Extended-release medicines slowly release medicine into the body. This reduces how fast the body absorbs the medicine. There may be three benefits to this:
Extended-release medicines are not used when a medicine is first prescribed and the final dose has not been determined. They usually are not used unless side effects are a problem, it is hard to take the nonextended-release form, or you need a long-acting medicine.
Extended-release medicines should never be crushed or chewed. Some of them can be broken in two. Ask your pharmacist about this.
Extended-release medicines also are called modified-release, prolonged-release, controlled-release, controlled-delivery, slow-release, and sustained-release medicines.
Delayed-release medicines are not the same. They release the active ingredients at a certain time after the medicine is taken.
WebMD Medical Reference from Healthwise