A 57-year-old otherwise healthy male presents to his primary care physician for a check-up. He has no complaints. His blood pressure at the previous visit was 160/95. The patient did not wish to be on any medications and at the time attempted to manage his blood pressure with diet and exercise. On repeat measurement of blood pressure today, the reading is 163/92. His physician decides to prescribe a medication which the patient agrees to take. The patient calls his physician 6 days later complaining of a persistent cough, but otherwise states that his BP was measured as 145/85 at a local pharmacy. Which of the following is a contraindication to this medication?
Q102
A 65-year-old man with a history of hypertension visits your office. His blood pressure on physical examination is found to be 150/90. You prescribe him metoprolol. Which of the following do you expect to occur as a result of the drug?
Q103
A 56-year-old man with hypertension comes to the physician for a follow-up examination. His blood pressure is 165/92 mm Hg on the left arm and 162/90 mm Hg on the right arm. He reports that he is compliant with his medication and exercise regimen. The physician adds a drug to his antihypertensive medication regimen. This drug increases serum renin, angiotensin I, and angiotensin II levels, and decreases serum aldosterone levels, without affecting bradykinin levels. Which of the following drugs was most likely added to this patient's medication regimen?
Q104
A 50-year-old woman comes to the physician because of intermittent pain and numbness in her right hand for 6 weeks. She has a pins-and-needles sensation that worsens at night and is relieved when she shakes her hand. She also has episodic left knee pain throughout the day. She has a history of hypertension controlled with lisinopril. She takes over-the-counter medications for constipation. Her BMI is 35 kg/m2. Her mother has a history of rheumatoid arthritis. She looks fatigued. Her pulse is 57/min and blood pressure is 120/75 mm Hg. On physical examination, there is normal range of motion in the wrists and digits. Sensation is decreased to light touch in the thumb and index finger. There is no thenar muscle atrophy. Deep tendon reflexes are 1+ and there is mild edema in the legs. Which of the following treatments is most likely to benefit the patient?
Q105
A 45-year-old man comes to the physician for a follow-up examination after being diagnosed with hypertension 6 months ago. He has cut salt out of his diet and started exercising regularly, but home blood pressure measurements continue to be elevated. His blood pressure is 160/85 mm Hg. An antihypertensive medication is prescribed that decreases blood pressure by decreasing the transmembrane calcium current across vascular smooth muscle cells. Side effects include peripheral edema and flushing. Which of the following best describes why this drug does not affect skeletal muscle contraction?
Q106
A 47-year-old farmer presents to his primary care physician for the first time appointment. The patient has never seen a doctor and states that he is in good health. He has worked as a farmer for the past 30 years and has no complaints. His temperature is 98.9°F (37.2°C), blood pressure is 197/118 mmHg, pulse is 90/min, respirations are 14/min, and oxygen saturation is 98% on room air. Physical exam is notable for an obese man in no current distress. Laboratory values are seen below.
Serum:
Na+: 139 mEq/L
Cl-: 101 mEq/L
K+: 5.2 mEq/L
HCO3-: 25 mEq/L
BUN: 34 mg/dL
Glucose: 179 mg/dL
Creatinine: 2.1 mg/dL
Ca2+: 10.2 mg/dL
Which of the following is the best management of this patient's blood pressure?
Q107
A 45-year-old man presents with a chief complaint of pain in the great toe. He has a history of gout, which is under control. He was diagnosed with diabetes 5 years ago and is currently taking metformin. He was recently diagnosed with hypertension and was placed on a hypertensive drug. He is a non-smoker and does not abuse alcohol. The family history is significant for ischemic heart disease in his father. His current blood pressure is 136/84 mm Hg and the pulse is 78/min. The physical examination did not reveal any abnormalities. He uses over-the-counter multivitamin supplements. Which of the following drugs could have resulted in these symptoms?
Q108
A patient presents to the clinic with symptoms of dizziness on standing up. He says it started soon after he was diagnosed with hypertension and started taking treatment for it. He has no other medical history. The physician decides to switch to another antihypertensive that does not cause orthostatic hypotension. Which of the following should be the drug of choice for this patient?
