"Rapid-acting" refers to substances or medications that take effect quickly after administration. This term is often used in the context of certain types of insulin, such as aspart or lispro, which are designed to lower blood sugar levels shortly after a meal. These medications are crucial for individuals with diabetes who need to manage their blood glucose levels effectively. In addition to insulin, the term can also apply to other medications, such as pain relievers or anxiolytics, that provide fast relief from symptoms. Rapid-acting treatments are beneficial in emergency situations or when immediate results are necessary for patient care.