NE Blockers
48 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is a common side effect associated with the use of alpha blockers?

  • Increased heart rate
  • Drowsiness
  • Postural hypotension (correct)
  • Nausea

    • Which medication is used primarily to treat Benign Prostatic Hyperplasia (BPH) due to its ability to block smooth muscle contraction?

  • Ergot derivatives
  • Beta blockers
  • Tamsulosin (correct)
  • Phenoxybenzamine

    • Which alpha antagonist has an irreversible action and is utilized in long-term management?

  • Terazosin
  • Prazosin
  • Phenoxybenzamine (correct)
  • Doxazosin

    • In the context of treating pheochromocytoma, which of the following agents is among the drugs of choice?

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

    What physiological effect do alpha antagonists generally have on blood pressure?

    <p>Cause vasodilation</p> Signup and view all the answers

    What condition can often be diagnosed by observing elevated urinary metabolites of norepinephrine and epinephrine?

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

    Which of the following best describes the mechanism of action of beta antagonists?

    <p>Competitive blockade of catecholamines</p> Signup and view all the answers

    Which of the following treatments would be least effective for hypertensive emergencies?

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

    Which of the following beta antagonists is known for its lipophilic nature and ability to cross the blood-brain barrier?

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

    What is the common characteristic of beta antagonists listed in the context?

    <p>They have large volumes of distribution.</p> Signup and view all the answers

    Which of the following agents is NOT classified as a beta antagonist?

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

    Which of these agonists is primarily associated with beta receptor stimulation leading to increased heart rate?

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

    What physiological effect is associated with activation of alpha adrenergic receptors?

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

    Which of the following drugs belongs to the category of sympatholytics?

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

    Which receptor is responsible for the increased contraction force of the heart when stimulated by agonists?

    <p>Beta-1</p> Signup and view all the answers

    Among the listed options, which agent is used primarily for its agonist properties on beta receptors?

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

    Which condition can be treated with Prazosin?

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

    What is a potential side effect of non-selective beta antagonists?

    <p>Worsening asthma conditions</p> Signup and view all the answers

    What is a common use of beta blockers among musicians?

    <p>To alleviate stage fright</p> Signup and view all the answers

    What effect do beta antagonists have on cardiac function in diseased patients?

    <p>Possibly provoke cardiac failure</p> Signup and view all the answers

    Which of the following beta blockers is commonly used as eye drops for glaucoma?

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

    Which of the following is a treatment option for pheochromocytoma?

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

    What is one of the CNS effects associated with high lipid solubility beta antagonists?

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

    What is the primary clinical use of alpha1 selective antagonists?

    <p>Treating hypertension and benign prostatic hyperplasia</p> Signup and view all the answers

    What distinguishes irreversible alpha antagonists from reversible ones?

    <p>They require new receptor synthesis for action termination</p> Signup and view all the answers

    Which drug is used to delay absorption when administered with local anesthetic during anaphylactic shock?

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

    Which of the following symptoms is typically caused by a pheochromocytoma?

    <p>Palpitations and sweating</p> Signup and view all the answers

    Which statement accurately describes the role of sympatholytics?

    <p>They block alpha and beta adrenergic receptors</p> Signup and view all the answers

    Which condition is associated with more than 85% of pheochromocytomas?

    <p>Adrenal tumor development</p> Signup and view all the answers

    What pharmacological treatment is commonly recommended for pre-operative stabilization in pheochromocytoma cases?

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

    In terms of mechanism, what is the consequence of adrenergic receptor blockade in the PNS?

    <p>Reduced physiological response to stress</p> Signup and view all the answers

    What physiological effect can occur due to the palpation of the abdomen in a patient with pheochromocytoma?

    <p>Increase in heart rate and blood pressure</p> Signup and view all the answers

    Which of the following statements about alpha antagonists is accurate?

    <p>Irreversible alpha antagonists cause a longer-lasting effect compared to reversible ones.</p> Signup and view all the answers

    What is the primary action of clonidine in relation to sympathetic activity?

    <p>It acts as an agonist at alpha 2 receptors to reduce sympathetic activity.</p> Signup and view all the answers

    Which of the following is a non-selective beta antagonist?

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

    What does the term 'EP reversal' refer to?

    <p>The contrasting effects of alpha and beta receptor activation in the same tissue.</p> Signup and view all the answers

    Phentolamine can be effectively used for which of the following conditions?

    <p>Management of pheochromocytoma-induced hypertensive crisis.</p> Signup and view all the answers

    Which drug acts as a selective alpha 1 antagonist?

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

    Which mechanism describes the function of sympatholytics?

    <p>They block postsynaptic receptors in vascular smooth muscle.</p> Signup and view all the answers

    How do irreversible alpha antagonists differ from reversible ones?

    <p>Their effects persist even after the drug is stopped.</p> Signup and view all the answers

    What effect do beta antagonists have on the cardiovascular system?