Q109
A 27-year-old G1P0 woman at 25 weeks estimated gestational age presents with a blood pressure of 188/99 mm Hg during a routine prenatal visit. She has no symptoms, except for a mild headache. The patient's heart rate is 78/min. An injectable antihypertensive along with a beta-blocker is administered, and her blood pressure returns to normal within a couple of hours. She is sent home with advice to continue the beta-blocker. The patient returns after a couple of weeks with joint pain in both of her knees and fatigue. A blood test for anti-histone antibodies is positive. Which of the following is the mechanism of action of the intravenous antihypertensive medication most likely used in this patient?
Q110
A 52-year-old woman with type 2 diabetes, treated with metformin, presents for a routine physical examination. Her vital signs are: pulse 85/min, respiratory rate 15/min, blood pressure 162/96 mm Hg, and temperature 37.0°C (98.6°F). A first-line antihypertensive drug is initiated. Which of the following is the most likely effect of this medication on the following parameters?
Parameters (in order):
1. 24-hour urine sodium
2. Aldosterone
3. Angiotensin II
4. Peripheral vascular resistance
5. Renin
Antihypertensives US Medical PG Practice Questions and MCQs
Question 101: A 57-year-old otherwise healthy male presents to his primary care physician for a check-up. He has no complaints. His blood pressure at the previous visit was 160/95. The patient did not wish to be on any medications and at the time attempted to manage his blood pressure with diet and exercise. On repeat measurement of blood pressure today, the reading is 163/92. His physician decides to prescribe a medication which the patient agrees to take. The patient calls his physician 6 days later complaining of a persistent cough, but otherwise states that his BP was measured as 145/85 at a local pharmacy. Which of the following is a contraindication to this medication?
A. Congestive heart failure
B. Black race
C. Bilateral renal artery stenosis (Correct Answer)
D. Chronic obstructive pulmonary disease
E. Gout
Explanation: ***Bilateral renal artery stenosis***
- The patient's developing **cough** after starting a new antihypertensive suggests he was likely prescribed an **ACE inhibitor**.
- **Bilateral renal artery stenosis** is a strong contraindication for ACE inhibitors due to the risk of precipitating **acute kidney injury**, as these medications rely on efferent arteriolar vasodilation to maintain renal perfusion when there's reduced afferent flow.
*Congestive heart failure*
- **ACE inhibitors** are often a **first-line treatment** for heart failure due to their ability to improve cardiac remodeling and reduce mortality.
- They are used to prevent ventricular remodeling and reduce afterload, making this an indication, not a contraindication.
*Black race*
- While ACE inhibitors may be **less effective as monotherapy** in black patients, they are not contraindicated and can be effectively used in combination with other antihypertensives, such as **thiazide diuretics** or **calcium channel blockers**.
- **African Americans** often respond better to calcium channel blockers and diuretics for hypertension but ACE inhibitors are not absolutely contraindicated.
*Chronic obstructive pulmonary disease*
- **ACE inhibitors** are **not contraindicated** in COPD, as they do not affect bronchial smooth muscle tone.
- **Beta-blockers**, not ACE inhibitors, are typically avoided or used with caution in patients with reactive airway diseases like asthma or severe COPD.
*Gout*
- **ACE inhibitors** do not significantly impact **uric acid levels** and are generally safe for use in patients with gout.
- In contrast, **thiazide diuretics** can increase uric acid levels and worsen gout, but this is not the medication indicated by the patient's cough.
Question 102: A 65-year-old man with a history of hypertension visits your office. His blood pressure on physical examination is found to be 150/90. You prescribe him metoprolol. Which of the following do you expect to occur as a result of the drug?
A. Increased serum renin levels as a consequence of ß2 receptor antagonism
B. Decreased PR interval on EKG
C. Increased serum renin levels as a consequence of ß1 receptor antagonism
D. Decreased serum renin levels as a consequence of ß2 antagonism
E. Decreased serum renin levels as a consequence of ß1 receptor antagonism (Correct Answer)
Explanation: ***Decreased serum renin levels as a consequence of ß1 receptor antagonism***
- Metoprolol is a **selective beta-1 blocker**, primarily acting on beta-1 adrenergic receptors in the heart and kidneys.
- Antagonism of **renal beta-1 receptors** reduces **renin secretion** from the juxtaglomerular cells, leading to decreased angiotensin II and aldosterone levels, and ultimately lower blood pressure.
*Increased serum renin levels as a consequence of ß2 receptor antagonism*
- This is incorrect because beta-2 receptor stimulation generally leads to some **renin release**, and their antagonism would not inherently cause an increase in renin.
- Moreover, metoprolol primarily antagonizes **beta-1 receptors**, not beta-2 receptors, at typical therapeutic doses.
