Pharm Exams 1

Question 1

Properties that determine the onset, intensity, and duration of drug action

Answer 1

Absorption, distribution, metabolism, elimination

Question 2

Absorption

Answer 2

Transfer from site of administration to blood

Question 3

Distribution

Answer 3

Transfer from blood to tissue and target sites

Question 4

Mechanisms of drug absorption

Answer 4

Passive diffusion, facilitated diffusion, active transport, endocytosis

Question 5

Oral administration advantages

Answer 5

*Safest
*Most common
*Convenient and economical

Question 6

Oral administration disadvantages

Answer 6

*limited absorption for some drugs
* food may affect absorption
*patient compliance necessary
*drugs may be metabolized before systemic absorption

Question 7

IV administration advantages

Answer 7

*can have immediate effects
*ideal if dosed large volumes
* suitable for irritating substances
* valuable emergency situations
*dosage titration permissible
*ideal high molecular weight proteins and peptide drugs

Question 8

IV Administration disadvantages

Answer 8

*Unsuitable for oily substances
*bolus injection may result in adverse effects
* most substances must be slowly injected
*strict aseptic techniques required

Question 9

SQ administration advantages

Answer 9

*suitable for slow release drugs
*ideal for some poorly soluble suspensions

Question 10

SQ administration disadvantages

Answer 10

*pain or necrosis if drug irrritating
*unsuitable for drugs administered in large volumes

Question 11

IM administration advantages

Answer 11

*suitable if drug volume moderate
*suitable oily vehicles and certain irritating substances
*preferable to IV if patient must self administer

Question 12

IM Administration disadvantages

Answer 12

*affects certain lab tests (creatinine kinase)
*can be painful
*can cause intramuscular hemorrhage

Question 13

Transdermal (patch) administration advantages

Answer 13

*bypasses first effect
*convenient and painless
*ideal for lipophilic drugs and drugs with poor oral bioavailability
*ideal for drugs that are quickly eliminated from the body

Question 14

Transdermal administration disadvantages

Answer 14

*allergies
*drug must be highly lipophilic
*may cause delayed delivery of drug to pharmacological site of action
*limited to drugs that can be taken in small daily doses

Question 15

Rectal administration advantages

Answer 15

*partially bypasses first pass effect
*bypasses destruction by stomach acid
*ideal in patients who are vomiting or comatose

Question 16

Rectal administration disadvantages

Answer 16

*drugs may irritate rectal mucosa
*not a well accepted route

Question 17

Inhalation administration advantage

Answer 17

*rapid absorption, can have immediate effects
*ideal for gases
*effective for patients with respiratory problems
*dose can be titrated
* localized effect to target lungs: lower doses than oral or parenteral administration

Question 18

Inhalation administration disadvantage

Answer 18

*most addictive route
*patient may have difficulty regulating dose
*some patients may have difficulty using inhalers

Question 19

Sublingual administration advantages

Answer 19

*bypasses first effect
* bypasses destruction by stomach acid
* drug stability maintained because the pH of saliva is relatively neutral
*may cause immediate pharmacological effects

Question 20

Sublingual administration disadvantages

Answer 20

*limited to certain types of drugs
*limited to drugs that can be taken in small doses
*may lose part of the drug dose if swallowed

Question 21

Passive Diffusion

Answer 21

Molecules diffuse from an area of higher concentration to an area of lower concentration
***
Think passing a ball you would throw to someone holding less

Question 22

Facilitated diffusion

Answer 22

Use of transport proteins that move molecules or ions
***
Think of transport proteins as a facility they move through

Question 23

Facilitated diffusion

Answer 23

Use of transport proteins that move molecules or ions

Question 24

Active transport

Answer 24

Molecules diffuse from area of lower concentration to area of higher concentration, require ATP
***
Active=energy, more energy to push through a busy area than into a quiet area

Question 25

Endocytosis

Answer 25

Cells take substances from surrounding environment by engulfing within plasma membrane vesicles *** ENdo ENgulf

Question 26

Factors that influence drug absorption

Answer 26

*pH *blood flow *total surface area *contact time *expression p. Glycoprotein

Question 27

How does pH influence drug absorption?

Answer 27

Influences charge of a drug. Charged drugs do not cross membranes easily and are therefor not well absorbed

Question 28

Weak acids are better absorbed in ___ environment

Answer 28

Acidic

Question 29

Weak bases are better absorbed in ____ environment.

Answer 29

Basic

Question 30

How does blood flow influence drug absorption?

Answer 30

Reduced blood flow= reduced exposure to drug. The concentration gradient is lowered and absorption is reduced by passive diffusion.

Question 31

In the kidney, glomeruli have what type of capillaries?

Answer 31

Fenestrated capillary, the largest filtration slits which allow drugs to pass.

Question 32

What type of capillaries are found in the liver?

Answer 32

Sinusoidal capillary, sinusoids are also discontinuous endothelial cells.

Question 33

The blood brain barrier is a tight barrier that only allows ___ soluble compounds to get past.

Answer 33

Lipid

Question 34

The capillaries of the blood brain barrier are what type?

Answer 34

Continuous capillary

Question 35

How does total surface area influence drug absorption?

Answer 35

Larger surface area allows for better absorption (more space for absorption to take place) and also typically has a larger blood supply for a drug to move down the concentration gradient.

Question 36

Contact time

Answer 36

Longer contact time = increased absorption, shorter contact time=decreased absorption

Question 37

How does the expression of P Glycoprotein influence drug absorption?

Answer 37

Significantly decreased drug absorption by actively pumping drugs back into the intestinal lumen. This limits the amount of drug that can enter the bloodstream from the gut. Essentially a barrier to drug absorption

Question 38

Bioavailability

Answer 38

The rate and extent to which a drug is absorbed after administration.

Question 39

Formula for bioavailability

Answer 39

Area under the curve (non IV)/ Area under the curve by IV

Question 40

Four factors that influence bioavailability

Answer 40

*1st pass hepatic metabolism *Drug solubility *drug stability *drug formulation

Question 41

First pass hepatic metabolism affect bioavailability?

Answer 41

Oral administration requires drugs to go through the liver where they can be metabolized

Question 42

How does Drug solubility influence bioavailability?

Answer 42

A readily absorbed drug must be lipophilic to cross membranes easily

Question 43

How does Drug stability influence bioavailability?

Answer 43

Drugs taken orally must pass the acidic stomach, chemical structure will determine bioavailability

Question 44

How does drug formulation influence bioavailability?

Answer 44

Drug formulation alters chemistry: particle size, coatings, binders tablet, capsule, cream, gel, etc