Facts

Question 1

3 most important properties of drugs

Answer 1

effectiveness - has to do what it is supposed to do
safety - there is no completely safe drug
selectivity - one that elicits only desired effects - there is no such thing (all have side effects)

Question 2

other desired properties

Answer 2

reversibility
predictability
ease of administration
freedom from drug interactions
low cost
chemical stability
possession of a simple generic name

Question 3

reversibility

Answer 3

drug actions to subside within an appropriate time (aside from things like antibiotics)

Question 4

predictability

Answer 4

knowing how someone will respond - not guaranteed because everyone is different

Question 5

ease of administration

Answer 5

has two benefits
1 it can enhance patient adherence
2 it can decrease risk. patient more likely to stick to dosing schedule (1 dose per day rather than multiple)

Question 6

freedom from drug interactions

Answer 6

not have bad interactions when taken with other drugs

Question 7

low cost

Answer 7

drugs can be very expensive

Question 8

chemical stability

Answer 8

an ideal drug would retain its activity indefinitely instead of expiring after time

Question 9

possession of a simple generic name

Answer 9

generic names are complex. an ideal drug would have one that is easy to remember

Question 10

factors that determine the intensity of a drug response

Answer 10

administration - dosage, route, timing, adherence, errors
pharmacokinetics - absorption, distribution, metabolism, excretion
pharmacodynamics - drug-receptor interaction, patient’s functional state, placebo effects

Question 11

5 rights

Answer 11

right..
1 drug
2 patient
3 dose
4 route
5 time

Question 12

drug absorption affecting factors

Answer 12

rate of dissolution
absorbing surface
blood flow - high blood flow = high absorption
lipid solubility of drug - high solubility = faster absorption
pH partitioning - acidic drugs - alkaline side of membrane, basic drugs - acidic side of membrane

Question 13

parenteral meds benefits and problems

Answer 13

benefits:
no barriers
rapid onset
can give large amounts of fluids
circulated quickly

problems:
cost, convenience
not reversible
infection, embolism
must be water soluble to be injected

Question 14

intramuscular (IM) absorption rate

Answer 14

10-30 minutes

Question 15

subcutaneous (SQ) absorption rate

Answer 15

blood flow not as good as IM so may be slower

Question 16

enteral (by mouth via GI) barriers to absorption

Answer 16

1 epithelial cells of GI tract lining (biggest barrier)
2 endothelial cells of capillary wall

Question 17

factors affecting enteral (by mouth) absorption

Answer 17

solubility
GI pH
gastric emptying
stomach contents
other drugs
drug coating

Question 18

disadvantages of enteral (by mouth)

Answer 18

variable absorption
inactivation by food, other drugs, gastric acidity, liver (first pass)
patient must be awake, alert
GI upset

Question 19

other routes of administration

Answer 19

topical - skin, eyes, ears, nose, mouth, rectum, vagina
inhaled
rectal suppositories
vaginal suppositories
direct injection - joints, heart, CNS

Question 20

distribution of drug affected by

Answer 20

1 blood flow
2 ability to exit the vascular system
3 ability to enter cells

Question 21

drugs that are/have _______ can cross the blood brain barrier

Answer 21

lipid soluble
have a transport system

Question 22

an important consequence of drug-protein binding

Answer 22

restriction of drug distribution

albumin (most important binding protein) is too large to get through capillary wall, so it stays in the blood stream
drugs that bind albumin cannot leave blood stream either until bond is broken

Question 23

most drug metabolism takes place in

Answer 23

the liver

Question 24

results of drug metabolism

Answer 24

accelerated renal excretion of drugs
drug inactivation
increased therapeutic action
activation of prodrugs - inactive as administered and is converted into active form via metabolism
increased toxicity
decreased toxicity

Question 25

factors that affect metabolism rate

Answer 25

age - infants and elderly are slower
genetic polymorphism - varies by race, geographic location

Question 26

drugs can exit the body in

Answer 26

urine, bile, sweat, saliva, breast milk, and expired air

Question 27

the most important organ for excretion is

Answer 27

the kidney

Question 28

steps in drug elimination

Answer 28

1 filtration
2 reabsorption (lipid soluble drugs undergo passive reabsorption from tubule back into blood)
3 secretion (pumps move drugs from blood into urine)

Question 29

factors affecting secretion

Answer 29

pH (manipulating pH can hasten the drugs elimination - for poisoning and toxic doses of meds)
competition for active tubular transport (can only transport so much at a time - competition might prolong the effects of drugs)
age (newborn’s have limited capacity to excrete drugs because of undeveloped kidneys - old age causes renal function decline which decreases excretion of drugs)

Question 30

plasma drug level used to predict therapeutic or toxic affects because

Answer 30

it is hard to measure drug concentration at sites of action. easier to calculate therapeutic or toxic affects based on blood plasma

Question 31

drug-receptor interactions

Answer 31

1 drugs most often act as the body’s own receptor sites for hormones, neurotransmitters, etc.
2 drug can only mimic or block actions of substance that normally interact with that receptor
3 drugs can not give cells new function
4 drug interaction with a receptor is like a lock and key (very specific)

Question 32

variability in drug responses

Answer 32

amount of drug required for therapeutic response can vary
not always easy to predict
ED50 - standard dose, fine tuned for each patient