Re: Coreg

Posted By CCF CARDIO MD - DLB on April 29, 1998 at 08:53:35:

In Reply to: Coreg posted by Jan on April 28, 1998 at 23:40:17:






Hello!  I have dilated cardiomyopathy and have been taking Coreg for the past ten months and have experienced significant improvement in EF (from 15% to 48%) and heart size (reduced 2 cm), however, I still experience significant weakness, fatigue, shortness of breath, etc.  I have a few questions about this medication that I haven't been able to get answers to.  What is the half life of Coreg?  Does a person build up a tolerance to this medication?  Do people usually maintain the gains over time that they initially experience with Coreg?  Does symptom relief usually lag behind the changes in heart functioning (my heart functioning is improving but I am not feeling a whole lot better).  I appreciate any information you can give me.  Thank you, Jan      
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Dear Jan:
The duration of action of Coreg is over 15 hours.  There is no development of tolerance to this type of drug.  I would expect the gains produced by this drug to continue, unless your underlying heart condition worsens.  There is no reason to think that the beneficial effect of Coreg decreases over time, but the medicine has not been widely used for a long enough period of time to be absolutely certain.  
The ejection fraction (EF) is a rough guide to how well the heart is pumping blood.  The actual number does not always tightly correspond to the symptoms that an individual patient feels.  Some people have an EF of 10% and have no symptoms at all.  Other people have an EF of 25% and are completely debilitated.  The individual response to a low EF depends in part on how well your peripheral muscles have compensated to your degree of heart failure.  Ideally, the muscles learn to adapt to a more sluggish level of blood supply and oxygen delivery.  This is why a supervised cardiac rehabilitation program is so important for people with dilated cardiomyopathy.  Also, remember, when talking about EF, normal is 65-70%.
I certainly hope your symptoms improve with time.  Meanwhile, you should discuss with your doctor the possibility of entering a cardiac rehabilitation program.  Good luck.
If you wish to be evaluated here at the Cleveland Clinic, please call 1-800-CCF-CARE for an appointment with a heart failure cardiologist at desk F25.  Information provided in the Heart Forum is for general purposes only.  Specific diagnoses and therapies can only be provided by your doctor.