Which of the following routes is considered parenteral administration?

Parenteral administration refers to the delivery of medications by routes other than the digestive tract. This typically involves injections or infusions directly into the body, bypassing the gastrointestinal system. The intravenous (IV) route is a prime example of parenteral administration, as it involves delivering medication directly into the bloodstream using a vein. This method allows for rapid onset of action and is often used in settings where immediate therapeutic effects are necessary, such as in emergency care or for delivering fluids and medications that cannot be given orally.

The other options involve the gastrointestinal tract or mucosal surfaces, which do not fit the definition of parenteral routes. Oral administration involves taking medication by mouth, which requires the drug to pass through the digestive system before entering systemic circulation. Buccal administration, where a drug is placed between the gum and cheek for absorption, also relies on oral mucosa, and rectal administration involves inserting medication into the rectum, a part of the digestive tract. Thus, these routes are not classified as parenteral.