PO meds will never have 100% bioavailability is a true statement.

• A. PO meds will never have 100% bioavailability
• B. IV meds have zero bioavailability
• C. Bioavailability is the amount of drug excreted
• D. Bioavailability is the volume of distribution

Answer: (A)

Bioavailability is the fraction of an administered dose that reaches systemic circulation in active form. For oral medicines, absorption through the GI tract plus first-pass metabolism in the liver often reduce the amount that reaches the bloodstream, so the bioavailability is typically less than 100%. In contrast, medications given by IV are delivered directly into the circulatory system, giving them 100% bioavailability by definition. Therefore the statement about oral meds never reaching 100% bioavailability is generally true.

The other ideas mix up concepts: bioavailability is not the amount of drug excreted—excretion relates to elimination, not entry into circulation. It is also not the volume of distribution, which describes how a drug disperses within the body relative to plasma concentration.