*Decreased PR interval on EKG*
- Beta-blockers like metoprolol decrease the **sinoatrial node firing rate** and **atrioventricular (AV) nodal conduction velocity**.
- This effect would typically **increase** (prolong) the **PR interval** on an EKG, not decrease it.
*Increased serum renin levels as a consequence of ß1 receptor antagonism*
- This is incorrect because **beta-1 receptor stimulation** *increases* renin release, so **beta-1 receptor antagonism** would *decrease* renin levels.
- The direct effect of beta-1 blockade in the kidneys is to reduce renin secretion.
*Decreased serum renin levels as a consequence of ß2 antagonism*
- This is incorrect. While some beta-2 receptors are present in the kidneys, their role in renin release is less prominent than **beta-1 receptors**.
- The primary mechanism by which metoprolol reduces renin is through its **beta-1 receptor antagonism**.
Question 103: A 56-year-old man with hypertension comes to the physician for a follow-up examination. His blood pressure is 165/92 mm Hg on the left arm and 162/90 mm Hg on the right arm. He reports that he is compliant with his medication and exercise regimen. The physician adds a drug to his antihypertensive medication regimen. This drug increases serum renin, angiotensin I, and angiotensin II levels, and decreases serum aldosterone levels, without affecting bradykinin levels. Which of the following drugs was most likely added to this patient's medication regimen?
A. Lisinopril
B. Aliskiren
C. Triamterene
D. Metoprolol
E. Candesartan (Correct Answer)
Explanation: ***Candesartan***
- **Candesartan** is an **Angiotensin Receptor Blocker (ARB)**. ARBs block the AT1 receptor, preventing angiotensin II from exerting its effects, including vasoconstriction and aldosterone release.
- By blocking the AT1 receptor, ARBs lead to a compensatory increase in renin, angiotensin I, and angiotensin II levels due to the interrupted negative feedback loop, while lowering aldosterone; they do not affect bradykinin metabolism.
*Lisinopril*
- **Lisinopril** is an **ACE inhibitor**, which prevents the conversion of angiotensin I to angiotensin II, leading to decreased angiotensin II and aldosterone levels.
- ACE inhibitors also inhibit the breakdown of **bradykinin**, leading to increased bradykinin levels, which is a key differentiating feature not described in the question.
*Aliskiren*
- **Aliskiren** is a **direct renin inhibitor**; it directly inhibits renin, thus decreasing the production of angiotensin I, angiotensin II, and subsequently aldosterone.
- This drug would decrease, not increase, serum renin, angiotensin I, and angiotensin II levels.
*Triamterene*
- **Triamterene** is a **potassium-sparing diuretic** that blocks sodium channels in the collecting duct, leading to increased sodium excretion and potassium retention.
- It does not directly affect the **renin-angiotensin-aldosterone system (RAAS)** in the manner described, nor does it affect bradykinin levels.
*Metoprolol*
- **Metoprolol** is a **beta-blocker** that primarily reduces heart rate, cardiac output, and renin release from the kidneys.
- It would therefore tend to *decrease* renin activity, and consequently lower angiotensin II and aldosterone, which contradicts the described hormonal changes.
Question 104: A 50-year-old woman comes to the physician because of intermittent pain and numbness in her right hand for 6 weeks. She has a pins-and-needles sensation that worsens at night and is relieved when she shakes her hand. She also has episodic left knee pain throughout the day. She has a history of hypertension controlled with lisinopril. She takes over-the-counter medications for constipation. Her BMI is 35 kg/m2. Her mother has a history of rheumatoid arthritis. She looks fatigued. Her pulse is 57/min and blood pressure is 120/75 mm Hg. On physical examination, there is normal range of motion in the wrists and digits. Sensation is decreased to light touch in the thumb and index finger. There is no thenar muscle atrophy. Deep tendon reflexes are 1+ and there is mild edema in the legs. Which of the following treatments is most likely to benefit the patient?
A. Surgical decompression
B. Oral prednisone
C. Methotrexate
D. L-thyroxine (Correct Answer)
E. Ibuprofen
Explanation: ***L-thyroxine***
- The patient's symptoms of **fatigue** and **bradycardia (pulse 57/min)**, along with a high BMI and leg edema, suggest **hypothyroidism** as a contributing factor to her carpal tunnel syndrome. Subclinical hypothyroidism is a common cause of neuropathy and can be easily treated with thyroid hormone replacement.
