ANTIDYSRHYTHMICS

·         Prevents dysrhythmias by inhibiting abnormal pathways of electrical conduction to the heart

·         Indication:

o    Prevention of cardiac dysrhythmias

·         Contraindication:

o    Liver disorder, heart failure, cardiogenic shock, second or third heart block

Examples:

Class I

Fast (Sodium) Channel Blockers I

o    disopyride (Norpace^®, Napamide^®)

o    procainamide (Procan^®, Pronestyl^®)

o    quinidine, pylogalacturonate, gluconate (Quinidex^®, Cardioquin^®)

Fast (Sodium) Channel Blockers IB

o    lidocaine (Xylocaine^®)

o    mexiletine (Mexitil^®)

o    tocainide (Tonocard^®)

Fast (Sodium) Channel Blockers IC

o    flecainide (Tambocor^®)

o    propafenone (Rythmol^®)

Other Class I

o    moricizine (Ethmozine^®)

Class II

Beta-Adrenergic Blockers

o    acebutolol (Sectral^®)

o    esmolol (Brevibloc^®)

o    propanolol (Inderal^®)

Class III

Prolong Repolarization

o    adenosine (Adenocard^®)

o    amiodarone (Cordarone^®)

o    bretylium tosylate (Bretylol^®)

o    dofetilide (Tikosyn^®)

o    sotalol (Betapace^®)

Class IV

Calcium Channel Blockers

o    verapamil (Calan^®, Isoptin^®)

o    diltiazem (Cardizem^®)

Others

o    phenytoin (Dilantin^®)

o    digoxin (Lanoxin^®)

o    ibutilide fumarate (Corvert^®)

 Side Effects:

·         Quinidine: nausea and vomiting, diarrhea, confusion and hypotension, heart block, neurologic and psychiatric symptoms

·         Procainamide: less cardiac depression than quinidine

·         Lidocaine, mexiletine and tocainide:cardiovascular depression, bradycardia, hypotension, seizures, blurred vision and double vision

·         Beta-blockers: bradycardia and hypotension

·         Bretylium and amiodarone: nausea and vomiting, hypotension and neurologic problems

·         Calcium channel blockers: nausea and vomiting, hypotension, bradycardia

·         Adenosine frequently causes asystole for a few seconds however this adverse effect effect is short lived as the drug has an extremely short half life and effect may last less than a minute.

Nursing Considerations:

ü  Monitor vital signs. Hypotension can occur.

ü  Administer drug as prescribed.

ü  Monitor ECG and report abnormal patterns.

ü  Provide patient teachings:

o    Provide specific instructions for each drug and instruct patient that drug compliance is essential.

o    Instruct the patient to report side effects.

o     Advise patient to avoid the following:

§  Alcohol- can increase hypotensive reaction

§  Caffeine- increases catecholamine level

§  Tobacco- promotes vasoconstriction