    <p>Lower blood pressure by affecting multiple systems</p> Signup and view all the answers

    Which beta blocker is known for its selectivity towards beta 1 receptors primarily impacting the heart?

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

    How do beta 2 selective blockers impact patients with diabetes?

    <p>Reduce glycogenolysis and inhibit lipolysis</p> Signup and view all the answers

    What is the primary treatment mechanism for glaucoma using beta blockers?

    <p>Reduce intraocular pressure by decreasing aqueous humor secretion</p> Signup and view all the answers

    What condition is NOT directly treated by beta antagonists?

    <p>Bacterial infections</p> Signup and view all the answers

    Which of the following statements accurately describes Nadolol?

    <p>It is known for having a long duration of action.</p> Signup and view all the answers

    Propranolol is associated with which of the following side effects?

    <p>Numerous CNS effects</p> Signup and view all the answers

    In which scenario is the use of beta blockers considered potentially harmful?

    <p>In diabetic patients due to potential metabolic changes</p> Signup and view all the answers

    Study Notes

    Pharmacology I: Chapter 10 NE Blockers (Sympatholytics)

    • Case Study 1: A 46-year-old female presented with headache, palpitations, drenching sweats, and blood pressure (BP) of 150/90 mmHg and heart rate 88 bpm. Abdominal palpation caused BP to rise to 210/120 mmHg and heart rate to 122 bpm. Cause and treatment were unknown.

    • Case Study 2: The patient was diagnosed with pheochromocytoma. The examination triggered another catecholamine release episode. Pre-operative treatment with phenoxybenzamine or phentolamine was needed to stabilize the patient.

    Sympatholytics (Adrenergic Receptor Antagonists)

    • Sympatholytics block alpha and beta receptors mainly in the peripheral nervous system (PNS).

    • Sympatholytics block endogenous catecholamines and related agonist drugs.

    • Blocking PNS dopamine receptors does not have significant clinical use, but CNS antagonism is important.

    Sympatholytics: Clinical Uses

    • Nonselective alpha antagonists: Used to treat pheochromocytoma.

    • Alpha 1 selective antagonists: Used to treat hypertension and benign prostatic hyperplasia (BPH).

    • Beta antagonists: Used to treat hypertension, ischemic heart disease, and neurological disorders.

    Pheochromocytoma

    • A tumor derived from neural crest cells in the sympathetic nervous system.

    • Accounts for approximately 2% of all cases of hypertension.

    • The tumor releases norepinephrine (NE) and epinephrine (EP), causing palpitations, sweating, headaches, and hypertension.

    • About 85% of tumors are located in the adrenal gland, with the remainder located elsewhere.

    • Surgical intervention is often necessary following treatment with phenoxybenzamine.

    Alpha Antagonists

    • Types: Classified as reversible or irreversible based on their binding to receptors.

    • Reversible: Drugs' duration of action is related to their half-life (t1/2). Examples include phentolamine, tolazoline, prazosin, labetalol.

    • Irreversible: Drugs form covalent bonds with receptors, and their effect continues for days after administration. Examples include phenoxybenzamine. A new receptor synthesis is needed to restore function.

    • List of Drugs:

      • Reversible: phentolamine, tolazoline, prazosin, labetalol
      • Irreversible: phenoxybenzamine

    Adrenergic Antagonists: List of Drugs

    • Alpha-1 selective: Prazosin, Terazosin, Doxazosin
    • Nonselective Alpha: Phentolamine, phenoxybenzamine
    • Beta-1 selective: Acebutolol, Atenolol, Bisoprolol, Metoprolol
    • Nonselective Beta: Carteolol, Bucindolol, Nadolol, Penbutolol, Timolol

    Main Mechanisms of Sympathetic Block

    • Decrease in sympathetic outflow from the brain.

    • Suppression of norepinephrine (NE) release from nerve terminals.

    • Blockage of postsynaptic receptors.

    Alpha 2-agonists (e.g., clonidine)

    • Reduces sympathetic activity.

    • Acts antagonistically at alpha 2 receptors.

    • Used to manage hypertension.

    • Alpha 2 activation inhibits sympathetic outflow from the brain and norepinephrine release.

    Alpha Blockers

    • Mostly cause vasodilation, leading to decreased blood pressure.
    • Alpha agonists cause vasoconstriction.
    • Postural hypotension: Standing requires more norepinephrine (NE) to regulate BP; lying down requires less NE to control BP. Alpha blockers are most effective when NE levels are highest (standing), so postural hypotension (low BP upon standing) may result.

    Alpha Blockers Side Effects

    • Postural hypotension.
    • Reflex tachycardia

    Pheochromocytoma and Alpha Antagonists

    • Adrenal medulla tumors usually release norepinephrine (NE) and epinephrine (EP), leading to high blood pressure, sweating, palpitations, and headaches (symptoms due to catecholamine excess).
    • Diagnosis through urinary NE, EP metabolites (VMA), CT, and MRI.
    • Phenoxybenzamine and phentolamine are often the drugs of choice before (pre-) and after (post-) surgery for this issue.

