Pharmacology Unit 7: Antihypertensive Drugs
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Questions and Answers

What is the primary function of the blood pressure in the human body?

  • To regulate body temperature
  • To maintain continuous blood circulation (correct)
  • To filter waste products from the blood
  • To supply oxygen to the brain
  • What is measured during blood pressure measurement?

  • The amount of friction the blood encounters as it flows through the blood vessels
  • The pressure in the arteries at the peak of ventricular contraction and relaxation (correct)
  • The volume of blood pumped by each ventricle in one contraction
  • The heart rate and stroke volume
  • Which of the following is NOT a factor affecting blood pressure?

  • Body temperature (correct)
  • Cardiac output
  • Peripheral resistance
  • Neural factors
  • What is the equation that relates blood pressure to its contributing factors?

    <p>BP = CO x PR</p> Signup and view all the answers

    What is the term for the volume of blood pumped by each ventricle in one contraction?

    <p>Stroke volume</p> Signup and view all the answers

    Which division of the autonomic nervous system has a significant impact on blood pressure?

    <p>Sympathetic division</p> Signup and view all the answers

    What is the unit of measurement for blood pressure?

    <p>Millimeters of mercury</p> Signup and view all the answers

    What is the purpose of the right atrium in the context of blood pressure?

    <p>To pump deoxygenated blood to the lungs</p> Signup and view all the answers

    What is the effect of sympathetic nerves on blood vessels?

    <p>Vasoconstriction</p> Signup and view all the answers

    What is the function of baroreceptors in large arteries?

    <p>To send warning signals in response to blood pressure changes</p> Signup and view all the answers

    What is the effect of exercise and stress on blood vessels?

    <p>Vasoconstriction in most body parts, except skeletal muscles</p> Signup and view all the answers

    What is the role of the kidneys in regulating blood pressure?

    <p>To alter blood volume and blood pressure</p> Signup and view all the answers

    What is the effect of diuretics on blood pressure?

    <p>Decrease blood pressure</p> Signup and view all the answers

    What happens when arterial blood pressure falls?

    <p>Kidneys retain body water, increasing blood volume and blood pressure</p> Signup and view all the answers

    What is the effect of angiotensin II on blood vessels?

    <p>Vasoconstriction</p> Signup and view all the answers

    What is the effect of heat on blood vessels?

    <p>Vasodilation</p> Signup and view all the answers

    What is the function of the renin-angiotensin-aldosterone system (RAAS)?

    <p>To increase blood pressure</p> Signup and view all the answers

    What is the effect of β-blockers on blood pressure?

    <p>Decrease blood pressure</p> Signup and view all the answers

    What is the effect of epinephrine on the body?

    <p>Increases both heart rate and blood pressure</p> Signup and view all the answers

    Why should people with hypertension quit smoking?

    <p>Smoking increases blood pressure by causing vasoconstriction</p> Signup and view all the answers

    What is the effect of alcohol on blood vessels?

    <p>Vasodilation</p> Signup and view all the answers

    What is the primary mechanism by which diuretics lower blood pressure?

    <p>By depleting body sodium stores</p> Signup and view all the answers

    Which of the following is a class of antihypertensive drugs that acts on the renin-angiotensin-aldosterone system?

    <p>ACE Inhibitors</p> Signup and view all the answers

    What is the mechanism of action of thiazide diuretics?

    <p>Blocking Na/Cl transporter in the renal distal convoluted tubule</p> Signup and view all the answers

    What is the effect of loop diuretics on renal blood flow?

    <p>Increased renal blood flow</p> Signup and view all the answers

    What is the equation that relates blood pressure to cardiac output and peripheral resistance?

    <p>BP = CO x PR</p> Signup and view all the answers

    What is the effect of baroreflexes on blood pressure?

    <p>Regulate blood pressure through the sympathetic nervous system</p> Signup and view all the answers

    What is the primary mechanism by which β-blockers lower blood pressure?

    <p>By decreasing heart rate</p> Signup and view all the answers

    What is the result of propranolol's negative inotropic and chronotropic effects on the heart?

    <p>Decreased cardiac output and heart rate</p> Signup and view all the answers

    Why must β-blockers be tapered over a few weeks in patients with hypertension and ischemic heart disease?

    <p>To reduce the risk of myocardial infarction and sudden death</p> Signup and view all the answers

    What is the therapeutic use of propranolol in addition to hypertension?

    <p>Migraine, Hyperthyroidism, Angina pectoris, and Myocardial infarction</p> Signup and view all the answers

    What is the receptor specificity of nebivolol?

    <p>β1, β2, NO↑</p> Signup and view all the answers

    What is the effect of β-blockers on heart rate during exercise or stress?

    <p>Attenuate the expected increase in heart rate</p> Signup and view all the answers

    Which of the following β-adrenergic antagonists is a selective β1 receptor blocker?

    <p>Atenolol</p> Signup and view all the answers

    What is the effect of ACE inhibitors on blood pressure?

    <p>Decrease peripheral vascular resistance</p> Signup and view all the answers

    What is a rare but potentially life-threatening reaction to ACE inhibitors?

    <p>Angioedema</p> Signup and view all the answers

    What is the therapeutic use of timolol?

    <p>Glaucoma and Hypertension</p> Signup and view all the answers

    What is the mechanism of action of ACE inhibitors?

    <p>Blocking the enzyme ACE</p> Signup and view all the answers

    What is the primary mechanism of action of potassium-sparing diuretics?

    <p>Inhibiting epithelial sodium transport at the late distal and collecting ducts</p> Signup and view all the answers

    Which of the following diuretics is an aldosterone receptor antagonist?

    <p>Spironolactone</p> Signup and view all the answers

    What is the primary effect of β-blockers on the cardiovascular system?

    <p>Decrease cardiac output</p> Signup and view all the answers

    What is the primary mechanism of action of thiazide diuretics?

    <p>Blocking Na/Cl transporter in renal distal convoluted tubule</p> Signup and view all the answers

    Which of the following β-blockers is a selective blocker of β1-receptors?

    <p>Metoprolol</p> Signup and view all the answers

    What is the primary effect of nonselective β-blockers on the lungs?

    <p>Bronchoconstriction</p> Signup and view all the answers

    What is the primary effect of β-blockers on the renin-angiotensin-aldosterone system?

    <p>Decrease renin release</p> Signup and view all the answers

    What is a common adverse effect of β-blockers?

    <p>Bradycardia</p> Signup and view all the answers

    Which of the following diuretics is often used in combination with loop diuretics and thiazides?

    <p>Amiloride</p> Signup and view all the answers

    What is the primary effect of noncardioselective β-blockers on serum lipid patterns?

    <p>Decrease high-density lipoprotein cholesterol</p> Signup and view all the answers

    Which of the following is a renin inhibitor?

    <p>Aliskiren</p> Signup and view all the answers

    What is the main effect of calcium channel blockers on blood vessels?

    <p>Dilation of arterioles</p> Signup and view all the answers

    Which of the following angiotensin II receptor blockers is available in the form of medoxomil?

    <p>Azilsartan</p> Signup and view all the answers

    What is the common side effect of verapamil?

    <p>Constipation</p> Signup and view all the answers

    What is the effect of α1-adrenoceptor blockers on blood vessels?

    <p>Decreased vasoconstriction</p> Signup and view all the answers

    Which of the following drugs is suitable for pregnant women with hypertension?

    <p>Labetalol</p> Signup and view all the answers

    What is the effect of clonidine on blood pressure?

    <p>Decreased sympathetic outflow</p> Signup and view all the answers

    What is the common side effect of dihydropyridines?

    <p>Peripheral edema</p> Signup and view all the answers

    What is the effect of methyldopa on the body?

    <p>Decreases sympathetic outflow</p> Signup and view all the answers

    Which of the following drugs is used in the treatment of heart failure?

    <p>Carvedilol</p> Signup and view all the answers

    What is the direction of blood flow in the body?

    <p>From the left atrium to the left ventricle and then to the aorta</p> Signup and view all the answers

    What is the term for the pressure in the arteries when the ventricles are relaxing?

    <p>Diastolic pressure</p> Signup and view all the answers

    Which of the following factors increases peripheral resistance?

    <p>Increased friction in blood vessels</p> Signup and view all the answers

    What happens to blood pressure when the kidneys retain body water?

    <p>It increases</p> Signup and view all the answers

    What is the equation that relates blood pressure to its contributing factors?

