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VerapamilAka: Calan, Phenylalkamine

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  1. Class
    1. Calcium Channel Blocker
  2. Mechanism
    1. AV Node effects
      1. Slow AV Node Conduction
      2. Prolong AV Node refractory period
    2. Reduces myocardial oxygen consumption
      1. Negative chronotropic effect
      2. Negative inotropic effect
    3. Reduces Systemic Vascular Resistance
      1. Results from vasodilatation of vascular smooth muscle
      2. Counters negative inotropic effect
    4. More negative hemodynamic effects than Diltiazem
    5. Coronary vasodilatation
  3. Contraindications
    1. Wolff-Parkinson-White Syndrome with Atrial Fibrillation
      1. Paroxysmal accelerated ventricular response
      2. Risk of progression into Ventricular Fibrillation
    2. Wide Complex Tachycardia (unless supraventricular)
      1. Risk of severe hypotension
      2. May progress into Ventricular Fibrillation
      3. Verapamil ineffective against Ventricular Tachycardia
    3. Sinus Node or AV Node dysfunction without Pacemaker
      1. AV Block
      2. Sick Sinus Syndrome
    4. Severe Congestive Heart Failure
    5. Concurrent Intravenous Beta Blocker use
  4. Indications
    1. Paroxysmal Supraventricular Tachycardia (90% effective)
      1. Terminates sustained reentry within AV Node
      2. Terminates AV Node limb of reentrant circuit
    2. Supraventricular Tachycardia
      1. Terminates AV Node reentry tachycardias
      2. Slows ventricular response to Atrial Fibrillation
      3. Verapamil is highly effective
      4. Used for acute treatment and prevention
    3. Hypertension
  5. Drug Interaction
    1. Increases Digitalis (Digoxin) level
    2. Beta Blocker (see contraindications above)
  6. Pharmacokinetics
    1. Peak effect seen within 3-5 minutes of bolus injection
  7. Dosing
    1. Supraventricular Tachycardia
      1. Adults
        1. Initial Dose: 2.5 to 5.0 mg IV bolus over 3 min
        2. Subsequent: 5 mg IV every 15 min (Max 30 mg total)
      2. Children (8-15 years old)
        1. Initial: 0.1 mg/kg up to 2.5 mg IV over 1-2 min
        2. Subsequent: 0.2 mg/kg up to 5 mg after 15 min
    2. Hypertension
      1. Regular: 80 mg PO tid (MAX 360 mg/day)
      2. Extended: 240 mg PO qd (MAX 480 mg/day)
  8. Precautions: Transient Hypotension
    1. Results from peripheral vasodilation
    2. Countered by Intravenous Calcium Injection
    3. Consider prophylactic pretreatment with Calcium
      1. Marginal Blood Pressure
      2. Left Ventricular Dysfunction

Verapamil (C0042523)

Definition (MSH)A calcium channel blocker that is a class IV anti-arrhythmia agent.
Definition (CSP)calcium channel blocker that dilates coronary arteries and decreases myocardial oxygen demand.
Definition (PDQ)A phenylalkylamine calcium channel blocking agent. Verapamil inhibits the transmembrane influx of extracellular calcium ions into myocardial and vascular smooth muscle cells, causing dilatation of the main coronary and systemic arteries and decreasing myocardial contractility. This agent also inhibits the drug efflux pump P-glycoprotein which is overexpressed in some multi-drug resistant tumors and may improve the efficacy of some antineoplastic agents. Check for "http://www.cancer.gov/Search/ClinicalTrialsLink.aspx?id=39730&idtype=1" active clinical trials or "http://www.cancer.gov/Search/ClinicalTrialsLink.aspx?id=39730&idtype=1&closed=1" closed clinical trials using this agent. ("http://nciterms.nci.nih.gov:80/NCIBrowser/ConceptReport.jsp?dictionary=NCI_Thesaurus&code=C928" NCI Thesaurus)
Definition (NCI)A phenylalkylamine calcium channel blocking agent. Verapamil inhibits the transmembrane influx of extracellular calcium ions into myocardial and vascular smooth muscle cells, causing dilatation of the main coronary and systemic arteries and decreasing myocardial contractility. This agent also inhibits the drug efflux pump P-glycoprotein which is overexpressed in some multi-drug resistant tumors and may improve the efficacy of some antineoplastic agents. (NCI04)
ConceptsOrganic Chemical (T109) , Pharmacologic Substance (T121)
MSHD014700
EnglishIproveratril, Verapamil, VERAPAMIL PREPARATION
Spanishipoveratrilo, verapamilo
Parent ConceptsOrganic nitrogen compound (C0576728), Phenethylamines (C0031399), Coronary vasodilator (C0596385), Calcium Channel Blockers (C0006684), Anti-Arrhythmia Agents (C0003195), [CV250] ANTIANGINALS (C0724739), Class IV antiarrhythmic drug (C0360706), Phenylalkylamine (C0597214), Calcium Channel Blocking Agents (Non-dihydropyridines) (C1579438)
SourcesAOD, CSP, LNC, MSH, NCI, NDFRT, PDQ, RXNORM, SCTSPA, SNOMEDCT, USPMG, VANDF
Derived from the NIH UMLS (Unified Medical Language System)


Calan (C0700935)

ConceptsOrganic Chemical (T109) , Pharmacologic Substance (T121)
MSHD014700
EnglishCalan
SourcesMSH, NCI, RXNORM
Derived from the NIH UMLS (Unified Medical Language System)



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