Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Med Year 1 - IMS > Pharmocology > Flashcards

Pharmocology Flashcards

1
Q

What is pharmacokinetics?

A

Non-specific general processes
- absorption from site of administration
- time to onset of effect
- elimination from the body

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

What are the categories of drug names?

A
  • generic name
  • trade or brand name
  • chemical name
  • use name
  • effect name
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the generic name?

A

Approved or official name e.g. Paracetamol

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

What is the trade or brand name? Example with Paracetamol?

A

‘Propietary’ name given to a drug by its pharmaceutical producer e.g. panadol

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

What is the chemical name? Example with Paracetamol?

A

Each drug has its own chemical structure and is given an appropriate chemical name e.g. N-(4-hydroxyphenyl)ethanamide

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

What is the use name? Example with Paracetamol?

A

Commonly drugs are categorised according to the use for which they are prescribed such as anti-hypertensives, contraceptives, anti-inflammatories e.g. pain-killer

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

What is the effect name? Example with Paracetamol?

A

For some drugs, the categorisation relates to the physiological or biological response in the body e.g. pain killer

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

What are the ten routes of administration of drugs?

A
  • Oral
  • intramuscular
  • subcutaneous
  • intravenous
  • buccal
  • transdermal
  • inhalation
  • intrathecal
  • epidural
  • topical
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the advantage of oral administration?

A

Convenient, safe, economical

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

What is the disadvantage of oral administration?

A

Cannot be used for drugs inactivated by 1st pass metabolism or that irritate the gut

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

What is the advantage of intramuscular administration?

A
  • Suitable for suspensions and oily vehicle
  • rapid absorption from solutions
  • slow and sustained absorption from suspensions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the disadvantages of intramuscular administration?

A
  • May be painful
  • May cause bleeding at site of injection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the advantage of subcutaneous administration?

A

Suitable for suspensions and pellets

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

What are the disadvantages of subcutaneous administration?

A
  • cannot be used to deliver large volumes of fluid
  • cannot be used for drugs that irritate cutaneous tissue
  • poses more risk for toxicity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are advantages of intravenous administration?

A
  • bypasses absorption yielding immediate effect
  • 100% immediate bioavailability
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the disadvantage of intravenous administration?

A

Poses more risk for toxicity

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

What are the advantages of buccal administration?

A
  • rapidly absorbed
  • avoids 1st pass metabolism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the disadvantages of buccal administration?

A
  • effective only for low doses
  • drugs must be water and lipid soluble
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the advantage of transdermal administration?

A

Avoids 1st pass metabolism

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

What is the disadvantage of transdermal administration?

A

Effective only for low doses of drug that are highly lipid soluble

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

What is the advantage of inhalational administration?

A

Produce a localised effect

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

What are the disadvantages of inhalational administration?

A
  • drug particles must be the correct size
  • dependent on parient technique
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the advantage of intrathecal administration?

A

Local and rapid effects

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

What are the disadvantages of intrathecal administration?

A
  • requires expert administration
  • May introduce infection/toxicity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the advantage of epidural administration?

A

Provides a targeted effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the disadvantages of epidural administration?

A
  • risk of failure
  • risk of infection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the advantage of topical administrations?

A

Non-invasive and easy to administer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What ate the disadvantages of topical administration?

A
  • poorly lipid soluble nor absorbed via skin or mucous membranes
  • very slow absorption
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

How are oral drugs administered?

A

Taken in through the mouth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How are intramuscular drugs administered?

A

Injection of substance into the muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How are subcutaneous drugs administered?

A

Injected directly under dermis and epidermis layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

How are intravenous drugs administered?

A

Directly delivered into the vein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

How are buccal drugs administered?

A

Drugs applied or administered in the cheek and enter directly into the bloodstream

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

How are transdermal drugs administered?

A

Delivered across the skin into the blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

How are inhalation drugs administered?

A

By inhalation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

How are intrathecal drugs administered?

A

injection into the spinal canal or subarachnoid space so that it reaches the cerebrospinal fluid (CSF)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

How are epidural drugs administered?

