What does 'IM' refer to in medication administration routes?

The term 'IM' in medication administration routes stands for intramuscular. This method involves the injection of medications directly into a muscle. It is commonly used for vaccines, hormones, and certain medications that need to be absorbed quickly or require a larger volume that cannot be administered intravenously or subcutaneously.

Intramuscular injections allow for faster absorption into the bloodstream compared to subcutaneous injections because muscles have a richer blood supply. This route is particularly useful when a more sustained release of medication is desired.

In contrast, the other options refer to different methods of administration: immunization is a process often done through injections but does not specifically define the route; intravenous (IV) refers to medications delivered directly into a vein; and intraosseous involves delivering medications into the bone marrow. Each of these methods has its own applications and implications in medical practice, distinct from the intramuscular route.