitazone** and **rosiglitazone**.
- While TZDs improve insulin sensitivity, they are associated with side effects such as **fluid retention, heart failure**, and **bone fractures**, making them less preferred as initial therapy compared to metformin.
Question 758: A 58-year-old woman presents to her primary care physician for a wellness checkup. She recently had a DEXA scan that placed her at 2 standard deviations below the mean for bone density. She is following up today to discuss her results. The patient has a past medical history of asthma, breast cancer, COPD, anxiety, irritable bowel syndrome, endometrial cancer, and depression. She is currently taking clonazepam, albuterol, and fluoxetine. Her temperature is 99.5°F (37.5°C), blood pressure is 127/68 mmHg, pulse is 90/min, respirations are 15/min, and oxygen saturation is 95% on room air. The patient is treated appropriately and sent home. She returns 1 month later for a follow up visit. She has been taking her medications as prescribed. She endorses episodes of feeling febrile/warm which resolve shortly thereafter. Otherwise she is doing well. Which of the following is true of the medication she was most likely started on?
A. Parathyroid hormone analogue
B. Induces osteoclast apoptosis
C. Estrogen receptor antagonist in the uterus (Correct Answer)
D. Mineral replacement
E. Estrogen receptor agonist in the uterus
Explanation: ***Estrogen receptor antagonist in the uterus***
- Given her history of **breast cancer** and **endometrial cancer**, the patient was likely started on **raloxifene** for osteoporosis. Raloxifene acts as an **estrogen receptor antagonist** in uterine tissue, which is beneficial in preventing endometrial proliferation and cancer recurrence.
- The "feeling febrile/warm" episodes she describes are consistent with **hot flashes**, a common side effect of raloxifene due to its **estrogen receptor antagonism** in other tissues.
*Parathyroid hormone analogue*
- **Teriparatide**, a parathyroid hormone analogue, is an anabolic agent that stimulates bone formation. However, it is typically reserved for **severe osteoporosis** or patients who have failed other therapies.
- While effective, teriparatide is administered daily via injection, and its side effects profile does not perfectly align with the patient's symptoms of feeling febrile/warm.
*Induces osteoclast apoptosis*
- This describes the mechanism of action of **bisphosphonates** (e.g., alendronate, zoledronic acid), which are common first-line treatments for osteoporosis.
- However, bisphosphonates do not typically cause symptoms like "feeling febrile/warm" (hot flashes), which points away from this class of medication in this clinical scenario.
*Mineral replacement*
- This refers to **calcium and vitamin D supplementation**, which are foundational but usually adjunct therapies for osteoporosis, not the primary treatment that would cause hot flashes.
- While essential for bone health, calcium and vitamin D alone would not be sufficient treatment for osteoporosis identified by a DEXA scan 2 standard deviations below the mean, nor would they cause febrile sensations.
*Estrogen receptor agonist in the uterus*
- This describes **estrogen therapy (ERT)** or some forms of **hormone replacement therapy (HRT)**. While effective for osteoporosis, ERT is **contraindicated** in patients with a history of **breast cancer** and **endometrial cancer** due to the increased risk of recurrence.
- Additionally, estrogen receptor agonists would typically *alleviate* hot flashes, rather than cause them, which contradicts the patient's reported symptoms.
Question 759: A 10-year-old girl is brought to the neurologist for management of recently diagnosed seizures. Based on her clinical presentation, the neurologist decides to start a medication that works by blocking thalamic T-type calcium channels. Her parents are cautioned that the medication has a number of side effects including itching, headache, and GI distress. Specifically, they are warned to stop the medication immediately and seek medical attention if they notice skin bullae or sloughing. Which of the following conditions is most likely being treated in this patient?
A. Absence seizures (Correct Answer)
B. Simple seizures
C. Complex seizures
D. Status epilepticus
E. Tonic-clonic seizures
Explanation: ***Absence seizures***
- The medication described works by blocking **thalamic T-type calcium channels**, which is the specific mechanism of **ethosuximide**, the first-line treatment for absence seizures.
- Ethosuximide selectively targets the thalamic circuits involved in the 3-Hz spike-and-wave pattern characteristic of absence seizures.
- While the question mentions serious skin reactions (bullae/sloughing suggestive of **Stevens-Johnson syndrome**), this is more commonly associated with other antiepileptics like **lamotrigine** or **carbamazepine** rather than ethosuximide specifically. However, the T-type calcium channel mechanism definitively points to absence seizure treatment.
- Common side effects of ethosuximide include **GI distress, headache**, and rarely blood dyscrasias.
*Simple seizures*
- **Simple partial seizures** involve focal brain activity without loss of consciousness and do not primarily involve thalamic T-type calcium channels.
- These are typically treated with drugs like **carbamazepine**, **phenytoin**, or **lamotrigine**, which work through sodium channel blockade or other mechanisms.
*Complex seizures*
- **Complex partial seizures** originate focally with impaired consciousness, involving limbic or temporal structures rather than thalamic circuits.
- Treatment includes **carbamazepine**, **levetiracetam**, or **valproic acid**, which have different mechanisms than T-type calcium channel blockade.
*Status epilepticus*
- **Status epilepticus** is a life-threatening emergency requiring immediate intervention with **benzodiazepines** (lorazepam, diazepam) followed by other IV antiepileptics.
- This condition requires rapid-acting GABAergic agents, not drugs targeting T-type calcium channels.
*Tonic-clonic seizures*
- **Generalized tonic-clonic seizures** involve widespread cortical discharge and are treated with broad-spectrum agents like **valproic acid**, **levetiracetam**, or **lamotrigine**.
- While some antiepileptics may affect calcium channels, selective T-type calcium channel blockade is not the primary mechanism for treating tonic-clonic seizures.
Question 760: A 42-year-old female with a history of systemic lupus erythematosus (SLE) has a 3-year history of daily prednisone (20 mg) use. Due to long-term prednisone use, she is at increased risk for which of the following?
A. Systolic hypertension
B. Weight loss
C. Pathologic fractures (Correct Answer)
D. Hair loss
E. Pancreatic insufficiency
Explanation: ***Pathologic fractures***
- Chronic systemic **corticosteroid use**, like prednisone, can lead to **osteoporosis** by increasing bone resorption and decreasing bone formation.
- This weakens bones, making them susceptible to **pathologic fractures** even with minimal trauma.
*Systolic hypertension*
- While corticosteroids can cause **hypertension**, they typically lead to an increase in both **systolic and diastolic pressures**, not isolated systolic hypertension.
- The primary mechanism involves increased fluid retention and vasoconstriction.
*Weight loss*
- Long-term prednisone use is commonly associated with **weight gain** due to increased appetite, fluid retention, and altered fat distribution (e.g., central obesity).
- It does not typically cause weight loss.
*Hair loss*
- **Hair loss** can be a symptom of SLE itself, but it is not a direct or common side effect of prednisone therapy.
- Corticosteroids can sometimes cause hair to grow thicker or change texture.
*Pancreatic insufficiency*
- Although corticosteroids can cause **pancreatitis** in rare cases, they do not typically lead to chronic **pancreatic insufficiency**.
- Pancreatic insufficiency is more commonly associated with conditions like cystic fibrosis or chronic alcohol abuse.
