Which of the following is the route of administration for parenteral medications?

The oral route involves administering medication through the mouth, allowing it to be absorbed in the gastrointestinal tract. This method is not considered parenteral, as it relies on the digestive system for absorption and is subject to first-pass metabolism, which can alter drug effectiveness.

Inhalation is a method of delivering medications directly into the respiratory system, typically for local effects in the lungs. While it is a valid route of administration, it is not classified as parenteral since it does not involve injection into tissues or the bloodstream.

Installation refers to the administration of medication in a specific area of the body, often used for localized treatments (e.g., eye drops). This method does not involve injections and is therefore not considered parenteral.

Transdermal administration involves applying medication through the skin for systemic effects, such as with patches. While it allows for absorption into the bloodstream, it does not meet the definition of parenteral, which specifically refers to injection routes.