Download Verapamil (Liverpool)

Liverpool Hospital
Drug Guideline
ICU: Pharmacology
Verapamil
Intensive Care Unit
Verapamil
Summary: Verapamil is a calcium ion influx inhibitor which can be used to lower
raised blood pressure and as an antiarrhythmic for supraventricular
tachycardia.
Approved by:
ICU Medical Director
Publication (Issue) Date:
April 2013
Next Review Date:
April 2016
Replaces Existing Drug Guideline: June 2007
Previous Review Dates:
November 2003
1. Introduction::
Patient safety
The Aims / Expected Outcome of this drug guideline:
Verapamil will be administered safely and appropriately without any adverse
side effects
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Related Policies
C3.00 Drug prescribing
C3.01 Drug administration
C3.01 Administration of IV Medications
2. Drug Guideline: Policy Statement
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All care provided within Liverpool Hospital will be in accordance with infection
control, manual handling and minimisation and management of aggression
guidelines.
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Medications are to be prescribed and signed by a medical officer/authorised
nurse practitioner (NP) unless required during an emergency.
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All drugs administered during an emergency (under the direction of a medical
officer/authorised nurse practitioner) are to be documented during the event,
then prescribed and signed following the event.
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Medications are to be given at the time prescribed (as close to the time as is
possible when multiple drugs require ‘same time’ administration and, when the
nurse is caring for more than one patient, recognition is given to a possible short
delay to administration – antibiotics and other lifesaving drugs are to be
prioritised) and are to be signed by the administering nurse.
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Parenteral medication prescriptions and the drug are to be checked with a
second registered or endorsed enrolled nurse prior to administration. The “rights
of drug administration” must be followed: right: patient, drug, dose, route,
administration, time, reason for the drug, documentation, education and
evaluation/outcome.
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Liverpool Hospital
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3.
ICU: Pharmacology
Verapamil
Intensive Care Unit
Adverse drug reactions are to be documented and reported to a medical officer.
Medication errors are to be reported using the hospital electronic reporting
system: IIMS.
Guidelines are for adult patients unless otherwise stated
Guideline
Actions
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Verapamil is a calcium channel blocker affecting vascular smooth muscle,
myocardial contractility and cardiac conduction via the A-V node.
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It acts by inhibiting calcium ion influx across the cell membrane of the arterial
smooth muscle as well as in conductile and contractile myocardial cells.
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It prolongs impulse conduction in the atrioventricular node and thus depending
on the type of arrhythmia, restores the sinus rhythm and normalises the
ventricular rate.
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It reduces myocardial oxygen consumption directly by intervening in energy
consuming metabolic processes of the myocardial cell (reducing heart rate and
contractility) and indirectly by diminishing the peripheral resistance (afterload).
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The decrease of vascular smooth muscle tone prevents coronary spasms and
lowers raised blood pressure.
Indications.
• Supraventricular Tachycardia.
• Acute Hypertension
• Management of vasospasm associated with artery grafts used in coronary
bypass surgery.
Contraindications
• Hypersensitivity.
• Wide QRS tachycardia (where there is any doubt as to whether the rhythm is VT
or SVT with aberrant conduction).
• Complicated acute myocardial infarction (bradycardia, hypotension, left
ventricular failure)
• Ventricular dysrhythmias.
• Concomitant use with beta-blockers: may cause heart block and asystole.
• Hypotension.
• Pulse rate < 50.
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• Any evidence of 2 or 3 degree heart block.
• Patients with AF or AF with Wolff-Parkinson-White syndrome, these patients are
at risk of ventricular tachycardia or ventricular fibrillation if verapamil is
administered.
Precautions
• Severe hypotension can occur with rapid administration. It should be given as
slow IV injection and promptly discontinued if severe hypotension occurs.
• As it slows conduction via the AV node it can lead to second or third degree AV
block (especially in patients with sick sinus syndrome).
• Use with caution in patients with hepatic failure, because the effect is intensified
and prolonged depending on the disease severity.
• In patients with renal disease - observe for abnormally prolonged PR intervals,
indicating excessive effect.
• Should not be used in the first and second trimester of pregnancy and only later
with regard to maternal hypotension and foetal hypoxia.
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Liverpool Hospital
ICU: Pharmacology
Verapamil
Intensive Care Unit
Significant interactions
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Beta-Blockers - increased risk of bradyarryhmias, heart block and asystole,
especially in patients with cardiomyopathy, congestive heart failure or recent
myocardial infarction.
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Antihypertensives, diuretics, vasodilators potentiate the hypertensive effects.
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Digoxin, cyclosporin - increases the plasma levels of these drugs.
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Carbemazepine – it potentiates the effect and enhances risk of neurotoxicity
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Non-depolarising muscle relaxants – there is a risk of prolonged action when
they are administered with verapamil.
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Lithium – increased sensitivity to the effects of lithium with risk of neurotoxicity.
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Quinidine, amiodarone, procainamide, flecainide, disopyramide - increased risk
of heart failure, bradycardia, and proarrhythmic effect.
Adverse effects
• Hypotension.
• Bradycardia and first or second degree AV block.
• Headache, dizziness, flushing, nausea.
Presentation
Verapamil 5mg in 2mL ampoule.
Administrations Guidelines
Management of supraventricular tachycardia:
• Dilute 5mg verapamil in 10mL sterile 0.9% sodium chloride (0.5mg/mL).
• Administer verapamil 1mg/minute IV slow bolus until heart rate slows, may be
repeated once in the next in five to ten minutes for tachyarrhythmias and
hypertension.
Post radial artery graft and bilateral internal mammary artery graft used in
coronary bypass surgery:
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Dilute verapamil 10mg in 50mL sterile 0.9% sodium chloride (to give a
concentratio = 0.2mg/ml).
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Infuse at a rate of 0.2micrograms/kg/minute
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Example for patient weighing 70kg
= 14micrograms /min
= 840micrograms /hour
= 0.84mg/hour
= 4.2mL/hr.
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Continue infusion postoperatively until the morning of Day 1.
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Administer Diltiazem orally. Use Diltiazem 30mg tds if SBP < 120mmHg OR
Diltiazem CD 180mg once daily if SBP ≥ 120mmHg. Use clinical judgement to
decide which is the most appropriate dose.
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4 hours post oral diltiazem, cease verapamil infusion.
Clinical Considerations
 ECG and blood pressure monitoring is necessary for patients receiving
intravenous verapamil.
 Severe hypotension as a result of administration should be treated with
vasoconstrictors.
 Second or third AV block if it occurs should be treated with atropine, isoprenaline
or external pacing.
4. Performance Measures
All incidents are documented using the hospital electronic reporting system: IIMS and
managed appropriately by the NUM and staff as directed.
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Liverpool Hospital
ICU: Pharmacology
Verapamil
Intensive Care Unit
5. References / Links
1. MIMS Online, CIAP: NSW Health Department, Copyright MIMS Australia Pty Ltd.
February 2012. http://www.use.hcn.com.au
2. The Society of Hospital Pharmacists of Australia 2007, The Australian Injectable Drugs
th
Handbook, 4 Edition, SHPA publications, Australia.
3. eTherapeutic Guidelines: CIAP 2012, http://www.tg.org.au/
th
4. Thomas Reuters, Micromedex 2.0, http://www.micromedex.com/, viewed 13 March
2012.
Author:
Reviewers:
CNC (S.Shunker)
ICU Director, ICU – NM, NUM, ICU – CNE, ICU – CNS,
Pharmacist.
Endorsed by:
A Proff Michael Parr, ICU Director
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