Pharmacology

Question 1

pharmacotherapeutics

Answer 1

the rational clinical use of drugs to prevent, diagnosed, and treat medical conditions

Question 2

three aspects of pharmacotherapy

Answer 2

1) clinical presentation (knowledge about your patient)
2) pathophysiology (knowledge of medical conditions)
3) pharmacology (knowledge of drug action)

Question 3

therapeutics

Answer 3

the whole spectrum of modalities intended to manage medical conditions (e.g. surgery, radiation, chemotherapy)

Question 4

drug

Answer 4

contains a known quantity of an identified pure biologically active substance

Question 5

crude medicinal

Answer 5

an inconsistent mix of different biologically active substances, such as opium

Question 6

nutrients

Answer 6

chemical compounds in food that are used by the body to function properly and maintain health

Question 7

pharmacokinetics

Answer 7

the study of what the body does to a drug

Question 8

pharmacodynamics

Answer 8

the study of what drugs do to the body

Question 9

four stages of pharmacokinetics

Answer 9

absorption

distribution

biotransformation

excretion

Question 10

absorption (drug)

Answer 10

the unidirectional movement of drug from the site of administration to the general blood circulation (the central compartment)

(i.e. the rate and extent that the parent drug reaches the general circulation)

Question 11

two dimensions of absorption and units

Answer 11

rate (how fast); slope of blood concentration (C) over time (t)

extent (how much); area under the C/t curve

Question 12

plasma

Answer 12

the fluid remaining after blood cells are removed from blood

Question 13

parent drug

Answer 13

the chemically unchanged form of the drug

Question 14

bioavailability definition and abbreviation

Answer 14

the fraction of the dose that reaches the general circulation (100% for IV drugs, oral drugs face barriers to absorption)

abbreviated as “F” (for fraction)

Question 15

Bioavailability formula

Answer 15

Bioavailability (F) = (AUC oral/AUC IV)

Determined by measuring blood concentrations at several points after IV injection and measuring concentrations at several points after giving the same dose by any other route

Question 16

Dose

Answer 16

The amount of drug taken at any one time

Question 17

Dosage

Answer 17

The amount of drug taken over a chronological period (per day, per treatment cycle, etc.), and maybe comprised of several doses

Question 18

Distribution

Answer 18

The (reversible) movement of drug between body compartments

Question 19

Volume of distribution

Answer 19

How much blood the dose appears to dissolve in

Volume = drug dose/plasma concentration

Question 20

Biotransformation

Answer 20

The body’s attempt to get rid of the parent molecule and its metabolites (primarily through the liver)

Question 21

Excretion

Answer 21

The rate that the body gets rid of drugs and drug metabolites; may occur via urine, bile, feces, sweat, or breath

Question 22

First-order elimination

Answer 22

The fraction of the drug concentration in plasma decreases by a constant proportion, regardless of the drug concentration (inverse log)

Question 23

Zero-order elimination

Answer 23

The fraction of the drug concentration in plasma decreases by a constant amount determined by the capacity of the elimination pathway (linear slope)

Question 24

Agonist

Answer 24

A drug that binds receptors that are active, and thus increase biological activity

Question 25

Antagonist

Answer 25

A drug that binds receptors that are inactive, blocking an agonist from interacting with the receptor and thus decreases biological activity

Question 26

Partial agonist

Answer 26

A drug that binds active and inactive receptors, increasing biological activity when the receptor equilibrium is mostly inactive, and decreasing biological activity when the receptor equilibrium is mostly active

Question 27

Inverse agonist

Answer 27

A drug that binds to a receptor that is normally always active, but unlike an antagonist that merely blocks an agonist from binding, the receptor, and inverse agonist reverses the receptor activity

Question 28

Drug receptor states

Answer 28

Active and inactive

Question 29

Reversible binding

Answer 29

The drug combined to the receptor and, part over and over again, usually using non-covalent bonds

Question 30

Irreversible binding

Answer 30

The drug covalently binds the receptors and does not dissociate unless the bond is broken by enzyme or other disassociating agents

Question 31

Orthosteric binding site

Answer 31

The drug binds to the usual site where it corresponded ligand usually binds to

Question 32

Allosteric binding site

Answer 32

The drug binds to any sites beside the usual ligand binding site

Question 33

Ligand-gated ion channels

Answer 33

Ionotropic receptors; drugs bind to these channels to alter ion conductance, either leading to hyperpolarization or depolarization (e.g. local anesthetics, sulfonylureas) Happens in milliseconds, e.g. nicotinic ACh receptor

Question 34

G-protein coupled receptors

Answer 34

Metabotropic receptors; The drugs bind to the extracellular domain of a transmembrane receptor which acts on a regulatory GTP binding protein which then generates a second messenger (e.g. beta2 agonist) Happens in seconds, e.g. Muscarinic ACh receptor

Question 35

Kinase-linked receptors

Answer 35

Drugs bind to the extracellular domain of a transmembrane receptor to activate the enzymatic activity of its cytosolic tail (e.g. insulin) Happens in hours, e.g. cytokine receptors

Question 36

Nuclear receptors

Answer 36

Lipid soluble drugs diffuse across the membrane and activate these intracellular receptors [e.g. steroids (estrogen, testosterone), sterols (Vitamin D)] Happens in hours, e.g. ostrogen receptor

Question 37

Competitive

Answer 37

A molecule binds to an enzyme's active site, which prevents the original substrate binding and it's effects can be modulated by changing the substrate concentration

Question 38

Non-competitive

Answer 38

A molecule binds to an enzyme's allosteric site and causes a confirmational change to the enzyme's active site. Increasing the original substrate levels does not reduce the inhibitor's effect

Question 39

One Compartment Model Ratios

Answer 39

Solid:Fluid = Men - 40:60, Women - 45:55 ECF:ICF = (1/3)%:(2/3)% Plasma:Interstitial Fluid = 20%:80%

Question 40

concentration of a drug at the active site is a function of what

Answer 40

concentration of the drug in the blood

Question 41

the most important factor affecting the rate of oral drug absorption

Answer 41

``` stomach emptying (absorption will be minimal until a drug gets past the stomach into the intestine) ```

Question 42

pre-hepatic blood is comprised of what

Answer 42

the splanchnic (portal) circulation that combines with the blood returning to the liver via the hepatic artery

Question 43

the first-pass effect

Answer 43

the extent that the liver prevents a fraction of the dose (when taken orally, rectally, or through skin) from reaching the systemic circulation is called the hepatic first-pass effect

Question 44

hepatic first-pass extraction vs bioavailability

Answer 44

inverse relationship when hepatic first-pass extraction is 100%, bioavailability is 0