Basic Principles of Pharm/Pharmacokinetics/Pharmacodynamics

Question 1

adverse Drug Reactions

Answer 1

any harmful & unintended response to drug
occurs at normal prophylaxis treatment
side fx, allergies, drug interactions

Question 2

Pharmacokinetics

Answer 2

Action of BODY on med (what body does to med)
ADME process (absorption,distribution,metabolism,elimination)

Question 3

Pharmacokinetics are used for:

Answer 3

design optimally beneficial drug therapy regimes

proper drug, route of administration, dosing schedule

Question 4

Absorption

Answer 4

movement of drug from site of admin to central compartment

occurs via passive/active transport

Question 5

Distribution phase 1

Answer 5

drug transported to site, reacts with tissue+receptors
distributes into interstitial fluid/intracellular fluid
rate of delivery depends on C.O, blood flow, capilalry permeability, tissue volume
well profused organ receive most drug initially (brain, liver, kidney)

Question 6

Distribution Phase 2

Answer 6

delivery to muscle/viscera/skin/fat
slower (involves more body mass)
drug binding to plasma proteins & macromolecules of tissues limit concentration of free drug

Question 7

Metabolism

Answer 7

convert active lipid soluble compounds to water-soluble substances that be excreted

Question 8

Metabolism phase 1

Answer 8

hepatic enzyme (cpy 450)oxidize, demethylate, hydrolyze drugs
cyp450 sensitive to induction/inhibition=DI

drugs w/short 1/2 life metabolize completly during 1st pass. less likely to have DI if metabolized completly

Question 9

Metabolism Phase 2

Answer 9

large water soluble substances are attached to drug

compounds can circulate through 1-2 phases before water-soluble characteristics is present

Question 10

Hepatic Microsomal Enzyme

Answer 10

phase 1 mixed function oxidase
More commonly induced/inhibited by drugs
(inhibiting=more active state=more outcome)

Question 11

CYP450 System

Answer 11

responsible for oxidyzing many drugs

families CYP1, CYP2, CYP3, CYP4, primarily involved w/drug metabolism

Question 12

Enzyme Inhibition

Answer 12

decrease rate of metabolism by obstructing metabolizing enzymes
leads to increase of drug concentration, increased 1/2life, accumulation, side effect/toxicity

Question 13

Enzyme Induction

Answer 13

stimulates increase in CYP450 enzyme activity

increase clearance of drug, decrease drug concentration

Question 14

Elimination/Excretion

Answer 14

removes drugs&metabolites
primarily through urine (also feces and lungs)
drugs are eliminated unchanged or converted to metabolites
lipid-soluble drugs not as readily converted to metabolites

Question 15

Factors affecting pharmacokinetic principles

Answer 15

age/sex/wright/disease state/genetic factors

Question 16

Pharmacdynamics

Answer 16

action of DRUG on body
biochemical+physiological effects of drugs and mechanisms of action
common mechanism for drug interactions

Question 17

Types of Pharmacodynamics

Answer 17

synergism/antagonism/altered cellular transport/effects on receptor sites

Question 18

Most Important Parameters Governing Drug Distribution

Answer 18

bioavailability/volume of distribution/clearance/elimination

Question 19

Bioavailability (F)

Answer 19

fractional extent to which dose of drug reaches site of action
rout of drug administration should be based on understanding of what decreases F

Question 20

Factors tha Decrease F

Answer 20

GI absorption/first pass effect/metabolism

Question 21

Volume of Distribution

Answer 21

relates amount of drug in body to the concentration of drug in blood or plasma depending on fluid measured

volume that would be required to contain all drug in body at same concentration

Question 22

Half Life

Answer 22

time it takes for plasma concentration to be reduced by 1/2

takes roughly 7 1/2 lives to get to point of steady concentraton

Question 23

Steady State

Answer 23

rate in=rate out
takes approx. 5 1/2 lives to reach steadfy state

Amnt if drug administered in a period (maintenance dose)=amnt eliminated in same period

Question 24

Drug Interaction

Answer 24

desired or undesired pharmacology results
effect of one drug (object drug) is changed by another drug (precipitate drug)
drug-drug, food-drug, drug-disease

Question 25

Pharmacokinetic Drug Interaction

Answer 25

Occurs when ADME of 1 drug is affected by another drug/agent

Question 26

Interactions with Absorption

Answer 26

GI-physiological problems w/GI can chane absorption
PH (taking something w/milk can cause oit to chelate/become innert)
increase&decrease motility can cause it to move through faster, change amounts of meds in system
changes in GI flora

Question 27

Interactions with Distribution

Answer 27

plasma protein-if drug binds to protein youre not getting as much action
bond VS unbound: 1 med may be bound, then another drug kicks it off and it will bind mow other drug is free

Question 28

Interactions with Metabolism

Answer 28

hepatic liver enzymes (cytochrome P-450, CYP 3A4)

inducers; induce hepatic liver enzymes (vigarette smoking, phenytoin)

inhibitors; inhibit hepatic liver enzymes (grapefruit, tagamet)

Question 29

Interactions with Elemination

Answer 29

urinary ph-change in ph can effect weather or not drugs are exchanged or excreted
competition-some meds comete for elimination, so some meds will stay in body longer and get more of an effect from penecillin

Question 30

Pharmacodynamic Drug Interactions

Answer 30

additive effects (synergistic)
opposing effects (antagonistic)

Question 31

Potentiation/Synergism

Answer 31

Interacton between 2 or more drugs resulting in pharmacological response greater than the sum of individual response to each

Question 32

Antagonism

Answer 32

opposite in action/smaller than combines effect than with individual agents
get less than you expect from either one

Question 33

During absorption, where is there high probability of DI to occur

Answer 33

the GI tract