    <p>BP = CO x PR</p> Signup and view all the answers

    What is the autonomic nervous system division that plays a significant role in blood pressure regulation?

    <p>Sympathetic division</p> Signup and view all the answers

    What is the effect of angiotensin II on blood vessels?

    <p>Vasoconstriction</p> Signup and view all the answers

    What is the unit of measurement for blood pressure?

    <p>Millimeters of mercury (mm Hg)</p> Signup and view all the answers

    What is the role of baroreceptors in large arteries?

    <p>To detect changes in blood pressure</p> Signup and view all the answers

    What is the term for the amount of blood pumped out of the left ventricle per minute?

    <p>Cardiac output</p> Signup and view all the answers

    What is the effect of diuretics on blood volume?

    <p>Decrease</p> Signup and view all the answers

    What is the factor that determines the amount of blood pumped by each ventricle in one contraction?

    <p>Stroke volume</p> Signup and view all the answers

    What is the effect of sympathetic nervous system on cardiac output?

    <p>Increase</p> Signup and view all the answers

    What is the role of renin in the renin-angiotensin-aldosterone system?

    <p>To convert angiotensinogen to angiotensin I</p> Signup and view all the answers

    What is the effect of heat on blood vessels?

    <p>Vasodilation</p> Signup and view all the answers

    What is the effect of β-blockers on blood pressure?

    <p>Decrease</p> Signup and view all the answers

    What is the role of the kidneys in regulating blood pressure?

    <p>To regulate blood volume</p> Signup and view all the answers

    What is the effect of cold on blood vessels?

    <p>Vasoconstriction</p> Signup and view all the answers

    Which of the following substances increases blood pressure by causing vasoconstriction?

    <p>Nicotine</p> Signup and view all the answers

    What is the effect of diuretics on stroke volume?

    <p>It decreases</p> Signup and view all the answers

    Which of the following is a class of antihypertensive drugs that acts on the renin-angiotensin-aldosterone system?

    <p>ACE Inhibitors</p> Signup and view all the answers

    What is the primary mechanism by which thiazide diuretics lower blood pressure?

    <p>By increasing sodium and water excretion</p> Signup and view all the answers

    What is the effect of loop diuretics on renal blood flow?

    <p>It increases</p> Signup and view all the answers

    Which of the following is a mechanism by which baroreflexes regulate blood pressure?

    <p>By changing the activity of the sympathetic nervous system</p> Signup and view all the answers

    What is the effect of β-blockers on heart rate?

    <p>It decreases</p> Signup and view all the answers

    What is the effect of vasodilators on peripheral resistance?

    <p>It decreases</p> Signup and view all the answers

    Which of the following substances causes vasodilation and decreases blood pressure?

    <p>Alcohol and Histamine</p> Signup and view all the answers

    What is the primary mechanism by which ACE inhibitors lower blood pressure?

    <p>By decreasing angiotensin II production</p> Signup and view all the answers

    What is the primary function of potassium-sparing diuretics?

    <p>Reduce potassium loss in the urine</p> Signup and view all the answers

    Which of the following diuretics inhibits epithelial sodium transport at the late distal and collecting ducts?

    <p>Amiloride</p> Signup and view all the answers

    What is the mechanism of action of β-adrenoceptor blockers?

    <p>Decrease cardiac output</p> Signup and view all the answers

    Which of the following is a selective blocker of β1-receptors?

    <p>Metoprolol</p> Signup and view all the answers

    What is the effect of nonselective β-blockers on the lungs?

    <p>Bronchoconstriction</p> Signup and view all the answers

    What is the primary mechanism of action of thiazide diuretics?

    <p>Block Na/Cl transporter in the renal distal convoluted tubule</p> Signup and view all the answers

    What is the effect of β-blockers on serum lipid patterns?

    <p>Decrease high-density lipoprotein cholesterol and increase triglycerides</p> Signup and view all the answers

    Which of the following is an aldosterone receptor antagonist?

    <p>Spironolactone</p> Signup and view all the answers

    What is the primary effect of β-blockers on the cardiovascular system?

    <p>Decrease cardiac output</p> Signup and view all the answers

    Which of the following diuretics is often used in combination with loop diuretics and thiazides?

    <p>Potassium-sparing diuretics</p> Signup and view all the answers

    What is the effect of propranolol on cardiac output, workload, and oxygen consumption?

    <p>Decreased</p> Signup and view all the answers

    What is the receptor specificity of carvedilol?

    <p>α1, β1, β2</p> Signup and view all the answers

    Why should β-blockers be tapered over a few weeks in patients with hypertension and ischemic heart disease?

    <p>To prevent both angina and sudden death</p> Signup and view all the answers

    What is the effect of ACE inhibitors on angiotensin II?

    <p>Inhibition of formation</p> Signup and view all the answers

    What is the therapeutic use of esmolol?

    <p>Myocardial infarction</p> Signup and view all the answers

    What is the receptor specificity of atenolol?

    <p>β1</p> Signup and view all the answers

    What is the effect of β-blockers on lipid metabolism?

    <p>Increased LDL and decreased HDL</p> Signup and view all the answers

    What is the mechanism of action of angiotensin II receptor blockers?

    <p>Blockade of AT1 receptors</p> Signup and view all the answers

    What is the therapeutic use of nebivolol?

    <p>Hypertension</p> Signup and view all the answers

    What is the receptor specificity of labetalol?

    <p>α1, β1, β2</p> Signup and view all the answers

    What is the mechanism of action of aliskiren?

    <p>Directly inhibits renin</p> Signup and view all the answers

    Which of the following calcium channel blockers can cause gingival hyperplasia?

    <p>Nifedipine</p> Signup and view all the answers

    What is the effect of prazosin, doxazosin, and terazosin on peripheral vascular resistance?

    <p>Decrease peripheral vascular resistance</p> Signup and view all the answers

    Which of the following drugs is used in the treatment of heart failure?

    <p>Carvedilol</p> Signup and view all the answers

    What is the mechanism of action of clonidine?

    <p>Acts centrally as an α2-agonist</p> Signup and view all the answers

    Which of the following drugs is a dihydropyridine calcium channel blocker?

    <p>Felodipine</p> Signup and view all the answers

    What is the effect of α1-adrenoceptor blocking agents on vasoconstriction?

    <p>Decrease vasoconstriction</p> Signup and view all the answers

    What is the primary mechanism of action of methyldopa?

    <p>Converted to methyl norepinephrine centrally to diminish adrenergic outflow</p> Signup and view all the answers

    Which of the following drugs is a selective α1-adrenoceptor blocker?

    <p>Doxazosin</p> Signup and view all the answers

    What is a common adverse effect of dihydropyridine calcium channel blockers?

    <p>Peripheral edema</p> Signup and view all the answers

    Study Notes

    Definition of Terms

    • Blood Pressure: The pressure exerted by blood on the inner walls of blood vessels, keeping blood circulating between heartbeats.
      • Measured in mm Hg (millimeters of mercury)
      • Reported as systolic pressure (peak contraction) and diastolic pressure (relaxation)

    Hydraulic Equation of Blood Pressure

    • BP = CO x PR
      • Cardiac Output (CO): Amount of blood pumped out of the left ventricle per minute
        • Determined by Stroke Volume (SV) and Heart Rate (HR)
      • Peripheral Resistance (PR): Friction encountered by blood flowing through blood vessels
        • Increased peripheral resistance increases blood pressure

    Factors Affecting Blood Pressure

    • Neural Factors: Autonomic Nervous System
      • Parasympathetic Division: Little or no effect on blood pressure
      • Sympathetic Nerves: Cause vasoconstriction, increasing blood pressure
      • B-blockers: Adrenergic antagonists that lower blood pressure
    • Renal Factors: The Kidneys
      • Kidneys regulate arterial blood pressure by altering blood volume
      • Diuretics: Stimulate kidneys to remove water from blood, decreasing blood volume and pressure
    • Temperature
      • Cold: Vasoconstricting effect
      • Heat: Vasodilating effect
    • Chemical Substances
      • Epinephrine: Increases heart rate and blood pressure
      • Nicotine: Causes vasoconstriction, increasing blood pressure
      • Alcohol & Histamine: Cause vasodilation, decreasing blood pressure
    • Diet
      • Low in salt, saturated fats, and cholesterol: Helps prevent hypertension
      • Diuretics: Affect stroke volume
      • B-blockers: Affect heart rate
      • Vasodilators: Affect peripheral resistance

