What route of administration is indicated by the abbreviation PO?

The abbreviation PO stands for "per os," which is a Latin term meaning "by mouth." This term is widely used in medical and pharmaceutical contexts to indicate that a medication is to be taken orally. When a drug is administered via this route, it is typically swallowed and absorbed through the digestive tract, allowing for the medication to enter the systemic circulation after processing by the gastrointestinal system.

Oral administration is one of the most common and convenient routes for delivering medications due to ease of use, particularly for patients who can safely swallow tablets or liquids. It is preferred in many situations because it usually involves less invasive procedures and allows for self-administration.

Other routes mentioned, such as rectal, intramuscular, and sublingual, serve specific clinical purposes and have their own abbreviations. Rectal administration involves placement within the rectum, intramuscular refers to injections into muscle tissue, and sublingual means placing the medication under the tongue for rapid absorption. Thus, none of these options represent the oral route indicated by the abbreviation PO.