lidocaine (Xylocaine)

amiodarone (Cordarone)

adenosine (Adenocard)

Antidysrhythmic: lidocaine (Xylocaine)

Classification and Uses

Class Ib - block sodium channel, delay repolarization, éAPD

Used to treat PVCs (with more than 6 at a time) and V-tach

Lidocaine (Xylocaine) treats only _ventricular_ dysrhythmias.

Class III - drugs whose principal effect on cardiac tissue is to é APD

Uses: V-tach or supraventricular (V fib and V flutter) and A fib

Amiodarone (Cordarone) treats both _atrial_ and _ventricular_ dysrhythmias.

Half-life: 8-10 sec

Causes transient asystolic pause

Class V - antidysrhythmic

Used to convert supraventricular tachycardia (SVT) to normal sinus rhythm

Antidysrhythmics are used to alter the action potential of cardiac cells (alter some aspect of myocardial conduction to prevent dysrhythmias), making them less responsive to intrinsic electrical stimuli.

Dysrhythmias 

(Any abnormality in cardiac automaticity or impulse conduction will result in some type of dysrhythmia)   

Class I – prolong depolarization, diminish mycocaridal excitation, depress conduction

Class III – alter repolarization (longer), slows HR

Treat fast heart rhythms

Often times used when nothing else has worked – have horrible AEs (pro-arhythmic – can cause lethal dysrhythmias)

Antidyrhythmics: lidocaine (Xylocaine

AEs

CNS toxicities like twitching, convulsions, confusion; respiratory depression or arrest

CV - Hypotension, bradycardia, and dysrhythmias

Antidysrhythmics: amiodarone (Cordarone)

AEs

 Lipophilic – penetrates and concentrates the adipose tissue where it produces unwanted effects (any fatty tissue of the body)

Hyper/hypothyroidism, corneal micro deposits: halos, photophobias and dry eyes

Pulmonary toxicity (progressive dyspnea and cough accompanied by damage to alveoli) – can result in pulmonary fibrosis

PROARYTHMIC - while it treats dysrhythmias, it may also provoke them

enhanced anticoagulant effect with anticoagulants (bleeding)

proarrhythmic effect with other antidysrhythmic agents (cardiac arrest).

Always want to check pulse and BP before administering drugs

Watch coagulant effects

Antidysrhythmics: Assessment

With lidocaine (Xylocaine), important to assess what systems?

CV (with attention to HR and BP) and CNS

Respiratory, thyroid, hepatic and/or hypertensive conditions

Antidysrhythmics given IV should always be on an infusion pump.  

Amiodarone (Cordarone) may cause GI upset (commonly occurs during admin of loading dose).

Confusion and convulsions

Antidysrhythmics: Evaluation

What should you assess with Class III drugs?

No caffeine – increase HR

Take with food – potential GI upset

Take antacids 2 hrs before or after – interfere with absorption

Photosensitivity – watch sunlight exposure