Which abbreviation indicates medication is to be taken by mouth?

The abbreviation "PO" stands for "per os," which is a Latin term meaning "by mouth." This is a common instruction in medication administration that indicates the patient should take the medication orally. When medications are prescribed to be taken this way, it signifies that the substance should be ingested and absorbed through the digestive tract, which is the most common route of administration for many drugs.

The other abbreviations do not refer to oral medication administration. For instance, "pr" refers to "per rectum," indicating that a medication is to be administered rectally. "OU" stands for "oculus uterque," which means "both eyes," and is used when medication is intended for use in both eyes. Similarly, "AU" means "auris utraque," referring to both ears. Understanding these distinctions is critical for correct medication administration and ensuring patient safety.