Yes, there are some medicines you may want to avoid if you are taking carvedilol. With other medicines, your doctor may keep a close watch on you. Some of these medicines are:

CYP2D6 enzyme inhibitors.  These medicines may raise the level of carvedilol in your blood. This may make you feel dizzy. Most people are usually fine taking them together. But let your doctor know at once if you feel new symptoms. Some CYP2D6 inhibitors are fluoxetine, paroxetine, propafenone, and quinidine.

Rifampin. Taking rifampin with carvedilol can decrease carvedilol levels significantly. This can make your carvedilol medicine less useful. Rifampin is also called rifampicin or the brand name Rifadin.

Blood pressure-lowering medicines. Taking carvedilol with these can lower your blood pressure or heart rate by too much. You should closely watch your blood pressure and heart rate if they are taken together. Some blood pressure-lowering medicines are reserpine, monoamine oxidase inhibitors, and clonidine.

Cyclosporine. Taking carvedilol with cyclosporine can increase your cyclosporine levels. Your doctor may have you lower your cyclosporine dose a little bit. Brand names of cyclosporine are Neoral, Sandimmune, Restasis, and Gengraf.

Digitalis glycosides. Taking carvedilol with digitalis glycosides raises your digoxin levels. This can raise the risk of your heart rate becoming too slow. 

Amiodarone. Taking amiodarone while on carvedilol may increase carvedilol levels. This can cause your heart rate to become too slow. Brand names for amiodarone are Nexterone, Cordarone, and Pacerone.

Calcium channel blockers (CCBs). Taking carvedilol with certain CCBs may slow your heart rate down. It may also drop your blood pressure too much or disturb your heart rhythm. The types of CCBs that may have this effect are verapamil and diltiazem.

Insulin or oral blood sugar-lowering medicines. Using insulin and carvedilol together can lower your blood sugar levels too much. It can also hide low blood sugar symptoms. Make sure to closely watch your blood sugar levels.

This list does not include all the medicines that should be used with caution when taken with carvedilol. So, talk to your doctor or pharmacist about all the medicines you take.

Keep yourself safe – tell your doctor what you take!