Do not take the drug if it causes an allergic reaction. Special warnings about this medication Return to top Coreg sometimes aggravates chronic bronchitis and emphysema. If you have either condition, make sure the doctor is aware of it. You'll need to use the drug cautiously. Report any weight gain or shortness of breath to your doctor immediately.
Liver damage is a rare side effect of the drug.
You will need to be switched from Coreg. Make sure your doctor knows if you have diabetes or low blood sugar. Coreg can interfere with the effectiveness of diabetes drugs and can cover up the symptoms of low blood sugar. Monitor your blood sugar regularly, and report any changes to your doctor. When Coreg is taken for heart failure, there is a slight chance that it will interfere with the kidneys.