Diltiazem (Dilt Cd, Cardizem) is a calcium channel blocker (CCB) used to treat high blood pressure and angina (chest pain). Diltiazem may also be used for purposes not listed in this medication guide.

You should not use diltiazem if you are allergic to it, or if you have a history of heart attack, stroke, or life-threatening heart rhythm problems.

Do not use diltiazem if you are also taking rifampin, clarithromycin, erythromycin, or telithromycin.

Some medicines can interact with diltiazem and cause a serious condition called serotonin syndrome. Be sure your doctor knows if you are taking any of the following …