Antiarrhythmics

Section 8 - MEDICATION GUIDELINES

8.06 ANTIARRHYTHMICS

Adenosine (ADENOCARD) / Antiarrhythmic

DESCRIPTION/ACTION:

• It is a natural occurring agent that can "chemically cardiovert" Paroxysmal Supraventricular Tachycardia (PSVT) to a normal sinus rhythm.
• It has a half-life of 5 seconds and does not cause hypotension like Verapamil.
• Restores normal sinus rhythm by interrupting re-entrant pathways in the AV node.
• Slows conduction time through the AV node.
• Produces coronary artery vasodialation.

INDICATIONS:

• Narrow complex (PSVT) refractory to vagal maneuvers.

CONTRAINDICATIONS:

• 2nd and 3rd Degree Heart Block, Sick Sinus Syndrome, or known hypersensitivity to the medication.

PRECAUTIONS:

• It may cause transient arrhythmias.
• It may cause bronchospasm in asthma patients.
• Heart transplant patients may only require a smaller dosage and patients on Theophylline based medications may require larger dosage, contact MEDICAL CONTROL for consult.

DOSAGE:

• IV 6 mg by rapid IV bolus, if no results repeat 1-2 minutes later as 12 mg rapid IV bolus. Maximum total dose 18 mg.
• Pediatrics - Refer to Handtevy System for patient specific dosage
  • Premies - 13 y/o: 0.1 mg/kg (1st dose), 0.2 mg/kg (2nd dose)

Atropine Sulfate / ANTIMUSCARINICS / ANTIDOTES

DESCRIPTION / ACTION:

• It blocks the parasympathetic nervous system and it’s inhibiting effects on heart rate.
• It does not increase the strength of cardiac contraction.

INDICATIONS:

• Symptomatic Bradycardia, Asystole if clinically indicated (vagally induced), and Organophosphate Poisoning.

CONTRAINDICATIONS:

• None in the emergency setting.

PRECAUTIONS:

• Give no more than 3.0 mg for cardiac-related problems. May cause a decrease in ventricular rate in the presence of 2nd Degree Mobitz II and 3rd Degree Heart Block.

DOSAGE:

• 0.5 mg - 1.0 mg IVP AND refer to appropriate PRACTICE PARAMETER for specific dosage.
• Refer to Handtevy System for pediatric specific dosage.

Lidocaine 2% (XYLOCAINE) / Antidysrrhythmic

DESCRIPTION:

• Lidocaine is an agent that increases the fibrillation threshold thereby reducing the development of ectopy and Ventricular Fibrillation.

INDICATIONS:

• More than 6 unifocal PVCs / minute, multifocal PVCs, R on T phenomenon, couplets, runs of PVCs, Ventricular Tachycardia, and in V-Fib/Pulseless Ventricular Tachycardia.
• May be used to enhance RSI in head injuries and may be useful in seizures caused by head injuries.

CONTRAINDICATIONS:

• 2nd degree Mobitz II and 3rd Degree Heart Blocks and bradycardias.

PRECAUTIONS:

• Side effects include: lowering LOC, confusion, irritability, muscle spasm, seizures, coma and possibly death.

DOSAGE:

• 0.5 - 1.5 mg / kg AND refer to appropriate PRACTICE PARAMETER for specific dosages.
• Refer to Handtevy System for pediatric specific dosage.

Diltiazem (CARDIZEM) / Calcium Channel Blocker

DESCRIPTION:

• Slows conduction through the SA / AV node, Causes vasodilation.

INDICATIONS:

• ATRIAL FIBRILLATION, ATRIAL FLUTTER. PRACTICE PARAMETER (4.03)

CONTRAINDICATIONS:

• HYPOTENSION, wide complex tachycardia, conduction system disturbances.

PRECAUTIONS:

• CHF, Hypotension, renal disease.

DOSAGE:

• 0.25 mg/kg IV bolus over 2 minutes AND refer to appropriate PRACTICE PARAMETERS for specific dosages.

Amiodarone / Antiarrhythmic

DESCRIPTION:

• Class III antidysrhythmic that prolongs the cardiac action potential and repolarization phase of the cardiac cycle. It shows beta-blocker and potassium channel blocker properties thus reducing dysrhythmias. It has complex drug effects on sodium and potassium.

INDICATIONS:

• Ventricular Fibrillation, Pulseless V-Tach (4.08), V-Tach with a pulse (4.09).

CONTRAINDICATIONS:

• Sinus bradycardia, AV blocks.

PRECAUTIONS:

• Not recommended for pregnant or nursing mothers.
• Multiple drug interactions – interacts with digoxin, warfarin, phenytoin.
• When given concurrently with simvastatin (cholesterol drugs) it increases the risk for rhabdomyolysis and renal failure.

DOSAGE:

• Adult
  • VF/VT – 300 mg IVP, IO. May repeat once with 150 mg IVP, IO if dysrhythmia is not suppressed with initial dose.
  • VT with a pulse – 150 mg diluted in 50 ml (Buretrol) over 10 minutes.
• Pediatric - Refer to Handtevy System for pediatric specific dosage.
  • VF/VT - 5 mg/kg, can repeat dose in 5 mg/kg doses to max of 15 mg/kg total dose.