General Description
Diltiazem, sold under the trade name Cardizem among others, is a calcium channel blocker used to treat high blood pressure, angina, and certain heart arrhythmias.[1] It may also be used in hyperthyroidism if beta blockers cannot be used.[1] It is taken by mouth or injection into a vein.[1] When given by injections effects typically begin within a few minutes and last a few hours.[1]
Common side effects include swelling, dizziness, headaches, and low blood pressure.[1] Other severe side effects include an overly slow heart beat, heart failure, liver problems, and allergic reactions.[1] Use is not recommended during pregnancy.[1] It is unclear if use when breastfeeding is safe.[2]
Diltiazem works by relaxing the smooth muscle in the walls of arteries, resulting in them opening and allowing blood to flow more easily.[1] Additionally, it acts on the heart to prolong the period until it can beat again.[3] It does this by blocking the entry of calcium into the cells of the heart and blood vessels.[4] It is a class IV antiarrhythmic.