Which route delivers medication into the bloodstream?

• A. Intramuscular
• B. Intravenous
• C. Subcutaneous
• D. Rectal

Answer: (B)

Delivering a drug into the bloodstream means it goes into the blood quickly and directly, without having to pass through tissues first. The intravenous route places the medicine straight into a vein, so it enters the bloodstream immediately and the effects begin rapidly.

In contrast, intramuscular and subcutaneous routes deposit the drug into muscle or fatty tissue, and it must be absorbed into the bloodstream through capillaries, leading to a slower onset of action. The rectal route can still reach the bloodstream, but its absorption is variable and not as direct or predictable as intravenous administration. Therefore, the route that delivers medication into the bloodstream most directly is the intravenous route.