Which forms of administration are classified as parenteral?

Parenteral administration refers to methods of delivering medication that bypass the gastrointestinal tract, typically through injections or other non-oral means. Intravenous (IV) administration delivers medication directly into the bloodstream, allowing for immediate effects. Intramuscular (IM) injections deposit medication deep into muscle tissue for more prolonged absorption, while subcutaneous (SC) injections place medication into the fatty tissue beneath the skin, offering slower absorption than IM injections. Intradermal injections are used for local effects or allergy testing, delivering medication directly into the dermis layer of the skin.

The answer includes topical/transdermal and inhalation methods. Although topical and transdermal routes are not typically classified as parenteral since they don’t involve injections, inhalation is another valid route that bypasses the GI tract and permits rapid absorption through the lungs.

In contrast, options that include oral or rectal administration do not fit the definition of parenteral routes, since they involve the digestive system. Therefore, the correct answer clearly identifies the proper parenteral routes of administration.