Which phrase best defines intravenous administration?

• A. Administration into a nerve.
• B. Injection into a muscle.
• C. Administration into a vein.
• D. Administration into an artery.

Answer: (C)

Intravenous administration means putting a substance directly into a vein. This delivers meds right into the bloodstream, causing rapid onset and allowing precise dosing, since the substance bypasses the body’s absorption barriers that other routes must go through. It’s ideal for fluids or irritant drugs and for situations needing quick effect, but it requires careful technique to avoid complications like infection or air bubbles. The other options describe delivering into muscle, nerve, or an artery, which are not intravenous routes. So the phrase that defines intravenous administration is administration into a vein.