Calcium Channel Blockers Mechanism of Action
13 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 the primary mechanism of action of calcium channel blockers?

  • Increasing the contraction of cardiac muscle
  • Enhancing the contraction of vascular smooth muscle
  • Blocking the influx of calcium ions into vascular smooth muscle cells and cardiac cells (correct)
  • Reducing the frequency of the heart's contractions

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

  • Increased peripheral resistance
  • Dizziness or lightheadedness (correct)
  • Tachycardia
  • Hypertension

    • What is a rare but serious adverse effect of calcium channel blockers?

  • Angioedema (correct)
  • Bradycardia
  • Peripheral vasoconstriction
  • Hypertension

    • What is the effect of calcium channel blockers on cardiac muscle?

    <p>Inhibit the contraction of cardiac muscle</p> Signup and view all the answers

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

    <p>Gastrointestinal disturbances</p> Signup and view all the answers

    What is the overall effect of calcium channel blockers on blood pressure?

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

    Which type of calcium channels do calcium channel blockers primarily block?

    <p>L-type calcium channels</p> Signup and view all the answers

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

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

    Which class of calcium channel blockers is least commonly used?

    <p>Phenytoin-like analogs</p> Signup and view all the answers

    What is a therapeutic indication for calcium channel blockers besides hypertension?

    <p>Atrial fibrillation</p> Signup and view all the answers

    What is the primary enzyme responsible for metabolizing calcium channel blockers?

    <p>CYP3A4</p> Signup and view all the answers

    What is the effect of calcium channel blockers on vasodilation?

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

    What is the range of elimination half-life for calcium channel blockers?

    <p>2-12 hours</p> Signup and view all the answers

    Study Notes

    Calcium Channel Blockers

    Mechanism of Action

    • Calcium channel blockers (CCBs) work by blocking the influx of calcium ions into vascular smooth muscle cells and cardiac cells
    • This leads to:
      • Relaxation of vascular smooth muscle, causing vasodilation
      • Decreased peripheral resistance
      • Decreased blood pressure
    • CCBs also:
      • Inhibit the contraction of cardiac muscle, reducing cardiac output
      • Decrease the frequency of the heart's contractions
    • The combined effect is a decrease in blood pressure and a reduction in the workload on the heart

    Adverse Effects

    • Common adverse effects:
      • Dizziness or lightheadedness due to vasodilation
      • Headache
      • Flushing
      • Peripheral edema (swelling of the legs and ankles)
    • Less common adverse effects:
      • Bradycardia (slow heart rate)
      • Hypotension (low blood pressure)
      • Gastrointestinal disturbances (nausea, vomiting, diarrhea)
    • Rare but serious adverse effects:
      • Angioedema (severe allergic reaction)
      • Stevens-Johnson syndrome (severe skin and mucous membrane disorder)
      • Heart block (impaired heart rhythm)

    Calcium Channel Blockers

    Mechanism of Action

    • Block influx of calcium ions into vascular smooth muscle cells and cardiac cells
    • Result in relaxation of vascular smooth muscle, causing vasodilation
    • Decrease peripheral resistance
    • Decrease blood pressure
    • Inhibit contraction of cardiac muscle, reducing cardiac output
    • Decrease frequency of heart's contractions
    • Combined effect: decrease in blood pressure and reduction in heart's workload

    Adverse Effects

    • Common:
      • Dizziness or lightheadedness due to vasodilation
      • Headache
      • Flushing
      • Peripheral edema
    • Less common:
      • Bradycardia
      • Hypotension
      • Gastrointestinal disturbances
    • Rare but serious:
      • Angioedema
      • Stevens-Johnson syndrome
      • Heart block

    Calcium Channel Blockers (CCBs)

    Mechanism of Action

    • Inhibit influx of calcium ions into vascular smooth muscle cells and cardiac myocytes to reduce muscle contraction and vasodilation
    • Block L-type calcium channels to decrease contraction force of the heart and lower blood pressure

    Adverse Effects

    • Common: headache, dizziness, flushing, peripheral edema
    • Less common: bradycardia, AV block, hypotension, constipation
    • Rare: allergic reactions, Stevens-Johnson syndrome, lupus-like syndrome

    Classes of CCBs

    Dihydropyridines (DHPs)

    • Most commonly used CCBs
    • Examples: nifedipine, amlodipine, felodipine

    Phenylalkylamines

    • Less commonly used CCBs
    • Examples: verapamil, gallopamil

    Benzothiazepines

    • Less commonly used CCBs
    • Examples: diltiazem, clentiazem

    Therapeutic Indications

    • Hypertension (primary indication)
    • Angina pectoris
    • Supraventricular tachyarrhythmias (PSVT, atrial fibrillation)
    • Raynaud's phenomenon
    • Migraine prophylaxis

    Pharmacokinetics

    • Well absorbed from the GI tract, with varying bioavailability among CCBs
    • High protein binding (90-98%)
    • Metabolized by the liver via CYP3A4
    • Elimination half-life: 2-12 hours, depending on the CCB

    Studying That Suits You

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

    Quiz Team

    Description

    Learn about the mechanism of action of calcium channel blockers, including their effects on vascular smooth muscle cells and cardiac cells, and their impact on blood pressure and cardiac output.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser