Final answer:
A medication injected into a vein, subcutaneous tissue, or muscle is known as parenteral administration, which includes intravenous, intramuscular, and subcutaneous injections. This method is utilized for quick absorption or when the GI tract doesn't adequately absorb the medication.
Step-by-step explanation:
The term for a medication that is injected into a vein, subcutaneous tissue, or muscle tissue is parenteral administration. This route is often utilized when a medication is not adequately absorbed by the gastrointestinal (GI) tract or when a rapid onset is needed. Intravenous injections deliver medication directly into the bloodstream, ensuring quick distribution and often achieving substantially higher plasma levels compared to oral or intramuscular routes. Intramuscular injections involve depositing medication into the muscle where it is absorbed into the bloodstream, while subcutaneous injections are administered into the tissue layer between the skin and muscle, allowing for slower absorption.
Specific examples of medications delivered parenterally include chemotherapy drugs, which are frequently injected intravenously to reach the bloodstream quickly. Vaccines are often administered via intramuscular injections, providing long-term immunity by allowing the immune system to react to the introduced antigens. Other parenteral medications include anesthetics used in surgery and emergency treatments, and hormone-based contraceptives like the Depo-Provera shot.