Updated: 11/9/2020

Antihypertensives

0%
Topic
Review Topic
0
0
N/A
N/A
Questions
6
0
0
0%
0%
Evidence
11
0
0
Topic
Snapshot
  • A 54-year-old man presents to his primary care physician for an annual examination. In his previous visit, he was diagnosed with hypertension. In today's visit, his blood pressure has not improved given his difficulty to adhere to a diet with more fruits and vegetables and exercise. His medical history is significant for type II diabetes mellitus and he is currently taking metformin. Physical examination is remarkable for a blood pressure of 152/99 mmHg and mildly decreased vibration and proprioception sense in his lower extremities. He is started on lisinopril.
Introduction
  • Antihypertensive medications are used to manage hypertension in patients where conservative measures are ineffective
    •  there are four commonly used antihypertensive medications
      • diuretics
        • thiazides
        • potassium-sparing diuretics
      • sympatholytics
        • β-blockers
        • α-blockers
      • vasodilators
        • calcium channel blockers
        • hydralazine
        • minoxidil
      • renin-angiotensin-aldosterone inhibitors
        • angiotensin-converting enzyme (ACE) inhibitors
        • angiotensin receptor blockers (ARBs)
        • direct renin inhibitors
Diuretics
  • Medications
    • thiazides
      • mechanism of action
        • inhibits the NaCl transporter in the distal tubule
        • vasodilation (mechanism is unclear)
    • potassium-sparing diuretics
      • mechanism of action
        • promotes Na+ excretion in the distal nephron
  • Note that loop diuretic abuse can result in an increased sodium and potassium level in the urine 
Sympatholytics
  • Medications
    • β-blockers
      • mechanism
        • decreases heart rate, which decreases cardiac output
        • decreases renin release, which decreases total peripheral resistance
      • notes
        • can result in bronchospasm, impotence, and hypoglycemia 
        • can cause Raynaud phenomenon
          • treat with dihydropyridine calcium channel blocker 
      • e.g., metoprolol
    • α-blockers
      • mechanism
        • central α
          2
          -agonists
          • decreases the sympathetic outflow to blood vessels, heart, and kidneys
            • e.g., methyldopa and clonidine
        • α
          1
          -blockers
          • blood vessel smooth muscle relaxation
            • e.g., prazosin and terazosin
Vasodilators
  • Medications
    • hydralazine
      • mechanism
        • increases cGMP to cause direct vascular smooth muscle relaxation
      • note
        • this causes a reflex tachycardia; therefore, β-blockers are often given together
    • minoxidil
      • mechanism
        • direct arteriolar smooth muscle relaxation
    • calcium channel blockers
      • mechanism
        • decreases cardiac and vascular calcium influx, resulting in a decreased cardiac output and total vascular resistance
      • can result in peripheral edema   
        • treat with ACE inhibitors, changing the CCB, or changing the dose 
Renin-Angiotensin-Aldosterone Inhibitors
  • Medications
    • angiotensin-converting enzyme (ACE) inhibitors
      • mechanism
        • inhibits ACE, which decreases circulating angiotensin II (ATII)
          • recall that ATII causes
            • vascular vasoconstriction
            • increased aldosterone secretion from the adrenal gland (zona glomerulosa)
      • notes
        • decreases mortality in patients with
          • acute myocardial infarction
          • heart failure with decreased ejection fraction
        • can result in a cough 
        • beneficial for patients with diabetes
    • angiotensin receptor blockers (ARBs)
      • mechanism
        • directly blocks the AG-II receptor
      • notes
        • beneficial for patients with diabetes
Antihypertensives in Pregnancy
  • Medication options used to manage hypertension in pregnancy include
    • hydralazine
    • labetalol
    • methyldopa
    • nifedipine
Antihypertensives in Hypertensive Emergencies
  • Nitroprusside
    • mechanism
      • arteriolar and venous dilation via cGMP
    • notes
      • is metabolized into cyanide, which can potentially lead to cyanide poisoning
  • Fenoldopam
    • mechanism
      • a peripheral dopamine-1 receptor agonist
    • notes
      • maintains renal perfusion while the blood pressure is being decreased
        • therefore, it is beneficial in patients with renal impairment
  • Nicardipine and clevidipine
    • mechanism
      • decreases cardiac and vascular calcium influx
  • Labetalol
    • mechanism
      • α- and β-blocker
 
Antihypertensive Medications That Address Comorbid Conditions
 
Individualizing Antihypertensive Therapy
Condition Antihypertensive Medication
Benign prostatic hyperplasia
  • α-blockers
Essential tremor
  • β-blocker
Hyperthyroidism
  • β-blocker
Migraine
  • β-blocker
  • Calcium channel blocker
Osteoporosis
  • Thiazide diuretics
Raynaud phenomenon
  • Dihydropyridine calcium channel blocker
 
  • renin-angiotensin-aldosterone inhibitors

Please rate topic.

Average 4.2 of 5 Ratings

Questions (6)
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK

(M2.CV.16.29) A 26-year-old male is brought into the emergency room because he collapsed after working out. The patient is a jockey, and he states that he feels dehydrated and has an upcoming meet for which he needs to lose some weight. On exam, the patient has dry mucosa with cracked lips. His temperature is 98.9 deg F (37.2 deg C), blood pressure is 115/70 mmHg, pulse is 105/min, and respirations are 18/min. The patient's blood pressure upon standing up is 94/65 mmHg. His serum Na+ is 125 mEq/L and K+ is 3.0 mEq/L. His urinalysis reveals Na+ of 35 mEq/L and K+ of 32 mEq/L. The abuse of which of the following is most likely responsible for the patient's presentation?

QID: 104303
1

Furosemide

100%

(2/2)

2

Metoprolol

0%

(0/2)

3

Polyethylene glycol

0%

(0/2)

4

Spironolactone

0%

(0/2)

5

Amiloride

0%

(0/2)

M 6 E

Select Answer to see Preferred Response

Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Evidence (11)
EXPERT COMMENTS (8)
Private Note