PK Foundations
This branch of pharmacology describes what the body does to the drug over time.
What is pharmacokinetics?
This is the most common but most variable route of drug administration.
What is oral administration?
This is the primary mechanism by which most drugs cross biological membranes.
What is passive diffusion?
This transport mechanism moves drugs down a concentration gradient without energy.
What is facilitated diffusion?
This is the primary site of drug absorption in the GI tract.
What is the small intestine?
This term describes the fraction of an administered dose that reaches systemic circulation unchanged.
What is bioavailability?
This route bypasses first-pass metabolism and is commonly used for nitroglycerin.
what is sublingual (or buccal) administration?
Only this form of a weak acid or base readily crosses lipid membranes.
What is the unionized form?
This transport process requires ATP and can move drugs against a concentration gradient.
What is active transport?
Large surface area, villi, and high blood flow make this site ideal for absorption.
What is the small intestine?
These four processes make up pharmacokinetics.
What are absorption, distribution, metabolism, and excretion (ADME)?
This parenteral route provides the greatest control over plasma drug concentration.
What is intravenous administration?
This equation relates pH, pKa, and the ratio of ionized to unionized drug.
What is the Henderson–Hasselbalch equation?
This type of transport can become saturated and is highly selective.
What is carrier-mediated transport?
This physiological process strongly influences oral drug absorption time.
What is gastric emptying?
This pharmacokinetic parameter is 100% for IV administration.
What is bioavailability?
Absorption via this route depends heavily on blood flow to the injection site.
What is subcutaneous administration?
A weak acid placed in plasma at pH 7.4 will mostly exist in this form.
What is the ionized form?
Vitamin B12 absorption with intrinsic factor is an example of this transport.
What is vesicular transport (endocytosis)?
Food generally causes oral drug absorption to be faster or slower?
What is slower?
This concept links drug concentration over time to drug effect.
What is the relationship between pharmacokinetics and pharmacodynamics?
This route is ideal for lipid-soluble drugs requiring rapid local or systemic effects.
What is inhalation?
This phenomenon explains why salicylic acid becomes stuck in plasma.
What is ion trapping?
This transport mechanism allows highly ionized drugs to be absorbed by pairing with oppositely charged ions.
What is ion-pair transport?
This term describes the time a drug spends in the GI tract available for absorption.
What is the absorption window (or residence time)?