Unit 1: Pharmacodynamics

Question 1

Pharmacodynamics

Answer 1

Focuses on the effects of drug on the body

Question 2

Agonists

Answer 2

Bind to and activate the receptor, turns on the response by mimicking an endogenous compound which the pt may be deficient

Question 3

Antagonists

Answer 3

Prevent binding of other molecules; blocks receptor in inactive site

Question 4

Prodrugs

Answer 4

completely reliant on biological processes for activation; genetics may prevent drug from reacting

Question 5

Bioavailabilty

Answer 5

fraction of unchanged drug found in circulation following administration

Question 6

Clearance

Answer 6

Rate of total elimination of drug divided by plasma drug concentration

Question 7

Volume of distribution

Answer 7

measure of the extent to which a drug is distributed in the body

Question 8

Pharmacokinetics

Answer 8

Focuses on the effects of the body on the drug

Question 9

Absorption

Answer 9

Movement of drug from the site of administration into circulation

Question 10

Distribution

Answer 10

Movement of drug from circulation to tissue, including receptor or active site

Question 11

Metabolism

Answer 11

Biotransformation of drugs into metabolites

Question 12

Excretion

Answer 12

Removal of unchanged drug and/or metabolites from the body

Question 13

7 types of transport

Answer 13

Bulk flow, filtration, passive diffusion, facilitated diffusion, active transport, endocytosis, ion pair transport

Question 14

6 Routes of administration

Answer 14

Enteral (epithelial), Inhalation (epithelial), mucous membranes (epithelial), parenteral (endothelial), transdermal, topical (epithelial)

Question 15

Epithelial absorption

Answer 15

Drugs must pass through the cells in the membrane, not between, so absorption is limited by the rates drugs can cross membrane

Question 16

First pass metabolism

Answer 16

term used for hepatic metabolism of a drug when it is absorbed from the stomach and delivered to the liver via portal circulation; Greater first-pass effect, less agent will reach systemic circulation

Question 17

Activated charcoal

Answer 17

Binds everything in the stomach and passes through

Question 18

Therapeutic window

Answer 18

Duration of action and concentration are in harmony; just enough drug to provide best reaction

Question 19

Highly/poorly perfused tissues

Answer 19

H: Brain, kidney, lungs, liver, heart P: Fat, distal extremities

Question 20

Volume of Distribution

Answer 20

A value given to a drug to indicate how well the drug is dispersed through the system; proportional to total drug in system/plasma concentration

Question 21

Influences of drug distribution

Answer 21

capillary permeability, lipid solubility, perfusion and protein binding

Question 22

Metabolism

Answer 22

Alters pharmacological activity of drug and increases ability of body to excrete drugs

Question 23

Phase 1 of metabolism

Answer 23

chemical modification; oxidation/reduction, hydrolysis etc

Question 24

Phase 2 of metabolism

Answer 24

Conjugation/ synthesis; enzymes serve to add large moieties that ionizes he molecule and drastically increases hydrophilicity… increases excretion

Question 25

Cytochrome P450

Answer 25

detoxification and bioactivation; oxidative reactions; primarily occurs in liver; over 60 enzymes

Question 26

Substrate

Answer 26

drug is subject to metabolism by enzyme

Question 27

Inducers

Answer 27

drug induces enzyme activity

Question 28

Inhibitors

Answer 28

drug inhibits enzyme activity

Question 29

Conjugation

Answer 29

adding a molecule to the drug to increase water solubility and increase subsequent excretion; usually decreases biological activity

Question 30

Factors that may effect metabolism

Answer 30

Smoking, age, sex, pregnancy, starvation, infection, circadian rhythm, CV, GI, renal or liver function, career, environment, drugs, alcohol, diet

Question 31

Routes of excretion

Answer 31

Renal (90%), liver, intestines, lung, sweat, saliva, breast milk

Question 32

3 major mechanisms of excretion

Answer 32

Glomerular filtration, tubular secretion, passive reabsorption

Question 33

Glomerular filtration

Answer 33

Occurs in Bowman's capsule, dominated by bulk flow filtration, rate is driven by hydrostatic pressure, size dependent

Question 34

Tubular secretion

Answer 34

Active transport of large molecules or protein bound molecules FROM plasma TO urine across epithelial cells; can move molecules across concentration gradient; can be saturated or inhibited

Question 35

Reabsorption

Answer 35

Molecules moving FROM urine To plasma, mediated by diffusion; small, neutral and lipophilic molecules are reabsorbed

Question 36

Biliary drug excretion

Answer 36

hepatocytes actively secrete bile, flows to duodenum and eliminated; several drugs are secreted this way

Question 37

Breast milk excretion

Answer 37

Lipid soluble, non-ionizable molecules freely dissociate in breast milk

Question 38

Zero-order kinetics

Answer 38

Excretion not at all dependent on drug concentration; few drugs behave this way: alcohol; no fixed half life; clearance is constant

Question 39

First-order kinetics

Answer 39

Excretions is HIGHLY dependent on drug concentration; fixed half life; exponential elimination

Question 40

Cockcroft-gault equation

Answer 40

most common equation used to measure creatinine release based on age, sex, weight

Question 41

Child-pugh score

Answer 41

used to adjust meds based on hepatic clearance