What does "intra-arterial" drug administration involve?

Intra-arterial drug administration specifically involves injecting medication directly into an artery. This method is often used to deliver high concentrations of medication directly to a target organ or tissue, which can be particularly advantageous in situations such as localized cancer treatments or when aiming to quickly affect a specific site in the body. The direct access to the arterial circulation allows for rapid distribution throughout the body while minimizing systemic exposure to the rest of the body.

In contrast, the other methods mentioned do not fall under intra-arterial administration. Delivering medication through a vein refers to intravenous administration, which does not involve arteries. Administering drugs via the oral route involves swallowing the medication, allowing it to be absorbed through the gastrointestinal tract, which is entirely different from the arterial route. Applying medication topically refers to using creams or ointments on the skin's surface, which bypasses the circulatory system entirely. Thus, the definition of intra-arterial administration is distinct and specific to the injection of drugs into arteries.