What is the correct order from fastest to slowest absorption sites for injections?

What is the correct order from fastest to slowest absorption sites for injections?

• A. Intravenous, Intramuscular, Subcutaneous
• B. Intradermal, Intramuscular, Subcutaneous
• C. Intramuscular, Subcutaneous, Intradermal
• D. Subcutaneous, Intradermal, Intramuscular

Answer: (C)

Absorption rate depends on how well the tissue is supplied with blood. Muscle has the richest blood supply, so injections given into muscle are absorbed into the bloodstream fastest. Subcutaneous tissue has less blood flow, so absorption is slower. Intradermal injections go into the dermis, which has limited surface area and slower systemic uptake, making absorption the slowest of the three. So the fastest to slowest order is intramuscular, then subcutaneous, then intradermal. (If an intravenous route were included, it would be faster than any tissue injection since it goes directly into the blood.)

Absorption rate depends on how well the tissue is supplied with blood. Muscle has the richest blood supply, so injections given into muscle are absorbed into the bloodstream fastest. Subcutaneous tissue has less blood flow, so absorption is slower. Intradermal injections go into the dermis, which has limited surface area and slower systemic uptake, making absorption the slowest of the three. So the fastest to slowest order is intramuscular, then subcutaneous, then intradermal. (If an intravenous route were included, it would be faster than any tissue injection since it goes directly into the blood.)