Pharmacokinetics, Pharmacodynamics, and Pharmacogenetics - Key Terms

Vocabulary flashcards covering core terms and concepts from pharmacokinetics, pharmacodynamics, pharmacogenetics, and related labs.

Pharmacokinetics

The movement of drugs through the body: absorption, distribution, metabolism (biotransformation), and excretion.

Absorption

Drug movement from the GI tract into the bloodstream.

Disintegration

Breakdown of an oral dosage form into smaller particles.

Dissolution

Process of drug particles dissolving in liquid to form a solution.

First-pass effect

Liver metabolism of a drug after oral administration, reducing the amount reaching systemic circulation.

Bioavailability

Percentage of the administered dose that reaches systemic circulation.

Portal vein

Blood vessel that transports drugs from the GI tract to the liver for metabolism.

Distribution

How a drug spreads through the body's compartments after absorption.

Protein binding

Attachment of a drug to plasma proteins (e.g., albumin); affects free drug levels and distribution.

Albumin

Major blood protein that binds many drugs, influencing distribution and free drug availability.

Volume of distribution (Vd)

Theoretical volume that would be required to contain the total amount of drug in the body at the same concentration as plasma.

Blood-brain barrier

Protective barrier that limits drug entry into the CNS; only certain drugs cross readily.

Placental transfer

Movement of drugs across the placenta to the fetus.

Metabolism / Biotransformation

Liver-driven chemical alteration of drugs to more water-soluble forms for elimination.

Half-life

Time required for drug concentration to fall by half in the body.

Loading dose

Initial large dose given to rapidly achieve minimum effective concentration.

Excretion

Elimination of drugs from the body, mainly by the kidneys; can also occur via bile, lungs, etc.

Creatinine

Waste product used to assess kidney function; elevated levels indicate dysfunction.

BUN (Blood Urea Nitrogen)

Blood test indicator of kidney function; elevated in renal impairment.

Glomerular filtration rate (GFR)

Rate at which the kidneys filter plasma; a key measure of renal function.

Therapeutic drug monitoring (TDM)

Measuring drug levels to maintain concentrations within a defined therapeutic range.

Peak level

Highest drug concentration in plasma, indicating absorption rate and potential toxicity risk.

Trough level

Lowest drug concentration before next dose, indicating rate of elimination.

Therapeutic index

Range between minimum effective concentration and toxic concentration for a drug.

Onset

Time it takes for a drug to reach minimum effective concentration.

Peak (in pharmacodynamics)

Time of highest drug concentration and often maximal effect or risk of side effects.

Duration

Length of time a drug exerts its therapeutic effect.

Receptor theory

Drugs bind to receptors to activate or inhibit a response.

Agonist

Drug that activates a receptor to produce a biological response.

Antagonist

Drug that blocks or reduces a receptor's response.

Side effects

Secondary, predictable drug effects not part of the intended therapeutic effect.

Adverse drug reactions

Unwanted, harmful reactions to a drug, ranging in severity from mild to life-threatening.