Pharmacology for Midwifery: ANS Drugs
24 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

Which muscarinic receptor subtype is primarily linked to a decrease in the heart's contraction rate and force?

  • M3
  • M5
  • M1
  • M2 (correct)
  • What physiological effect is associated with the stimulation of M3 muscarinic receptors?

  • Increased heart rate
  • Pupil dilation
  • Increased gastrointestinal motility (correct)
  • Bronchodilation
  • Which receptors are predominantly associated with mediating higher cerebral functions?

  • M3
  • M1
  • M4 and M5 (correct)
  • M2
  • What is a common adverse effect of activating muscarinic receptors?

    <p>Bronchoconstriction (D)</p> Signup and view all the answers

    Which of the following substances is a direct-acting muscarinic agonist?

    <p>Acetylcholine (B)</p> Signup and view all the answers

    Which indirect-acting cholinergic agent stimulates the release of acetylcholine?

    <p>Cisapride (D)</p> Signup and view all the answers

    Which effect does stimulation of muscarinic receptors NOT cause?

    <p>Pupil dilation (B)</p> Signup and view all the answers

    Which tissues are M1 receptors primarily found?

    <p>Postganglionic neurons and parietal cells (D)</p> Signup and view all the answers

    What type of receptors respond to nicotine stimulation?

    <p>Nicotinic receptors (B)</p> Signup and view all the answers

    Where are nicotinic receptors primarily located?

    <p>Centrally and at autonomic ganglia (C)</p> Signup and view all the answers

    What is a common adverse effect of nicotine stimulation?

    <p>Increased blood pressure (D)</p> Signup and view all the answers

    Which of the following describes muscarinic receptors?

    <p>They are both central and peripheral. (D)</p> Signup and view all the answers

    What are common side effects of nicotine patches?

    <p>Skin reactions like itching and burning (D)</p> Signup and view all the answers

    Why is nicotine therapy contraindicated in pregnancy?

    <p>It has many cardiovascular effects. (D)</p> Signup and view all the answers

    What is NOT a typical effect of stimulating nicotinic receptors?

    <p>Enhancement of parasympathetic activity (B)</p> Signup and view all the answers

    Which chemical is specifically associated with muscarinic receptors?

    <p>Muscarine (C)</p> Signup and view all the answers

    What conditions can be treated with anticholinergic agents?

    <p>Mydriasis and glaucoma (C)</p> Signup and view all the answers

    What is the primary mechanism of action of anticholinesterases?

    <p>Reversing acetylcholine degradation (C)</p> Signup and view all the answers

    Which of the following is a common adverse effect of anticholinesterases?

    <p>Bradycardia (B)</p> Signup and view all the answers

    Which agent is a very short-acting anticholinesterase?

    <p>Edrophonium (C)</p> Signup and view all the answers

    Why is atropine or propantheline administered with anticholinesterases?

    <p>To minimize muscarinic adverse effects (C)</p> Signup and view all the answers

    In which condition should medications for myasthenia gravis be taken early in the day?

    <p>Because muscle weakness is more severe in the morning (B)</p> Signup and view all the answers

    What can an overdose of anticholinesterases lead to?

    <p>Cholinergic crisis (D)</p> Signup and view all the answers

    Which of the following does NOT describe anticholinergic agents?

    <p>They enhance acetylcholine action. (C)</p> Signup and view all the answers

    Study Notes

    Pharmacology for Midwifery

    • This is a pharmacology course for midwives.

    Drugs Affecting the Autonomic Nervous System (ANS)

    • The autonomic nervous system (ANS) controls involuntary body functions.
    • It has two divisions:
      • Sympathetic (fight-or-flight)
      • Parasympathetic (rest-and-repose)
    • ANS pathways use preganglionic and postganglionic fibers.
    • The target tissue is called an effector.
    • Key neurotransmitters are acetylcholine and noradrenaline.
      • Cholinergic fibers release acetylcholine, and their receptors are cholinergic.
      • Adrenergic fibers release noradrenaline, and their receptors are adrenergic
    • Neuromodulators can alter nerve and tissue responses.

    Cholinergic Division

    • Two main subtypes of cholinergic receptors:

      • Nicotinic receptors: respond to nicotine
      • Muscarinic receptors: respond to muscarine
    • Both receptor types are activated by acetylcholine, but have structural differences.

    Nicotinic Receptors

    • Located in autonomic ganglia and neuromuscular junctions of skeletal muscles.
    • Effects of stimulation include:
      • Behavioral changes (relaxation, well-being)
      • Increased autonomic tone (both sympathetic and parasympathetic)
      • Adrenaline and noradrenaline release from the adrenal medulla
      • Increased skeletal muscle tone

    Common Adverse Effects (Nicotine)

    • At doses absorbed during smoking, nicotine is a peripheral stimulant (mostly cardiovascular).
    • Nicotine treatment for quitting mimics these effects.
    • Potential adverse effects: cardiovascular stimulation, headaches, nausea, insomnia, skin reactions (itching, burning, redness).
    • Contraindications: pregnancy, lactation, hypersensitivity, serious cardiovascular conditions (e.g., acute MI, unstable angina, recent stroke, dysrhythmia).

