(AD)ME Flashcards
(44 cards)
ADME
Absorption, Distribution, Metabolism, Excretion
Pharmacokinetic (PK) Phase
Dose, dosage form, frequency, and route of administration as related to drug level vs time.
Pharmacodynamic (PD) Phase
The concentration of a drug at the site of action as related to efficacy.
How are the Metabolism and Excretion phase combined into one term?
Elimination
Route of Administration
The pathway that the drug enters the body with respect to sites of absorption
Distribution
The partitioning of the drug through various organs and site in the body.
Volume of Distribution
The APPARENT volume into which the drug is distributed which is determined by amount of drug administered, divided by initial drug concentration. For example, a very small pill with a small concentration detectable in the blood would be expected to have been diluted by a VERY large volume. Hence it would have a large volume of distribution.
Drug Metabolism
The process in which a drug is biochemically modified through a series of reactions (often enzymatic).
What are the ideal features of a drug in the context of ADME?
Transported by body fluids, tranverses biological membranes, does not readily dilute and distribute through the entire body, reaches relevant sites of actions, and correctly acts on its target.
Advantages and disadvantages of Route: Oral
Noninvasive and good for repeated administration, but has heavy first pass effect and requires patient compliance
Advantages and disadvantages of Route: Sublingual
Rapid entry without first pass effect, but limited by taste
Advantages and disadvantages of Route: Rectal
Avoids undesirable oral complications and less first pass effect but is invasive
Advantages and disadvantages of Route: Parenteral
100% absorption, rapid onset, but requires physician administration
Bioavailability
The concentration at which a specific drug is available for reaction at a given time
Paracellular Pathway
Drug entry into an organ by traveling through the tight junctions between cells
Trancellular Pathway
Travelling through a cell via Endocytosis, active transport, passive transport, facilitated diffusion
What molecules can pass a cell membrane?
Small hydrophobic molecules like oxygen and small uncharged polar molecules like water (but note that most cells also use channels for them too, like aquaporins)
Endocytosis
The cell membrane encompasses a material to allow it into the cell
Fick’s Law of Diffusion
The rate of transport in a membrane is a product of surface area, the diffusion coefficient of a material and the relative concentration of the material reaching equilibrium. That product is then divided by thickness of said membrane.
Facilitated Diffusion
Allowance of chemicals to passively travel through a designated channel
Active Transport
Using energy to transport a material against its concentration gradient.
Solute Carrier (SLC)
Used to transport medium sized molecules in passive transport
ATP Binding Cassette
Uses ATP to actively transport chemicals.
Uniport
Passive transport through one channel in one direction with one molecule
