Lecture 2: Routes of Drug Administration

Question 1

t/f route of administration

has a dramatic effect on the time course of a drug in the body

Answer 1

treu

Question 2

what is the most common route of drug delivery?

Answer 2

oral

Question 3

what are the 3 types of enteral drug administration?

Answer 3

1. oral
2. buccal / sublingual
3. rectal

Question 4

what is the primary absorption site for oral drugs?

Answer 4

small intestine

Question 5

drug absorption and effects of oral drugs are determined by what three things?

Answer 5

1. physiological factors
2. chemical/physical factors
3. drug formulation

Question 6

what are the physiological factors that can influence oral drug absorptin>

Answer 6

pH, gastric emptying

Question 7

what are the chemical/physical factors that can influence oral drug administration?

Answer 7

molecular weight and ionization

Question 8

do liquids or solids tend to be better absorbed when given by the oral route?

Answer 8

liquids

Question 9

why does molecular weight and ionization matter in absorption>

Answer 9

they have an effect on how well a drug is moved across membrane

Question 10

blood draining from gastrointestinal organs and spleen flows into the ___ circulation and ___(organ) before reaching the general circulation

Answer 10

portal; liver

Question 11

blood draining from the intestines, stomach, pancreas, and spleen drains into the __ and will then move to the __ where drugs can be subject to metabolism before reaching the systemic circuit

Answer 11

portal vein; liver.

Question 12

first pass metabolism describes the metabolism of a drug as it passes through the ____ and ___ before reaching the __

Answer 12

intestinal wall and liver; systemic circuit

Question 13

first pass metabolism can reduce __

Answer 13

amount of active drug that reaches the systemic circuit

Question 14

t/f metabolism can both activate and inactive drugs

Answer 14

true

Question 15

the buccal route is the location of the __

Answer 15

membranes of the cheeks and behind the lips

Question 16

the sublingual route is the location of the __

Answer 16

under the rogue

Question 17

drugs in the buccal/sublingual route first pass through the __ epithelium to the ___ membrane which is reach in __ and __ that will transport the drug directly to the systemic circuit

Answer 17

stratified oral; submucosal; collagen and blood vessels

Question 18

are drugs that are administered buccally and sublingually subject to first pass metabolism?

Answer 18

no

Question 19

nicotine absorbs better in the mouth than the stomach, why is this?

Answer 19

pH

Question 20

both the buccal and sublingual routes are ___, but the sublingual space has a ___

Answer 20

non-keratinized; thinner epithelium

Question 21

what are 4 properties of the SL route that increase absorption?

Answer 21

1. thinner epithelium
2. immersion in saliva
3. higher blood flow
4. less propensity to swallow

Question 22

what are the 3 rectal veins that drain blood from the rectum?

Answer 22

superior, middle and inferior rectal veins

Question 23

the superior rectal veins drains into the ___ and therefor __ undergo 1st pass metabolism

Answer 23

portal vein; does

Question 24

the middle and inferior rectal veins drains into the __ and therefor __ undergo 1st pass metabolism

Answer 24

vena cava; do NOT

Question 25

what is a benefit of rectal administration?

Answer 25

reduces 1st pass metabolism (but does not completely eliminate)

Question 26

drug absorption in the rectal route is highly dependent on the ___ of the drug administered as this determines which veins are likely to absorb the drug

Answer 26

placement within the rectum

Question 27

what are the 3 types of parenteral admin?

Answer 27

1. intravenous 2. subcutaneous 3. intramuscular

Question 28

list 5 advantages of intravenous administration

Answer 28

1. no barrier to absorption 2. rapid achievement of high drug concentration 3. rapid onset of action 4. precise delivery and controlled dose 5. can deliver large volumes

Question 29

subcutaneous injects into the __

Answer 29

fatty tissue under the skin

Question 30

absorption form SC/IM sites is said to be __ rate limited, meaning it depends on __

Answer 30

perfusion, rate of blood flow away from the site

Question 31

blood vessels have pores called ___ that allows the ___ diffusion of drug rapidly

Answer 31

fenestrae, passive

Question 32

is there any barrier to blood absorption in the SC/IM route?

