03- Development of Dosage Regimen

Question 1

4 pathways

Answer 1

bioavailability
distribution
apparent volume
elimination

Question 2

4 pathways control

Answer 2

concentration of drug in plasma
onset, peak, and duration of drug actions
drug dosing interval

Question 3

onset

Answer 3

rate of drug absorption and distribution

Question 4

Intensity

Answer 4

amount of drug absorbed and distributed

Question 5

duration

Answer 5

rate of drug metabolism and elimination

Question 6

define bioavailability

Answer 6

Fraction of administered dose that reaches plasma in chemically unchanged and biologically active form

Question 7

factors affecting bioavailability (4)

Answer 7

1. first-pass hepatic metabolism
2. Chemical instability
3. Drug formulation
4. Plasma protein binding (albumin, alpha-1 acid glycoproteins)

Question 8

true or false: Orally administered drugs rarely have 100% bioavailability

Answer 8

true

Question 9

Distribution

Answer 9

Process by which a drug reversibly leaves bloodstream and enters body tissues

Question 10

what can impact distribution

Answer 10

impacted blood flow, solubility of drug, organ size, etc.

Question 11

apparent volume of distribution

Answer 11

Volume into which a drug is known to distribute within the body (Vd)
(amount of drug in body)/(plasma drug [ ])

Question 12

why does apparent volume of distribution calculate?

Answer 12

dose of drug required to achieve specified concentration of drug in plasma

Question 13

true or false: therapeutic concentration is always a 2 digit number

Answer 13

false: range

Question 14

therapeutic response is achieved if plasma [ ]….

Answer 14

within range

Question 15

little effect is achieved if plasma [ ]….

Answer 15

is below range

Question 16

toxicity and adverse effects occur if plasma [ ]….

Answer 16

is above range

Question 17

what is the purpose of a loading dose?

Answer 17

Used to quickly achieve a high therapeutic plasma [] of drug ([D]o)

Question 18

true or false: the calculation for weight of drug administered to the patient (Wd = [D]o x Vd) can be used to calculate loading dose only

Answer 18

false: can be used for loading dose OR single dose of drug

Question 19

where in therapeutic range do you target for single dosing?

Answer 19

middle of range

Question 20

why are dosing regimens not a static phenomenon?

Answer 20

Rate at which drug is metabolized and eliminated form body plays a big role in determining how plasma drug concentrations can be maintained within therapeutic range over time

Question 21

what should you consider when administering a single dose of medication vs. a medication taken for a longer period of time?

Answer 21

Rate of dose elimination if not taken into consideration when calculating loading dose or single dose of drug

Question 22

if a patient has a faster metabolism will they need to be given medications more or less often?

Answer 22

more often. shorter half life for drugs

Question 23

plateau principle

Answer 23

multiple drug doses can achieve a steady state concentration in the blood if the frequency of drug administration is timed equally

Question 24

maintenance dose

Answer 24

Amount of drug (dose) required to maintain plasma [ ] of drug within therapeutic range
Should always be smaller than loading dose

Question 25

clearance

Answer 25

Volume of plasma completely cleared of a drug per unit of time (L/h)

Question 26

clearance is related to what other variables?

Answer 26

half life (elimination rate constant) and apparent volume of distribution

Question 27

doing interval

Answer 27

amount of time between doses