- **L-thyroxine** replacement would address the underlying metabolic derangement, potentially resolving the nerve compression symptoms and improving overall systemic function.
*Surgical decompression*
- While recommended for severe carpal tunnel syndrome, the absence of **thenar atrophy** and **normal range of motion** suggests her condition is not yet severe enough to warrant immediate surgery, especially without addressing potential underlying causes.
- This is typically reserved for cases unresponsive to conservative management or with objective signs of severe nerve damage.
*Oral prednisone*
- **Corticosteroids** can provide short-term relief for carpal tunnel syndrome by reducing inflammation, but they do not address the underlying cause and are not a long-term solution.
- Their use is generally reserved for acute flares or as a temporary measure, not as primary treatment for chronic symptoms with a likely systemic cause.
*Methotrexate*
- This medication is a **disease-modifying antirheumatic drug (DMARD)** primarily used for autoimmune conditions like **rheumatoid arthritis** or psoriatic arthritis.
- The patient's symptoms are more consistent with carpal tunnel syndrome exacerbated by an underlying metabolic issue, rather than an inflammatory arthropathy, making methotrexate inappropriate.
*Ibuprofen*
- **NSAIDs** like ibuprofen can help manage pain and inflammation but do not address the underlying **nerve compression** or the potential systemic cause (hypothyroidism) of her carpal tunnel syndrome.
- It would offer only symptomatic relief without treating the root problem, and chronic use can have side effects.
Question 105: A 45-year-old man comes to the physician for a follow-up examination after being diagnosed with hypertension 6 months ago. He has cut salt out of his diet and started exercising regularly, but home blood pressure measurements continue to be elevated. His blood pressure is 160/85 mm Hg. An antihypertensive medication is prescribed that decreases blood pressure by decreasing the transmembrane calcium current across vascular smooth muscle cells. Side effects include peripheral edema and flushing. Which of the following best describes why this drug does not affect skeletal muscle contraction?
A. Skeletal muscle contraction occurs independently of extracellular calcium influx (Correct Answer)
B. Skeletal muscle preferentially expresses N-type and P-type calcium channels
C. Skeletal muscle calcium channels do not undergo conformational change when bound to this drug
D. Skeletal muscle ryanodine receptor activation occurs independently of membrane depolarization
E. Skeletal muscle lacks voltage-gated L-type calcium channels
Explanation: ***Skeletal muscle contraction occurs independently of extracellular calcium influx***
- Skeletal muscle contraction is primarily initiated by the release of **intracellular calcium** from the **sarcoplasmic reticulum** via **ryanodine receptors (RyRs)**.
- While L-type calcium channels (dihydropyridine receptors, DHPRs) are present in skeletal muscle, their main role is to act as **voltage sensors** that mechanically activate RyRs, rather than to provide significant calcium influx for contraction.
*Skeletal muscle preferentially expresses N-type and P-type calcium channels*
- **N-type** and **P/Q-type calcium channels** are primarily found in **neurons** at presynaptic terminals, where they mediate neurotransmitter release.
- While skeletal muscle does have calcium channels, the primary voltage-gated channels involved in excitation-contraction coupling are **L-type calcium channels (DHPRs)**, not N or P-type.
*Skeletal muscle calcium channels do not undergo conformational change when bound to this drug*
- This statement is incorrect because the drug class in question, **dihydropyridine calcium channel blockers**, specifically acts on L-type calcium channels (DHPRs).
- While the drug may bind to skeletal muscle DHPRs, the functional consequence is less significant because **skeletal muscle contraction** is not highly dependent on extracellular calcium influx through these channels.
*Skeletal muscle ryanodine receptor activation occurs independently of membrane depolarization*
- This statement is incorrect. **Skeletal muscle ryanodine receptors (RyRs)** are directly activated by a **conformational change** in the adjacent **dihydropyridine receptors (DHPRs)** in response to **membrane depolarization**.
- This mechanical coupling is triggered by the action potential spreading along the muscle fiber, leading to calcium release.
*Skeletal muscle lacks voltage-gated L-type calcium channels*
- This statement is incorrect. Skeletal muscle actually contains **voltage-gated L-type calcium channels (DHPRs)** in its T-tubule membranes.
- However, in skeletal muscle, these channels primarily function as **voltage sensors** that mechanically trigger the release of calcium from the sarcoplasmic reticulum, rather than allowing significant calcium influx to directly initiate contraction.
