Pharmacology glossary
Plain-language definitions of the terms that recur across this reference — the vocabulary prescribing information uses without explaining it.
- Bioavailability
- The proportion of a dose that actually reaches the bloodstream unchanged.
- Clearance
- How quickly the body removes a drug, mainly through the liver and kidneys.
- Contraindication
- A situation in which a medication should not be used at all.
- First-pass metabolism
- Breakdown of a swallowed drug by the liver before it reaches the rest of the body.
- Generic medicine
- A copy of an original medication, containing the same active ingredient.
- Half-life
- The time it takes for the amount of a drug in the blood to fall by half.
- Off-label use
- Prescribing a licensed medication for a use its licence does not cover.
- Pharmacokinetics
- What the body does to a drug — absorption, distribution, metabolism and excretion.
- Steady state
- The point at which the amount going in equals the amount being cleared.