unit 2 Flashcards

1
Q

bioavailability

A

the amount of drug in the blood that is free to bind at specific target sites to elicit drug action

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

bioavailability depends on:

A

route of administration, absorption and distribution, binding, inactivation (metabolism), excretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

oral delivery

A

advantages - relatively safe, convenient, economical
disadvantages - irritation, nausea, possible destruction by acid or enzymes, complexes with substances in GI tract, relatively slow onset for emergency use, cannot be used in unconscious or uncooperative patient, possible “first-pass” effect, absorption is often irregular and incomplete

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

sublingual delivery

A

advantages - eliminates “first pass” effect, polypeptides are absorbed
disadvantages - drug can be irritating or have bad taste

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

rectal delivery

A

advantages - can be used in an unconscious patient, can be used in vomiting patient, relatively rapid absorption, eliminates first pass effect, convenient for administering drugs to neonates and young children
disadvantages - lack of compliance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

intravenous delivery

A

advantages - complete dose enters the blood, rapid onset of action, controllable rate of absorption, sterile conditions are needed
disadvantages - not easy for self medication, drug must be water soluble, can be painful

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

subcutaneous delivery

A

advantages - by altering the vehicle, the duration of action of many drugs can be prolonged, pellets can be used
disadvantages - irritating drugs cannot be used, absorption cannot usually be controlled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

intramuscular delivery

A

advantages - rapid absorption of drugs in aqueous solutions, can use depot forms and thereby prolong the duration of action of many drugs
disadvantages - irritation is a slight problem, possible injection into blood vessel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

intraperitoneal delivery

A

advantages - rapid absorption
disadvantages - infection and adhesions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

intra-arterial delivery

A

advantages - high concentration in a particular organ or area
disadvantages - difficult access, danger of hemorrhage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

intraspinal delivery

A

advantages - ensure entry into CNS
disadvantages - difficult technique

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

inhalation delivery

A

advantages - very rapid absorption
disadvantages - best for gaseous and volatile liquids, must use aerosol of very fine particle size if drug is not volatile; hard to control the amount of dose absorbed, irritation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

topical delivery

A

advantages - usually produces a local effect without systemic effects, but can also be used for producing systemic effects
disadvantages - possibility of the absorption of a large amount of drug into blood, drug must not be irritating

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

intracranial delivery

A

advantages - primarily for experimental use, parenchymal, intraventricular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

absorption of drugs

A

molecules cross membranes by:
- simple diffusion
- facilitated diffusion
- active transport
-gated channels
- pinocytosis/exocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

factors that determine the passage of molecules across membranes

A

solubility, size, polarization, ionization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

drugs tightly bound to plasma proteins

A

have a limited distribution to tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

tissues involved in metabolisms and excretion

A

tend to concentrate drugs and or drug metabolites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

amine drugs

A

amphetamine, imipramine are usually found in high concentrations in tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

acidic drugs

A

often highly bound to plasma proteins and are not found in very high concentration in tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

the highest concentrations of a drug are not necessarily

A

found in those tissues in which it exerts its action(s)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

the degree of distribution depends on

A

the delivery of the drug by the circulatory system, the ease of the drug crosses membrane barriers and the extent the drug is bound to plasma proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

many drugs bind _____ to albumin and certain globulins in the plasma

A

reversibliy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

many drugs that are highly bound to plasma protein

A

may compete with or displace one another from binding sites. this may be the mechanism of dangerous drug interactions when two or more highly bound drugs are in the blood at the same time

25
Q

plasma protein binding sites

A

may become saturated so that marked increases in the plasma concentrations of the free drug may result after further administration of the drug

26
Q

blood brain barrier

A

primarily composed of endothelial cells of brain capillaries. it functionally acts as a lipid barrier with pores. there are tight junctions between the endothelial cells, and this also restricts the movement of soleus out of the capillaries. lipid soluble drugs pass the blood brain barriers much more readily than do more water soluble compounds.

27
Q

therapeutic range definition

A

the relationship between plasma levels and the therapeutic response, high enough that the drug is effective but not too excessive that it cant be excreted

28
Q

advantages of establishing the therapeutic range

A

patient adherence, avoid toxicity, reduce costs of therapy

29
Q

drug metabolism

A

metabolism converts drug to more hydrophilic compounds - mostly excreted as urine

30
Q

biotransformation reactions phase 1

A

introduce or unmask a chemically functional group - the part of the drug that is reactive

31
Q

biotransformation reactions phase 2

A

combines a functional group with an endogenous substance - something that is made in the body is attached to the functional group
- the liver is pivotal in these phases

32
Q

sites of drug metabolism

A

liver, first pass effect, cellular location is the endoplasmic reticulum, cytochrome

33
Q

enzyme induction

A

can be induced so there are more enzymes available, as there are more enzymes present it can be metabolized quicker - this can lead to build up a tolerance to the drug

34
Q

drugs often cross reaction

A

alcohol might induce enzymes in an alcoholic that has an impact on a specific drug that they take

35
Q

prodrugs

A

not active in the form that they are given, they need to be metabolized before they are active

36
Q

drug excretion

A

important for terminating drug action, various routes, but kidney is primary

37
Q

renal excretion

A

filtration, diffusion, active transport

38
Q

renal excretion can be increased by:

A

increasing urine volume, changing the pH of urine, increasing blood flow to kidneys

39
Q

other routes of excretion

A

liver, GI tract, lungs, mammary glands, salivary glands, sweat glands

40
Q

pharmacodynamics

A

how the drug interacts at a cellular level

41
Q

receptor theory

A

the application of receptor models to explain drug behavior
- concept of a receptor was introdued in the early 1900s

42
Q

ligand

A

a molecule that binds to a receptor with some selecitivty

43
Q

receptor agonist

A

a molecule that binds to a receptor to produce a biological response

44
Q

receptor antagonist

A

a molecule that binds to a receptor and blocks or dampens a biological response

45
Q

concept of a receptor

A

receptors largely determine the quantitative relations between does or concentrations of drug and pharmacologic effects, receptors are responsible for selectivity of drug action - the confirmation, the shape of the drug is important
- receptors mediate the actions of pharmacological antagonists

46
Q

dose response

A

therapeutic index = lethal dose 50/effective does 50

47
Q

mechanisms of producing desired and toxic effects

A

beneficial and toxic effects mediated by same receptors in the same tissues, beneficial and toxic effects mediated by identical receptors but in different tissues or by different effector pathways, mediated by different types of receptors

48
Q

idiosyncratic drug response

A

a genetically determined abnormal response to a chemical

49
Q

hyporeactive

A

resistance to respond to a drug

50
Q

hyperreactive

A

response to a very low dose (innate)

51
Q

hypersensitivity

A

allergic or immunologic response

52
Q

tolerance

A

decreased responsiveness that is acquired

53
Q

sensitization

A

acquired enhanced responsivess to a drug

54
Q

supersensitivity

A

results from denervation or antagonist treatment

55
Q

tachyphylasic

A

decreased responsiveness that is acquired rapidly

56
Q

cross tolerance

A

tolerance to one drug that results in tolerance to another

57
Q

sex differences and drug action

A

related to basal metabolism rate, differences in relative amounts of different tissues, women on oral contraceptives metabolize drugs at a slower rate

58
Q

active transport

A

the movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy

59
Q

agonist

A

a drug or substance that binds to a receptor inside a cell or on its surface and causes the same action as the substance that normally binds to the receptor