Question 106: A 47-year-old farmer presents to his primary care physician for the first time appointment. The patient has never seen a doctor and states that he is in good health. He has worked as a farmer for the past 30 years and has no complaints. His temperature is 98.9°F (37.2°C), blood pressure is 197/118 mmHg, pulse is 90/min, respirations are 14/min, and oxygen saturation is 98% on room air. Physical exam is notable for an obese man in no current distress. Laboratory values are seen below.
Serum:
Na+: 139 mEq/L
Cl-: 101 mEq/L
K+: 5.2 mEq/L
HCO3-: 25 mEq/L
BUN: 34 mg/dL
Glucose: 179 mg/dL
Creatinine: 2.1 mg/dL
Ca2+: 10.2 mg/dL
Which of the following is the best management of this patient's blood pressure?
A. Lisinopril
B. Hydrochlorothiazide (Correct Answer)
C. Nicardipine
D. Carvedilol
E. Metoprolol
Explanation: ***Hydrochlorothiazide***
- This patient has **severe hypertension with renal impairment** (Cr 2.1 mg/dL) and **hyperkalemia** (K+ 5.2 mEq/L), making a **thiazide diuretic** the best initial choice.
- **Thiazides lower potassium levels**, addressing the hyperkalemia that contraindicates ACE inhibitors in this patient.
- **Effective for hypertension** at this level of renal function (creatinine < 2.5 mg/dL) and recommended as **first-line therapy** per ACC/AHA guidelines.
- While thiazides can worsen glucose slightly, this is a **minor concern compared to the risk of worsening hyperkalemia** with ACE inhibitors.
*Lisinopril*
- Although **ACE inhibitors** have **renoprotective effects** and are beneficial in diabetic nephropathy, they are **relatively contraindicated** in this patient due to **existing hyperkalemia** (K+ 5.2 mEq/L).
- ACE inhibitors **increase potassium** by reducing aldosterone secretion, risking **dangerous hyperkalemia** (potentially > 6.0 mEq/L).
- In patients with **renal impairment and hyperkalemia**, ACE inhibitors can precipitate **acute kidney injury** and life-threatening arrhythmias.
- The hyperkalemia must be addressed first before considering ACE inhibitor therapy.
*Nicardipine*
- **Nicardipine** is a **dihydropyridine calcium channel blocker** used primarily for **hypertensive emergencies** requiring rapid IV blood pressure reduction.
- This patient has **severe asymptomatic hypertension** without acute end-organ damage (no acute distress, stable vitals), making this **chronic hypertension** requiring oral management, not an emergency.
*Carvedilol*
- **Carvedilol** is a **non-selective beta-blocker with alpha-blocking activity** used for hypertension with co-existing **heart failure** or **post-MI**.
- No evidence of heart failure or coronary disease in this presentation, making it **not first-line**.
- Beta-blockers can **mask hypoglycemic symptoms** in diabetic patients and may worsen **insulin resistance**.
*Metoprolol*
- **Metoprolol** is a **selective beta-1 blocker** that can be used for hypertension but is **not preferred first-line** in this clinical scenario.
- Like other beta-blockers, it can **worsen glucose control** and **mask hypoglycemia** in diabetic patients.
- Does not address the **hyperkalemia** or provide the blood pressure efficacy needed in this patient with severe hypertension and metabolic concerns.
Question 107: A 45-year-old man presents with a chief complaint of pain in the great toe. He has a history of gout, which is under control. He was diagnosed with diabetes 5 years ago and is currently taking metformin. He was recently diagnosed with hypertension and was placed on a hypertensive drug. He is a non-smoker and does not abuse alcohol. The family history is significant for ischemic heart disease in his father. His current blood pressure is 136/84 mm Hg and the pulse is 78/min. The physical examination did not reveal any abnormalities. He uses over-the-counter multivitamin supplements. Which of the following drugs could have resulted in these symptoms?
A. Angiotensin-converting enzyme (ACE) inhibitors
B. Angiotensin II receptor blockers (ARBs)
C. Thiazide diuretics (Correct Answer)
D. Calcium channel blockers (CCBs)
E. Beta-blockers
Explanation: ***Thiazide diuretics***
- **Thiazide diuretics** can increase serum uric acid levels by reducing its renal excretion, thereby precipitating a **gout flare**, especially in individuals with a pre-existing history of gout.
