Taiwan Pharmacist Licensing Examination key terms

The fraction of an administered dose of a drug that reaches systemic circulation unchanged, expressed as a percentage or decimal; intravenous dosing is defined as 100% bioavailable.

Presystemic metabolism of an orally absorbed drug by intestinal wall or liver before it reaches systemic circulation, which lowers oral bioavailability and may require a larger oral dose.

The integral of plasma drug concentration versus time, reflecting total systemic exposure after a dose; used to calculate bioavailability, clearance, and bioequivalence comparisons.

The volume of plasma from which a drug is completely removed per unit time, reflecting the body's efficiency at eliminating the drug; total clearance equals the sum of renal, hepatic, and other clearances.

The apparent volume relating the amount of drug in the body to its plasma concentration; a large value indicates extensive tissue distribution rather than confinement to plasma.

The time required for plasma drug concentration to fall by half during first-order elimination; determines dosing interval and time to reach steady state (about four to five half-lives).

The condition in which drug input rate equals elimination rate, so plasma concentrations fluctuate within a constant range; reached after roughly four to five elimination half-lives of regular dosing.

An initial larger dose given to rapidly achieve a target therapeutic plasma concentration, calculated from volume of distribution and desired concentration rather than from clearance.

A pharmacologically inactive derivative that must undergo chemical or enzymatic conversion in the body to release the active drug, often used to improve absorption, stability, or targeting.

A chemical group that replaces another group in a molecule while retaining similar steric and electronic properties, preserving biological activity but potentially improving potency, stability, or pharmacokinetics.

The systematic study of how changes to a molecule's chemical structure affect its biological activity, used to guide rational drug design and optimization of lead compounds.

A prototype molecule that shows a desired biological activity and serves as the starting point for structural modification and optimization during drug discovery.

The geometric property of a molecule that is non-superimposable on its mirror image, usually due to a carbon bearing four different substituents; enantiomers can differ markedly in pharmacological activity.

One of a pair of stereoisomers that are mirror images of each other and rotate plane-polarized light in opposite directions; they may have different potency, toxicity, or pharmacokinetics.

An equimolar mixture of two enantiomers that is optically inactive overall; regulatory and therapeutic decisions often favor a single pure enantiomer when activities differ.

A naturally occurring basic nitrogen-containing compound found mainly in plants, often pharmacologically active (for example morphine or atropine) and typically extracted after basification into organic solvent.

A natural product in which a sugar moiety is linked to a non-sugar aglycone through a glycosidic bond; hydrolysis yields the aglycone and sugar, and the sugar affects solubility and activity.

The non-sugar portion of a glycoside that remains after hydrolysis of the glycosidic linkage and usually carries the principal pharmacological activity of the glycoside.

A chemically characteristic constituent used to identify a crude drug or to standardize and quantify an herbal preparation, even when it is not the sole active component.

A ligand that binds a receptor and activates it to produce a biological response; full agonists produce maximal response while partial agonists produce a submaximal response even at full occupancy.

A ligand that binds a receptor without activating it and blocks the effect of agonists; competitive antagonists are surmountable by increasing agonist concentration, whereas noncompetitive antagonists are not.

An agonist that binds and activates a receptor but cannot produce the maximal response of a full agonist, even at saturating concentrations; it can act as a functional antagonist when a full agonist is present.

A ratio of the dose producing toxicity to the dose producing the desired effect (often TD50/ED50); a small value indicates a narrow margin of safety requiring careful monitoring.

A graph plotting the magnitude of a pharmacological response against drug dose or concentration, from which potency (ED50) and maximal efficacy (Emax) are derived.

Measurement of plasma drug concentrations to individualize dosing for drugs with narrow therapeutic indices or unpredictable pharmacokinetics, such as digoxin, lithium, and vancomycin.

A separation technique in which a liquid mobile phase is pumped through a packed column under pressure, resolving mixture components for identification and quantitative assay, commonly with UV detection.

A plot of detector response versus known analyte concentration used to quantify unknown samples; its linear range, slope, and correlation coefficient establish the method's working range.

A known amount of a compound added to all samples and standards in an analytical method to correct for variation in injection volume, sample preparation, and instrument response.

The set of regulatory requirements ensuring that medicinal products are consistently produced and controlled according to quality standards covering premises, personnel, documentation, and validation.

An official compendium of drug standards, monographs, and analytical methods that legally defines the quality, purity, and strength of medicines within a jurisdiction.

The set of testing and sampling procedures performed on raw materials and finished products to verify compliance with specifications such as identity, assay, purity, and dissolution.

The demonstration that two pharmaceutically equivalent products have comparable rate and extent of absorption, typically judged by 90% confidence intervals of AUC and Cmax falling within 80-125%.

Any preventable deviation during prescribing, transcribing, dispensing, or administration of a medicine that may cause harm; includes wrong drug, dose, route, or patient.

A structured process of comparing a patient's current medication list with newly prescribed medicines at transitions of care to identify and resolve discrepancies and prevent errors.

A harmful and unintended response to a medicine occurring at doses normally used for prophylaxis, diagnosis, or treatment, excluding therapeutic failure and overdose.

A dosage form engineered to release drug slowly over an extended period, reducing dosing frequency and smoothing plasma concentration fluctuations compared with immediate-release products.

An inactive ingredient added to a dosage form to serve functions such as diluent, binder, disintegrant, lubricant, or preservative, affecting manufacturability, stability, and drug release.

A medicine subject to special legal restrictions because of abuse or dependence potential, requiring secure storage, prescription limits, and record-keeping under narcotics regulations.