Pharmacokinetics & Pharmacodynamics

Question 1

Pharmacokinetics

Answer 1

The study of the time course of a drugs journey through the body

Absorption, distribution, metabolism, elimination

what the body does to the drug

Question 2

Phamacodynamics

Answer 2

The study of the existing biological effects resulting from the interaction between drugs and biological systems

what the drug does to the body

Question 3

Active drug

Answer 3

Free drug

Drug that is not bound to protein

Question 4

Peds most reliable route of med admin

Answer 4

IV

Question 5

Peds most desirable route of med admin

Answer 5

Enteral

Question 6

Topical med admin in peds

Answer 6

Reduces as skin matures

Question 7

absorption

Answer 7

transfer of drug from the site of administration into circulation

Question 8

bioavailability

Answer 8

amount of drug absorbed into circualtion

Question 9

distribution

Answer 9

partitioning of drug from the circulation into various body fluids, organs, and tissues

Question 10

metabolism

Answer 10

biotransformation of the drug

Question 11

elimination

Answer 11

elimination of the drug from the body

Question 12

primary site of metabolism

Answer 12

the liver

Question 13

primary site of elimination

Answer 13

kidneys

Question 14

potency

Answer 14

amount of drug required to cause effect

Question 15

efficacy

Answer 15

response of the drug (even less efficacious drugs may not have full efficacy)

Question 16

phase I reactions

Answer 16

simple reactions

CYP450

oxidation, reduction, hydrolysis

Question 17

phase II reactions

Answer 17

more complex reactions with molecules added together

conjugation, glucuronidation, sulfation, acetylation, methylation

Question 18

clearance

Answer 18

rate at which drug is eliminated

Question 19

factors that affect GFR

Answer 19

protein binding
renal blood flow
area and nature of glomerular membrane

Question 20

methods of elimination

Answer 20

glomerular filtration, tubular secretion, tubular reabsorption

Question 21

single compartment kinetics

Answer 21

drug is delivered to the central compartment, then eliminated and has action

Question 22

multicompartment kinetics

Answer 22

drug is delivered to central compartment, and rapidly distributed to the peripheral compartment

Question 23

alpha phase

Answer 23

distribution phase of multicompartment kinetics

drug is still being eliminated - blood levels are high

DO NOT DRAW LEVELS DURING THIS PHASE

Question 24

beta phase

Answer 24

phase of gradual elimination - like single compartment kinetics

Question 25

volume of distribution

Answer 25

size of compartment in which drug distributes Vd=dose/concentration

Question 26

half life

Answer 26

time for the drug concentration to decrease by one half generally takes 5 half-lives to eliminate drug from the body

Question 27

first order kinetics

Answer 27

linear or exponential clearance - constant fraction or proportion of drug is removed per unit of time ideal for drug calculations!

Question 28

zero order kinetics

Answer 28

mechanisms for elimination become saturated - more drug is present than system can process, so drug is NOT eliminated at a constant (linear) rate a small increase in dose will result in a large increase in the plasma concentration

Question 29

clearance

Answer 29

rate of elimination / drug concentration single most important factor in determining drug concentrations depends on: dose, organ blood flow, intrinsic function of the liver or kidneys

Question 30

is it ok to draw peaks/troughs off schedule?

Answer 30

okay to get peaks late and troughs early do not obtain peaks early!!! do not get troughs late!!!

Question 31

how to titrate meds based on peaks and troughs?

Answer 31

peaks - adjust dose | troughs - adjust interval

Question 32

sensitivity

Answer 32

concentration required to produce 50% of maximum effect

Question 33

type I reaction

Answer 33

anaphylactic

Question 34

type II reaction

Answer 34

cytolytic ex. hemolytic anemia, ABO mismatch

Question 35

type III reaction

Answer 35

arthrus ex. serum sickness, RA, SLE, cephalosporin rxn

Question 36

type IV reaction

Answer 36

delayed hypersensitivity reaction ex. contact dermatitis

Question 37

adverse drug event

Answer 37

any untoward medical occurance that may present during treatment with a pharmaceutical product but which does not necessarily have a causal relationship with this treatment ex. falls

Question 38

medication error

Answer 38

any PREVENTABLE event that may cause or lead to inappropriate medication use or patient harm while the medication is in the control of the healthcare professional, patient, or consumer

Question 39

tool used to determine risk of drug interactions for hepatic failure

Answer 39

childs-pugh classification considers bilirubin, albumin, ascites, encephalopathy, prothrombin time

Question 40

important meds to evaluate for in hepatic failure

Answer 40

drugs that depend on hepatic metabolism for clearance high hepatic extraction ration degree of protein binding free drugs have greater effect to target sites benzos, fluoroquinolones, H2 antagonists, loop diuretics

Question 41

renal failure changes

Answer 41

changes in protein binding altered volume of distribution d/t fluid overload or altered tissue binding decreased clearance

Question 42

cockcroft-galt equation

Answer 42

estimates CrCl CrCl = (140-age)(ABW in kg)/72(Scr) females - CrCl * 0.85 ``` Normal = >90 ml/min ABW = actual body weight ```

Question 43

important meds to monitor in renal failure

Answer 43

drugs that may worsen renal function are renally eliminated are metabolized to active/renally eliminated metabolites are highly protein bound

Question 44

CHF changes

Answer 44

decreased blood flow to GI and muscles - decreased absorption decreased interstitial fluid, decreased Vd, decreased hepatic blood flow, decreased clearance

Question 45

drug interactions

Answer 45

occurs when the effects of one drug are altered by the co-administration of another substance

Question 46

phase of pharmacokinetics that causes the most adverse drug reactions

Answer 46

metabolism

Question 47

common inducers of drug metabolism

Answer 47

carbamazepine phenobarbital phenytoin rifampin

Question 48

common inhibitors of drug metabolism

Answer 48

omeprazole trimethoprim metronizadole

Question 49

creatinine clearance for peds

Answer 49

K * L/SCr ``` L = length in cm K = constant SCr= serum creatinine in mg/dL ```

Question 50

do peds require larger or smaller doses than adults?

Answer 50

larger per kg

Question 51

average CrCl for elderly patients

Answer 51

50-80 ml/min

Question 52

creatinine clearance =

Answer 52

(140-age)(ABW) /72(Scr)

Question 53

factors that make meds easy to pass into breast milk

Answer 53

small size weak base low binding lipid soluble