- This patient's history of gout and recent initiation of a hypertensive drug strongly suggest that a thiazide diuretic is the most likely cause of his current symptoms.
*Angiotensin-converting enzyme (ACE) inhibitors*
- **ACE inhibitors** are generally favorable for patients with gout as they tend to **lower uric acid levels** or have no significant impact on them.
- They are often preferred for hypertension in patients with diabetes due to their **renal protective effects**.
*Angiotensin II receptor blockers (ARBs)*
- Some **ARBs**, particularly **losartan**, have a **uricosuric effect**, meaning they can lower uric acid levels and are thus beneficial for patients with gout.
- ARBs, in general, are not associated with increasing uric acid or triggering gout flares.
*Calcium channel blockers (CCBs)*
- **CCBs** are considered **neutral or beneficial** in terms of uric acid metabolism and gout.
- They do not typically cause hyperuricemia or gout flares.
*Beta-blockers*
- **Beta-blockers** are generally considered to have a **neutral effect** on uric acid levels.
- They are not known to precipitate gout attacks.
Question 108: A patient presents to the clinic with symptoms of dizziness on standing up. He says it started soon after he was diagnosed with hypertension and started taking treatment for it. He has no other medical history. The physician decides to switch to another antihypertensive that does not cause orthostatic hypotension. Which of the following should be the drug of choice for this patient?
A. Clonidine
B. Methyldopa
C. Enalapril
D. Amlodipine (Correct Answer)
E. Propranolol
Explanation: ***Amlodipine***
- Amlodipine is a **dihydropyridine calcium channel blocker** that causes **peripheral vasodilation** but does **NOT typically cause orthostatic hypotension** because it maintains blood pressure across postural changes.
- Unlike centrally acting agents, amlodipine does **not impair baroreceptor reflexes** or reduce sympathetic tone, allowing normal cardiovascular compensation when standing.
- It is an excellent choice for patients who experienced orthostatic hypotension with other antihypertensives, as it effectively lowers blood pressure without postural effects.
- Common side effects include **peripheral edema** and **reflex tachycardia**, but not orthostatic symptoms.
*Enalapril*
- As an **ACE inhibitor**, enalapril is generally well-tolerated but can cause **first-dose hypotension**, particularly in volume-depleted or elderly patients.
- While less likely than centrally acting agents to cause orthostatic hypotension, it is not the best choice when specifically avoiding this adverse effect.
- ACE inhibitors work on the **renin-angiotensin-aldosterone system** and are preferred in patients with diabetes or heart failure.
*Clonidine*
- Clonidine is a **centrally acting alpha-2 agonist** that reduces sympathetic outflow and commonly causes **significant orthostatic hypotension** due to impaired cardiovascular reflexes.
- It can also cause **sedation, dry mouth**, and **rebound hypertension** with abrupt withdrawal.
- This drug would worsen the patient's orthostatic symptoms.
*Methyldopa*
- Methyldopa is another **centrally acting alpha-2 agonist** that frequently causes **orthostatic hypotension** by reducing sympathetic tone.
- It is primarily used for **pregnancy-induced hypertension** due to its safety profile in pregnancy.
- This drug would be inappropriate for a patient experiencing orthostatic symptoms.
*Propranolol*
- Propranolol is a **non-selective beta-blocker** that can occasionally cause orthostatic symptoms, though this is not a primary adverse effect.
- It reduces **cardiac output** and **heart rate**, which may impair compensation for postural changes in some patients.
- Beta-blockers can also cause **fatigue, bradycardia**, and mask **hypoglycemia symptoms** in diabetic patients.
Question 109: A 27-year-old G1P0 woman at 25 weeks estimated gestational age presents with a blood pressure of 188/99 mm Hg during a routine prenatal visit. She has no symptoms, except for a mild headache. The patient's heart rate is 78/min. An injectable antihypertensive along with a beta-blocker is administered, and her blood pressure returns to normal within a couple of hours. She is sent home with advice to continue the beta-blocker. The patient returns after a couple of weeks with joint pain in both of her knees and fatigue. A blood test for anti-histone antibodies is positive. Which of the following is the mechanism of action of the intravenous antihypertensive medication most likely used in this patient?
A. Potassium channel activation
B. Calcium channel antagonism
C. Release endogenous nitric oxide
D. Interference with action of inositol trisphosphate (IP3) on intracellular calcium release (Correct Answer)
E. Inhibition of phosphodiesterase enzyme
Explanation: ***Interference with action of inositol trisphosphate (IP3) on intracellular calcium release***
- The clinical presentation of hypertension, especially during pregnancy, followed by **joint pain** and ** positive anti-histone antibodies**, strongly suggests **drug-induced lupus**.