    Muscarinic Receptors

    • Located centrally and peripherally on effectors stimulated by cholinergic nerves (most parasympathetic and some sympathetic).
    • Located on various peripheral tissues, including iris, sweat glands, lacrimal glands, digestive glands, myocardium, bronchioles, gastrointestinal tract, urinary tract, liver, sex organs, blood vessels (skin, genitalia, and skeletal muscle).

    Mechanism of Action (Muscarinic Receptors)

    • Five distinct functional subtypes (M1, M2, M3, M4, M5).
    • M1 and M3 receptors are primarily located within the brain and mediate higher brain functions; reduction in receptor numbers within the cortex has been linked to Alzheimer's disease.
    • M1 receptors are also located peripherally (stomach) and stimulate acid secretion.
    • M2 receptors are in the myocardium and reduce heart rate and contraction strength when stimulated.
    • M3 receptors are associated with visceral smooth muscle and exocrine glands
    • Stimulate various parasympathetic responses, including pupil constriction, increased GI motility and secretion, increased bronchial mucus secretion etc

    Common Adverse Effects (Muscarinic Receptors)

    • Common adverse effects include bradycardia, hypotension, pupil constriction, sweating, bronchoconstriction, drooling, diarrhea.
    • Contraindications include intestinal and urinary obstruction.

    Cholinergic Agonists (Direct Acting)

    • Include acetylcholine, bethanechol, carbachol, and pilocarpine
    • Stimulate acetylcholine release

    Cholinergic Agonists (Indirect Acting)

    • Example: Cisapride
    • Stimulates acetylcholine release from myenteric plexus.

    Anticholinesterases (Mechanism of Action)

    • Inhibit acetylcholine metabolism (cholinesterase)
    • Prolong the action of acetylcholine

    Common Adverse Effects (Anticholinesterases)

    • Common adverse effects: pupil constriction, hypotension, bradycardia, diarrhea, muscle twitching, bronchoconstriction, increased lacrimation, sweating.

    Anticholinesterases (Drugs)

    • Donepezil, galantamine, pyridostigmine, neostigmine, physostigmine.
    • Edrophonium (very short-acting).
    • Use in reversal of neuromuscular blockers (with atropine or propantheline to minimize muscarinic effects)

    Myasthenia Gravis (Considerations)

    • Medications for myasthenia gravis should be taken early in the day.
    • Overdose on anticholinesterase can lead to a cholinergic crisis.
      • Excessive sweating, defecation, urination, miosis, salivation, bradycardia, muscle weakness.

    Nicotinic Antagonists

    • Used as ganglionic and neuromuscular blocking agents.
    • Used in surgery, blood pressure issues, trauma cases

    Depolarizing Neuromuscular Blocking Agents (e.g., Succinylcholine)

    • Acts as an acetylcholine agonist at nicotinic receptors.
    • Action is sustained, preventing repolarization and leading to paralysis.
    • Causes muscle fasciculations which are immediately followed by flaccidity,

    Non-Depolarizing Neuromuscular Blocking Agents (e.g., Atracurium)

    • Antagonistic towards acetylcholine
    • Block receptors to cause complete paralysis without fasciculation
    • Reversed by giving acetylcholine increasing agents (eg. neostigmine)

    Muscarinic Antagonists

    • Block muscarinic receptors.
    • Also known as anticholinergic drugs/ antimuscarinic drugs.
    • Include atropine, hyoscine, scopolamine, glycopyrrolate, ipratropium, etc
    • Common adverse effects include blurred vision, dry mouth, constipation, blurred vision, and tachycardia

    Uses of Muscarinic Antagonists

    • Antispasmodics (treating spasms)
    • Antiulcerants (reducing gastric acid secretion)
    • Antiemetics
    • Antidysrhythmics
    • Mydriatics and cycloplegics
    • Premedication for anesthesia
    • Bronchodilators
    • Treatment for urinary frequency, enuresis, and incontinence.

    Studying That Suits You

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

    Quiz Team

    Related Documents

    Pharmacology for Midwifery PDF

    Description

    Explore the pharmacology of drugs affecting the autonomic nervous system in this midwifery course. Delve into the roles of sympathetic and parasympathetic divisions, key neurotransmitters, and the functionalities of cholinergic and adrenergic receptors. Enhance your understanding of this critical subject in midwifery care.

    More Like This

    Use Quizgecko on...
    Browser
    Browser