    Mechanisms of Controlling Blood Pressure

    • Hydraulic Equation of Blood Pressure: BP = CO x PR
    • Cardiac Output (CO) and Peripheral Resistance (PR): Controlled by overlapping mechanisms:
      • Baroreflexes
      • Renin-Angiotensin-Aldosterone System (RAAS)

    Baroreflex

    • Acts by changing sympathetic nervous system activity
    • Rapid, moment-to-moment regulation of blood pressure

    Renin-Angiotensin-Aldosterone System (RAAS)

    • Stimulates renin release from kidneys
    • Increases sodium and water retention, blood volume, and blood pressure

    Different Classes of Antihypertensive Drugs

    • Diuretics
    • β-Adrenoceptor Blockers
    • ACE (Angiotensin Converting Enzyme) Inhibitors
    • Angiotensin II Receptor Blockers (ARB)
    • Renin Inhibitor
    • Calcium Channel Blockers
    • α-Adrenoceptor Blocking Agents
    • α-/β-Adrenoceptor Blocking Agents
    • Centrally Acting Adrenergic Drugs
    • Vasodilators

    Diuretics

    • Function: Lower blood pressure by depleting body sodium stores
    • Mechanism: Act on stroke volume
    • Classes:
      • Thiazide Diuretics
      • Loop Diuretics
      • Potassium-Sparing Diuretics

    β-Adrenoceptor Blockers

    • Function: Reduce blood pressure by decreasing cardiac output
    • Mechanism: Block β1- and β2-receptors
    • Effects:
      • Decrease heart rate
      • Decrease renin release
      • Reduce blood pressure by inhibiting renin-angiotensin-aldosterone system
    • Adverse Effects:
      • Bradycardia
      • Hypotension
      • CNS side effects (fatigue, lethargy, insomnia)
      • Decreased libido and erectile dysfunction
    • Alterations in Serum Lipid Patterns: Noncardioselective β-blockers may disturb lipid metabolism

    ACE (Angiotensin Converting Enzyme) Inhibitors

    • Action: Lower blood pressure by reducing peripheral vascular resistance
    • Mechanism: Block ACE, reducing angiotensin II formation
    • Adverse Effects:
      • Dry cough
      • Rash
      • Fever
      • Altered taste
      • Hypotension
      • Hyperkalemia
    • Angioedema: Rare but potentially life-threatening reaction

    Angiotensin II Receptor Blockers (ARB)

    • Action: Lower blood pressure by reducing peripheral vascular resistance
    • Mechanism: Block AT1 receptors, decreasing angiotensin II activation
    • Adverse Effects: Similar to ACE inhibitors, but with reduced risk of cough and angioedema

    Renin Inhibitor

    • Action: Directly inhibits renin, reducing angiotensin II formation
    • Mechanism: Acts earlier in the renin-angiotensin-aldosterone system than ACE inhibitors or ARBs
    • Adverse Effects: Diarrhea, cough, and angioedema (less frequent than ACE inhibitors)

    Calcium Channel Blockers

    • Action: Lower blood pressure by relaxing vascular smooth muscle
    • Mechanism: Block L-type calcium channels in the heart and smooth muscle
    • Adverse Effects:
      • Dizziness
      • Headache
      • Fatigue
      • Peripheral edema
      • Gingival hyperplasia (dihydropyridines)

    α-Adrenoceptor Blocking Agents

    • Action: Lower blood pressure by blocking α1-adrenoceptors

    • Mechanism: Relax both arterial and venous smooth muscle

    • Adverse Effects:

      • Dizziness
      • Headache
      • Fatigue
      • Orthostatic hypotension### Inhibition of α1 Binding
    • Inhibition of α1 binding leads to decreased vasoconstriction, decreased peripheral resistance (PR), and decreased blood pressure (BP)

    • α1 binding is blocked by prazosin, doxazosin, or terazosin, which prevents norepinephrine (NE) and epinephrine (E) binding

    Adverse Effects

    • Reflex tachycardia and postural hypotension often occur at the onset of treatment and with dose increases, requiring slow titration of the drug in divided doses
    • Orthostatic hypotension leads to low blood pressure and lightheadedness upon standing up

    α-/β-Adrenoceptor Blocking Agents

    • Labetalol and Carvedilol block α1, β1, and β2 receptors
    • Not suitable for patients with asthma
    • Carvedilol is an effective antihypertensive, used in the treatment of heart failure
    • Labetalol is used in the management of gestational hypertension and hypertensive emergencies, and is suitable for pregnant women
    • Carvedilol, Metoprolol Succinate, and Bisoprolol have been shown to reduce morbidity and mortality associated with heart failure

    Centrally Acting Adrenergic Drugs

    • Clonidine acts centrally as an α2-agonist, decreasing sympathetic outflow to the periphery
    • Clonidine is used for hypertension complicated by renal disease
    • Methyldopa is converted to methyl norepinephrine centrally, diminishing adrenergic outflow from the CNS
    • Methyldopa is commonly associated with sedation and drowsiness, and has limited use due to adverse effects and the need for multiple daily doses
    • Methyldopa is mainly used for hypertension in pregnancy due to its safety record

    Vasodilators

    • Vasodilators act by producing relaxation of vascular smooth muscle, primarily in arteries and arterioles

    Additional Information

    • Hydralazine and Minoxidil are not used as primary drugs to treat hypertension
    • Hydralazine is administered with a β-blocker and a diuretic
    • Minoxidil is used to treat hypertrochosis (growth of body hair) and is used topically for male pattern baldness

    Definition of Terms

    • Blood Pressure: The pressure exerted by blood on the inner walls of blood vessels, keeping blood circulating between heartbeats.
      • Measured in mm Hg (millimeters of mercury)
      • Reported as systolic pressure (peak contraction) and diastolic pressure (relaxation)

    Hydraulic Equation of Blood Pressure

    • BP = CO x PR
      • Cardiac Output (CO): Amount of blood pumped out of the left ventricle per minute
        • Determined by Stroke Volume (SV) and Heart Rate (HR)
      • Peripheral Resistance (PR): Friction encountered by blood flowing through blood vessels
        • Increased peripheral resistance increases blood pressure

    Factors Affecting Blood Pressure

    • Neural Factors: Autonomic Nervous System
      • Parasympathetic Division: Little or no effect on blood pressure
      • Sympathetic Nerves: Cause vasoconstriction, increasing blood pressure
      • B-blockers: Adrenergic antagonists that lower blood pressure
    • Renal Factors: The Kidneys
      • Kidneys regulate arterial blood pressure by altering blood volume
      • Diuretics: Stimulate kidneys to remove water from blood, decreasing blood volume and pressure
    • Temperature
      • Cold: Vasoconstricting effect
      • Heat: Vasodilating effect
    • Chemical Substances
      • Epinephrine: Increases heart rate and blood pressure
      • Nicotine: Causes vasoconstriction, increasing blood pressure
      • Alcohol & Histamine: Cause vasodilation, decreasing blood pressure
    • Diet
      • Low in salt, saturated fats, and cholesterol: Helps prevent hypertension
      • Diuretics: Affect stroke volume
      • B-blockers: Affect heart rate
      • Vasodilators: Affect peripheral resistance

    Mechanisms of Controlling Blood Pressure

    • Hydraulic Equation of Blood Pressure: BP = CO x PR
    • Cardiac Output (CO) and Peripheral Resistance (PR): Controlled by overlapping mechanisms:
      • Baroreflexes
      • Renin-Angiotensin-Aldosterone System (RAAS)

    Baroreflex

    • Acts by changing sympathetic nervous system activity
    • Rapid, moment-to-moment regulation of blood pressure

    Renin-Angiotensin-Aldosterone System (RAAS)

    • Stimulates renin release from kidneys
    • Increases sodium and water retention, blood volume, and blood pressure

    Different Classes of Antihypertensive Drugs

    • Diuretics
    • β-Adrenoceptor Blockers
    • ACE (Angiotensin Converting Enzyme) Inhibitors
    • Angiotensin II Receptor Blockers (ARB)
    • Renin Inhibitor
    • Calcium Channel Blockers
    • α-Adrenoceptor Blocking Agents
    • α-/β-Adrenoceptor Blocking Agents
    • Centrally Acting Adrenergic Drugs
    • Vasodilators

    Diuretics

    • Function: Lower blood pressure by depleting body sodium stores
    • Mechanism: Act on stroke volume
    • Classes:
      • Thiazide Diuretics
      • Loop Diuretics
      • Potassium-Sparing Diuretics

