Which of the following is NOT a route of drug administration?

The correct answer, which identifies a non-route of drug administration, is atmospheric. In pharmacology, routes of drug administration refer to the specific pathways through which a drug is delivered to achieve its therapeutic effect. Common routes include intravenous, subcutaneous, and topical, each with distinct mechanisms for drug absorption and distribution within the body.

Intravenous administration involves the direct introduction of the drug into the bloodstream, allowing for immediate effects and precise control over drug levels. Subcutaneous administration is when a drug is injected into the subcutaneous tissue, enabling gradual absorption. Topical administration applies the drug directly to the skin or mucous membranes, localized to that specific area.

On the other hand, atmospheric does not refer to any recognized method of drug delivery. It does not involve any standard physiological pathways for medication administration, making it the correct choice for this question. Understanding the various legitimate routes of drug administration is essential for pharmacological practice and patient care.