bioavailability
The proportion of a drug or other substance that enters systemic blood circulation when introduced into the body and so is able to have an active effect.
Intravenous drugs have 100% bioavailability by definition, whereas oral drugs often have lower bioavailability due to incomplete absorption and first-pass liver metabolism.
Word relationships
- systemic absorption: Systemic absorption refers to the process of entering circulation, while bioavailability quantifies the fraction that successfully reaches target circulation intact.
Commonly confused with
- absorption: Absorption is the movement of a drug from its site of administration, whereas bioavailability specifies the exact percentage of unchanged drug reaching systemic circulation.
Word family
- bioavailable (adjective): Capable of being absorbed and utilized by the biological system.
Collocations
- oral bioavailability
- high bioavailability
- enhance bioavailability
- systemic bioavailability
- relative bioavailability
Example sentences
- "Formulating the medication as a nanoparticle emulsion significantly increased its oral bioavailability." Pharmacokinetic Study
- "First-pass metabolism in the liver drastically reduces the bioavailability of many oral cardiac agents." Medical Education
Memory hook
BIO (biological body) + AVAILABLE: How much drug is AVAILABLE to your biological system. Bioavailability = The percentage of drug that makes it to the bloodstream.
When not to use
Do not use 'bioavailability' to describe simple nutritional presence in food unless referring to biological absorption into bloodstream.
Fun facts
- Drinking grapefruit juice can unexpectedly boost the bioavailability of certain medications by blocking intestinal enzymes that normally break them down.
Related words
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