    β-Adrenoceptor Blockers

    • Function: Reduce blood pressure by decreasing cardiac output
    • Mechanism: Block β1- and β2-receptors
    • Effects:
      • Decrease heart rate
      • Decrease renin release
      • Reduce blood pressure by inhibiting renin-angiotensin-aldosterone system
    • Adverse Effects:
      • Bradycardia
      • Hypotension
      • CNS side effects (fatigue, lethargy, insomnia)
      • Decreased libido and erectile dysfunction
    • Alterations in Serum Lipid Patterns: Noncardioselective β-blockers may disturb lipid metabolism

    ACE (Angiotensin Converting Enzyme) Inhibitors

    • Action: Lower blood pressure by reducing peripheral vascular resistance
    • Mechanism: Block ACE, reducing angiotensin II formation
    • Adverse Effects:
      • Dry cough
      • Rash
      • Fever
      • Altered taste
      • Hypotension
      • Hyperkalemia
    • Angioedema: Rare but potentially life-threatening reaction

    Angiotensin II Receptor Blockers (ARB)

    • Action: Lower blood pressure by reducing peripheral vascular resistance
    • Mechanism: Block AT1 receptors, decreasing angiotensin II activation
    • Adverse Effects: Similar to ACE inhibitors, but with reduced risk of cough and angioedema

    Renin Inhibitor

    • Action: Directly inhibits renin, reducing angiotensin II formation
    • Mechanism: Acts earlier in the renin-angiotensin-aldosterone system than ACE inhibitors or ARBs
    • Adverse Effects: Diarrhea, cough, and angioedema (less frequent than ACE inhibitors)

    Calcium Channel Blockers

    • Action: Lower blood pressure by relaxing vascular smooth muscle
    • Mechanism: Block L-type calcium channels in the heart and smooth muscle
    • Adverse Effects:
      • Dizziness
      • Headache
      • Fatigue
      • Peripheral edema
      • Gingival hyperplasia (dihydropyridines)

    α-Adrenoceptor Blocking Agents

    • Action: Lower blood pressure by blocking α1-adrenoceptors

    • Mechanism: Relax both arterial and venous smooth muscle

    • Adverse Effects:

      • Dizziness
      • Headache
      • Fatigue
      • Orthostatic hypotension### Inhibition of α1 Binding
    • Inhibition of α1 binding leads to decreased vasoconstriction, decreased peripheral resistance (PR), and decreased blood pressure (BP)

    • α1 binding is blocked by prazosin, doxazosin, or terazosin, which prevents norepinephrine (NE) and epinephrine (E) binding

    Adverse Effects

    • Reflex tachycardia and postural hypotension often occur at the onset of treatment and with dose increases, requiring slow titration of the drug in divided doses
    • Orthostatic hypotension leads to low blood pressure and lightheadedness upon standing up

    α-/β-Adrenoceptor Blocking Agents

    • Labetalol and Carvedilol block α1, β1, and β2 receptors
    • Not suitable for patients with asthma
    • Carvedilol is an effective antihypertensive, used in the treatment of heart failure
    • Labetalol is used in the management of gestational hypertension and hypertensive emergencies, and is suitable for pregnant women
    • Carvedilol, Metoprolol Succinate, and Bisoprolol have been shown to reduce morbidity and mortality associated with heart failure

    Centrally Acting Adrenergic Drugs

    • Clonidine acts centrally as an α2-agonist, decreasing sympathetic outflow to the periphery
    • Clonidine is used for hypertension complicated by renal disease
    • Methyldopa is converted to methyl norepinephrine centrally, diminishing adrenergic outflow from the CNS
    • Methyldopa is commonly associated with sedation and drowsiness, and has limited use due to adverse effects and the need for multiple daily doses
    • Methyldopa is mainly used for hypertension in pregnancy due to its safety record

    Vasodilators

    • Vasodilators act by producing relaxation of vascular smooth muscle, primarily in arteries and arterioles

    Additional Information

    • Hydralazine and Minoxidil are not used as primary drugs to treat hypertension
    • Hydralazine is administered with a β-blocker and a diuretic
    • Minoxidil is used to treat hypertrochosis (growth of body hair) and is used topically for male pattern baldness

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    Description

    This quiz covers the basics of antihypertensive drugs, including the definition of blood pressure, measuring blood pressure, and systolic pressure.

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