Norpace

Hello,

What is your opinion of norpace vs. amiodarone? I've read of some nasty long term side effects of amiodarone. Are there any long term side effects of norpace? When should norpace be prescribed? Are there any conditions that preclude prescribing norpace? Does one need to hospitalized for observation when first going on norpace?

Many thanks!

[CCF-M.D.-RCJ]

Rossi,

Thanks for the post.

Q:"What is your opinion of norpace vs. amiodarone?"

Not to be glib, but this is somewhat like asking someone what is their opinion of red versus white wines.  These two drugs can be used in entirely different circumstances.  There are some people with disease A that I would almost never give amiodarone, but would then give them amiodarone if they developed disease B.  Similarly for disopyramide (norpace).

Q:"Are there any long term side effects of norpace?"

Amiodarone accumulates in body tissues, which is the source for many of the long-term complications with this drug.  Disopyramide does not accumulate in tissues, but is associated with several side effects/complications that are not dependent on tissue accumulation.  Some of these complications can include (common and frequent) dry mouth, constipation, (less common but more dangerous) slowing of the heart rate, dangerous arrhythmias, and worsened heart failure.

Q:"When should norpace be prescribed?"

There are not set indications for prescribing anti-arrhythmic drugs (AADs) like there are for anti-biotics.  Use of AADs is not protocol driven, and really depends on a physician's skill and experience with these drugs.  However, disopyramide is most commonly prescribed to patients with afib who otherwise have normal hearts.  Some physicians particularly use this drug for persons whom they think have vagally-mediated afib.  This is the indication for which I sometimes prescribe the drug.

Q:"Are there any conditions that preclude prescribing norpace?"

Bradycardia, heart failure, renal failure, hepatic dysfunction, intolerance to class Ia AADs, and long QT syndrome would be three reasons not to use this drug.  Others reasons exist as well.

Q:"Does one need to hospitalized for observation when first going on norpace?"

Depends on who is the "one".  Some people could be started without hospitalization, but others would need 48 hours observation.

Hope that helps.