    Hypertensive Emergencies and Chronic Hypertension

    • Sympatholytics are of limited use in hypertensive emergencies; beta blockers are usually preferred.
    • Prazosin and other alpha 1 selective blockers are used in chronic hypertension.

    Urinary Obstruction

    • Certain sympatholytics are used to treat benign prostatic hyperplasia (BPH) by blocking smooth muscle contraction in the enlarged prostate.
      • Examples: Prazosin, Doxazosin, Terazosin

    Beta Blockers

    • Mechanism: These drugs block catecholamine (NE, EP) actions at beta receptors.

    • Most bind competitively, not irreversibly; most are pure antagonists and not partial agonists.

    • Some act as partial agonists (inhibition in the presence of endogenously-produced agonists; stimulate in their absence)

    • Some are selective (e.g. for beta-1 receptors and, thus mostly, impact the heart), but none are absolutely selective.

    List of Beta Blockers

    • Propranolol
    • Nadolol
    • Pindolol
    • Acebutolol
    • Metoprolol
    • Timolol
    • Atenolol
    • Labetalol

    Beta Blockers: Clinical Uses

    • Hypertension: Often combined with diuretics or vasodilators to achieve desired blood pressure control.

    • Ischemic Heart Disease: Reduce angina frequency, improve exercise tolerance.

    • Cardiac Arrhythmias: Treatment of both supraventricular and ventricular arrhythmias.

    • Glaucoma: Topical application reduces intraocular pressure by preventing aqueous humor production

    Beta Blockers: Metabolic and Endocrine Effects

    • Inhibits lipolysis.

    • Use with caution in diabetics due to potential impact on glycogenolysis in the liver.

    Beta Blockers: Eye Effects

    • Decrease intraocular pressure for managing open-angle glaucoma.

    Beta Blockers: Other Uses

    • Hyperthyroidism: Excess hormone production leads to elevated epinephrine (EP) and norepinephrine (NE) levels, which these drugs can help mitigate.

    • Neurologic Disease: Propranolol has some use to manage migraine episodes.

    Beta Blockers: Agonists: Clinical Uses

    • Epinephrine (EP): Used in severe allergic reactions (anaphylactic shock) and for cardiac arrest, sometimes alongside local anesthetics.

    • Beta-2 agonists: Used in asthma inhalers; Phenylephrine: nasal decongestant.

    Beta Blockers: Antagonists: Clinical Uses

    • Prazosin (Alpha-1 blocker): Hypertension
    • Phenoxybenzamine (Non-selective alpha blocker): Pheochromocytoma
    • Atenolol, Metoprolol, Propranolol: Hypertension
    • Timolol: Anti-glaucoma agents (eye drops)

    Beta Blockers: Additional Details

    • Well absorbed after oral administration.

    • F (fractional) of drug absorption varies widely, with some experiencing first-pass effects.

    • Most drugs cross the blood-brain barrier (BBB) due to their lipophilic nature.

    • Genetic variation in CYP 2D6 enzyme can impact drug response.

    Beta Blockers: CNS Effects

    • CNS effects, including sedation, sleep disturbance, and depression may be seen particularly with non-selective beta blockers.

    • Nonselective drugs block Beta 2 receptors in the lungs, worsening asthma conditions.

    • Beta blockers may worsen cardiac function in individuals with pre-existing heart disease.

    • Exacerbation of hypoglycemia in insulin-dependent patients is a potential concern with beta blocker use.

    Summary of Antagonist Clinical Uses and Classification

    • Uses of antagonists, including alpha and beta antagonists.
    • Pheochromocytoma treatment.
    • Reversible versus irreversible antagonists.
    • Alpha and beta antagonist drugs.
    • Clinical uses for alpha blocker drugs.
    • Clinical uses for beta blocker drugs.
    • Clinical uses for the antagonists.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    PM716 Pharmacology I - NE Blockers PDF

    Description

    Explore the critical concepts of NE blockers and their clinical applications in this quiz. Delve into the case studies involving patients with pheochromocytoma and understand the use of sympatholytics in managing adrenergic receptor antagonism. Test your knowledge on pharmacological interventions and the role of these drugs in the peripheral nervous system.

    More Like This

    Neon He-Ne Laser Quiz
    3 questions

    Neon He-Ne Laser Quiz

    He-Ne Lasers
    6 questions

    He-Ne Lasers

    StimulatingNovaculite avatar
    StimulatingNovaculite
    Monthly Meeting NE
    26 questions

    Monthly Meeting NE

    PrudentHazel avatar
    PrudentHazel
    NE Agonists
    45 questions

    NE Agonists

    FelicitousCognition avatar
    FelicitousCognition
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser