III. 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

IV. 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

V. 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

VI. Drug Interaction

  1. Increases Digitalis (Digoxin) level
  2. Beta Blocker (see contraindications above)

VII. Pharmacokinetics

  1. Peak effect seen within 3-5 minutes of bolus injection

VIII. 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)

IX. 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

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Cost: Medications

VERAPAMIL (on 2/19/2015 at Target.com)
VERAPAMIL 120 MG Tablet #90 for $10.00 $0.11 each
VERAPAMIL 80 MG Tablet #90 for $10.00 $0.11 each
verapamil (on 8/17/2016 at Medicaid.Gov Survey of pharmacy drug pricing)
VERAPAMIL 120 MG TABLET Generic $0.08 each
VERAPAMIL 360 MG CAP PELLET Generic $3.14 each
VERAPAMIL 40 MG TABLET Generic $0.14 each
VERAPAMIL 80 MG TABLET Generic $0.06 each
VERAPAMIL ER 120 MG CAPSULE Generic $1.29 each
VERAPAMIL ER 120 MG TABLET Generic $0.21 each
VERAPAMIL ER 180 MG CAPSULE Generic $1.37 each
VERAPAMIL ER 180 MG TABLET Generic $0.15 each
VERAPAMIL ER 240 MG CAPSULE Generic $1.61 each
VERAPAMIL ER 240 MG TABLET Generic $0.15 each
VERAPAMIL ER PM 100 MG CAPSULE Generic $0.97 each
VERAPAMIL ER PM 200 MG CAPSULE Generic $1.33 each
VERAPAMIL ER PM 300 MG CAPSULE Generic $1.69 each
VERAPAMIL SR 120 MG CAPSULE Generic $1.29 each
VERAPAMIL SR 180 MG CAPSULE Generic $1.37 each
VERAPAMIL SR 240 MG CAPSULE Generic $1.61 each
calan (on 6/1/2016 at Medicaid.Gov Survey of pharmacy drug pricing)
CALAN SR 240 MG CAPLET Generic $0.15 each

Ontology: Verapamil (C0042523)

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)
Definition (CSP) calcium channel blocker that dilates coronary arteries and decreases myocardial oxygen demand.
Definition (MSH) A calcium channel blocker that is a class IV anti-arrhythmia agent.
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)
Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH D014700
SnomedCT 372754009, 47898004
LNC LP16307-8, MTHU007771
English Iproveratril, Verapamil, Benzeneacetonitrile, alpha-(3-((2-(3,4-dimethoxyphenyl)ethyl)methylamino)propyl)-3,4-dimethoxy-alpha-(1-methylethyl)-, alpha-[3-[[2-(3,4-Dimethoxyphenyl)ethyl]methylamino]propyl]-3,4-dimethoxy-alpha-(1-methylethyl)benzeneacetonitrile, verapamil (medication), Verapamil [Chemical/Ingredient], VERAPAMIL, verapamil, Verapamil (product), Verapamil (substance)
Swedish Verapamil
Czech verapamil
Finnish Verapamiili
Russian VERAPAMIL, IPROVERATRIL, ВЕРАПАМИЛ, ИПРОВЕРАТРИЛ
Japanese 塩酸ベラパミル, ワソラン, ホルミトール, 塩酸イプロベラトリル, ベラパミル塩酸塩, マゴチロン, カラン, ロシトール, イプロベラトリル, ベラパミル
Croatian Not Translated[Verapamil]
French Iprovératril, Vérapamil
Polish Werapamil
Spanish ipoveratrilo, verapamilo (producto), verapamilo (sustancia), verapamilo, Iproveratril, Verapamilo
German Iproveratril, Verapamil
Italian Verapamil
Portuguese Iproveratril, Verapamil

Ontology: Phenylalkylamine (C0597214)

Concepts Organic Chemical (T109)
SnomedCT 406766008
English phenylalkylamine, Phenylalkylamine (substance), Phenylalkylamine
Spanish fenilalquilamina (sustancia), fenilalquilamina

Ontology: Calan (C0700935)

Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH D014700
English calan, Calan