Answer 32

no

Question 33

oral administration absorption is ___ rate limited

Answer 33

permeability

Question 34

the __ supply impacts the effects of SC drugs

Answer 34

vascular supply

Question 35

at the IM site of administration, there is little impedance to movement of a drug into blood flow, even for __ and __ drugs

Answer 35

polar and ionized

Question 36

when administered IM, drugs are absorbed independently of ___and molecular size up to ___ g/mol

Answer 36

pKa (ionization); 5000

Question 37

which has higher blood flow, gluteal or deltoid?

Answer 37

deltoid

Question 38

if a drug is ____g/mol or larger, it is too large to be absorbed through the fenestra of the BV, therefore must enter through the ___ pathway

Answer 38

20 000; lymphatic

Question 39

lymph flow is much ___ than blood flow, absorption timeline of __

Answer 39

slower; several hours

Question 40

what are two benefits of drug distribution through the lymph?

Answer 40

slow transport allows for amount to be maintained at near constant amount and reducing the number of times it needs to be administered

Question 41

what are the 4 topical delivery routes?

Answer 41

1. percutaneous 2. ocular 3. nasal 4. inhalation

Question 42

what is percutaneous delivery?

Answer 42

delivering a drug to the place immediately below the point of application

Question 43

the percutaneous route if mainly designed for __ effects (ex: ___), but can also be used for ___ (ex:___)

Answer 43

local: hydrocortisone; systemic: nicotine and nitroglycerine patches

Question 44

what is a benefit of the percutaneous route?

Answer 44

can administer directly to desired site while minimizing the side effects of it affecting the body systemically

Question 45

percutaneous is also known as __

Answer 45

transdermal

Question 46

provide an example of a drug that is delivered transdermally to have systemic effects

Answer 46

fentanyl (applied to skin too treat systemic pain)

Question 47

why might lidocaine for pain relief be given percutaneously?

Answer 47

in large doses, it can be linked to toxicity and acadian arrest, therefore want to eliminate large systemic exposure

Question 48

list 4 factors that may affect variability of transdermal patches

Answer 48

1. temperature 2. sweating 3. age 4. skin thickness

Question 49

for fentanyl, an increase in temperature does what to the absorption rate?

Answer 49

increases

Question 50

ocular admin is reserved for only __ delivery

Answer 50

local

Question 51

give an example of a drug that is delivered ocularly an what it is used to treat

Answer 51

topical agents (beta antagonists) that reduce intraocular pressure in glaucoma

Question 52

beta antagonists can adversely affect ___ / __ function in patients with __, ___. ___

Answer 52

cardiac/pulmonary; heart failure, bradycardia, COPD

Question 53

nasal drug administration has historically been used to __ delivery, but recent investigations indicate that it may be useful for __ delivery

Answer 53

local; systemic

Question 54

nasal exposure may allow for __ exposure due the the ___ channels

Answer 54

brain exposure; olfactory

Question 55

give an example of a nasally administersed drug that has been traditionally given IV, but has shown to reach effective concentration in 10 min through nasal route

Answer 55

midazolam

Question 56

what is a benefit of being able to administer via nose rather than IV

Answer 56

less invasive

Question 57

the inhalation route is used to treat diseases of the __

Answer 57

lungs

Question 58

administration via the inhalation route minimizes the __while lowering the __

Answer 58

required dose; systemic concentration and associated risk

Question 59

what makes the lungs a great delivery system? 3

Answer 59

1. rich blood supply to areolar epithelium for gas exchange 2. highly permeable membrane 3. provides favourable conditions for rapid and efficient absorption of systemically acting agents such as volatile aneshtetic s

Question 60

nicotine is absorbed fastest through which route? what is the impact of this?

Answer 60

inhalation, makes smoking more addictive than chewing

Question 61

give an example of topical inhalation drug

Answer 61

corticosteroids