- **Hydralazine** is a common cause of **drug-induced lupus** and acts by interfering with **IP3-mediated calcium release**, causing **vasodilatation**.
*Potassium channel activation*
- Medications like **minoxidil** and **diazoxide** activate potassium channels, leading to **hyperpolarization** and **vasorelaxation**.
- While effective antihypertensives, they are not typically associated with **drug-induced lupus**.
*Calcium channel antagonism*
- **Calcium channel blockers** (e.g., nifedipine, amlodipine) reduce intracellular calcium, leading to **smooth muscle relaxation**.
- These medications are generally safe in pregnancy but are not linked to **anti-histone antibody formation** or **drug-induced lupus**.
*Release endogenous nitrous oxide*
- **Nitrates** (e.g., nitroglycerin) release **nitric oxide**, which activates **guanylyl cyclase** and leads to **vasodilatation**.
- While used in hypertensive emergencies, they are not a common cause of **drug-induced lupus**.
*Inhibition of phosphodiesterase enzyme*
- **Phosphodiesterase inhibitors** (e.g., sildenafil) increase intracellular levels of **cAMP** or **cGMP**, leading to **vasodilatation**.
- These drugs are not the primary treatment for acute severe hypertension in pregnancy and do not typically cause **drug-induced lupus**.
Question 110: A 52-year-old woman with type 2 diabetes, treated with metformin, presents for a routine physical examination. Her vital signs are: pulse 85/min, respiratory rate 15/min, blood pressure 162/96 mm Hg, and temperature 37.0°C (98.6°F). A first-line antihypertensive drug is initiated. Which of the following is the most likely effect of this medication on the following parameters?
Parameters (in order):
1. 24-hour urine sodium
2. Aldosterone
3. Angiotensin II
4. Peripheral vascular resistance
5. Renin
A. Increased Decreased Decreased Decreased Increased (Correct Answer)
B. Increased Decreased Increased Decreased Increased
C. Increased Increased Increased Increased Increased
D. Decreased Increased Increased Decreased Increased
E. Increased Decreased Decreased Decreased Decreased
Explanation: ***Increased, Decreased, Decreased, Decreased, Increased***
* Given the patient's **type 2 diabetes** and **hypertension**, an **ACE inhibitor** or **ARB** would likely be initiated as a first-line agent due to their renoprotective effects and ability to control blood pressure.
* These drugs block the conversion of **angiotensin I to angiotensin II (ACE inhibitors)** or block **angiotensin II receptors (ARBs)**, leading to **decreased angiotensin II** and subsequent **decreased aldosterone**, **decreased peripheral vascular resistance**, and a **reflex increase in renin**. **Sodium excretion** would increase due to decreased aldosterone.
*Increased, Decreased, Increased, Decreased, Increased*
* This option incorrectly suggests an **increase in Angiotensin II (Ang II)** which would not occur with ACE inhibitors or ARBs, as these drugs work to lower Ang II levels.
* A decrease in peripheral vascular resistance is consistent, but the overall profile of hormonal changes is inaccurate for a first-line agent like an ACE inhibitor.
*Increased, Increased, Increased, Increased, Increased*
* This option suggests an overall increase in most parameters, which would indicate a drug that activates the **renin-angiotensin-aldosterone system (RAAS)** rather than inhibiting it.
* An **increase in peripheral vascular resistance** means the drug either constricts blood vessels or has no effect, which contradicts the goal of an antihypertensive.
*Decreased, Increased, Increased, Decreased, Increased*
* This option states **decreased 24-hour urine sodium**, which is inconsistent with the action of ACE inhibitors or ARBs, as the reduction in aldosterone should lead to increased sodium excretion.
* While **decreased peripheral vascular resistance** and **increased renin** are plausible, the rise in aldosterone and Ang II in conjunction with decreased sodium excretion makes this option less likely.
*Increased, Decreased, Decreased, Decreased, Decreased*
* This option proposes a **decrease in renin**, which would happen with direct renin inhibitors but not with ACE inhibitors or ARBs where a *reflex increase* in renin is expected due to the blockade of the negative feedback loop.
* Most other parameters align with ACE inhibitor/ARB action, but the **renin** change is incorrect for this class of drugs.
