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Norpace CR
By affecting certain electrical signals in the heart, Norpace CR can help control certain types of irregular heart rhythms. This controlled-release capsule slowly releases the medication. It is taken twice daily, with 12 hours between doses. Some people taking this drug may experience side effects like constipation, dry mouth, or difficulty urinating.
Norpace® CR (disopyramide) is a prescription medication used to treat a certain type of serious abnormal heartbeat, or heart arrhythmia. It is specifically approved to treat life-threatening, irregular heartbeats that begin in the lower chambers of the heart, known medically as ventricular arrhythmias. It belongs to a group of drugs called antiarrhythmics.
Norpace CR is a controlled-release capsule that is specially designed to slowly release the medication into the body. There is also an immediate-release version available. Controlled-release Norpace is taken fewer times a day than immediate-release Norpace.
(Click Norpace CR Uses for more information on this topic, including possible off-label uses.)
Norpace CR is made by G.D. Searle, LLC, a division of Pfizer, Inc.
Norpace CR belongs to a group of medications known as Class I antiarrhythmics; specifically, it is a Class IA antiarrhythmic. Class I antiarrhythmic medications block sodium channels in the heart. This slows down the speed at which electrical impulses move through the heart, which helps stabilize the heart rhythm.
Norpace CR also prolongs the heart's refractory period, which is the period of time heart cells will not respond to a new electrical signal. By extending the refractory period, Norpace CR helps the heart tissue resist any electrical signal that is trying to come through prematurely.
Written by/reviewed by: Susan Lakey, PharmD, MPH, BCPP
Last reviewed by: Kristi Monson, PharmD