Do not take carvedilol if you had an allergic reaction to it in the past. Also, avoid it if you have ever had a very serious allergic reaction to anything. It is likely safe if you have other milder allergies.
Carvedilol may make your severe allergic reactions worse. It may keep your medicines for these allergies from working as well as usual. This may be dangerous for people who need to use epinephrine (e.g. EpiPen).
Tell your doctor about all your allergies before taking carvedilol. Your doctor can help decide if carvedilol is right for you.
Telling your doctor is the key when you have an allergy!