Which route is used for injecting into the muscle and is usually absorbed quickly?

• A. Intramuscular injection
• B. Intravenous injection
• C. Sublingual
• D. Inhalation

Answer: (A)

Placing the drug into muscle tissue is the intramuscular route, and it’s absorbed quickly because muscle has a rich blood supply that carries the medication into the bloodstream fairly rapidly. This makes the onset faster than injections into subcutaneous tissue, though not as immediate as delivering the drug directly into a vein. The exact speed can depend on factors like the site (deltoid tends to absorb fairly quickly due to good perfusion), the volume injected, and whether the preparation is aqueous or oil-based (aqueous solutions generally enter circulation faster). In practice, intramuscular injections are used when IV access isn’t available or when a rapid but not immediate effect is acceptable. By contrast, sublingual methods skip injection entirely and absorb through the mouth’s mucosa, inhalation delivers medication via the lungs, and intravenous delivery goes straight into the bloodstream for the fastest possible onset.