A

injected into epidural space around the spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

How are topical drugs administered?

A

Application on body surfaces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What are the advantages of using modified dose forms?

A

improved patient adherence

reduction in incidence and severity of GIT (gastrointestinal) effects

improved control over therapeutic plasma concentrations :
- Improved treatment of chronic conditions in which steady plasma concentration required
- Maintenance of therapeutic action overnight
- Minimise adverse effects associated with high plasma concentrations

40
Q

What are the disadvantages of using modified dose forms?

A
  • Cost more per unit dose than conventional forms
  • Possibility of unsafe over dosage if used incorrectly or in failure of MR tablet
  • Rate of transit through GIT limits the max period for which a therapeutic response can be maintained
  • Variability in physiological factors e.g. GIT pH, enzymes, food etc influence drug bioavailability
41
Q

What can occur due to the incorrect route of administration?

A

Adverse effects and death

42
Q

What are examples of incorrect routes of administration?

A
  • Oral medications given intravenously
  • Intermuscular preparations administered intravenously
  • epidural and intravenous lines mix-up
  • Using intravenous medications given orally
  • Intrathecal administration instead of intravenous administration e.g. Vincristine which is a anti-cancer drug
43
Q

What does ADME stand for?

A
  • Absorption
  • Metabolism
  • Distribution
  • Excretion
44
Q

What is the ADME for an orally administered drug?

A
  • Absorption
  • (First pass) metabolism in the liver
  • Distribution to systemic circulation = pharmacological action in the target tissue, metabolised in the liver and excretion via kidneys, lungs, faeces etc
45
Q

What is the ADME for injected drugs?

A
  • No first pass
  • Distribution to systemic circulation = pharmacological action in the target tissue, metabolised in the liver and excretion via kidneys, lungs, faeces etc
46
Q

What is absorption and the types?

A

Transfer of the drug from the site of administration into the general or systemic circulation
- absorption from the gut (approx. 75% of orally given drug will be absorbed in 1-3 hours)
- Absorption from other routes

47
Q

What are the factors affecting oral absorption?

A
  • Particle size and formulation
  • GIT enzymes/acid
  • GIT motility
  • Physicochemical factors
  • Food
48
Q

What are acids? Dissociation formula?

A

compounds that can dissociate to donate one or more protons

HA <–> H+ + A-

49
Q

What are bases? Formula?

A

Bases are proton acceptors

BH+ <–> B + H+

50
Q

As drugs are either acids or bases what is their degree of ionisation based on?

A

Dependent on the pH of their environment

51
Q

What type of drugs cannot cross the cell membrane?

A

Charged fractions of any drug cannot cross

52
Q

What is distribution?

A

The process by which the drug is transferred reversibly
- from the general circulation into the tissues as concentrations in blood increase
- from the tissues into blood as blood concentrations decrease

53
Q

How does distribution mainly occur?

A

Mainly occurs by passive diffusion of un-ionised form across the cell membrane

54
Q

What is the volume of distribution?

A

Volume of plasma that accounts for total amount of drug

55
Q

What is the volume distribution used for?

A
  • Used to determine the loading dose necessary for a desired blood concentration of a drug
  • Also used for estimating a blood concentration in the treatment of overdose
56
Q

What are factors affecting drug distribution?

A
  • plasma protein binding
  • specific drug receptor sites in tissues
  • regional blood flow
  • lipid solubility
  • disease
57
Q

What does perfusion mean?

A

The passage of fluid through the circulatory or lymphatic system

58
Q

What are some well perfused organs?

A
  • lung
  • adrenals
  • kidneys
  • thyroid
  • liver
  • heart
  • intestines
  • brain
  • placenta
59
Q

What are examples of poorly perfused organs?

A
  • skin
  • skeletal muscle
  • fat
60
Q

What is the formula for drug-protein binding?

A

Drug + protein <–> Drug - protein complex

61
Q

What is drug-protein binding?

A
  • Binding of drugs with albumin and glycoprotein
  • reversible structure
62
Q

What happens if there is administration of a highly bound protein drug to a patient who is already taking a drug that is highly protein bound?

A
  • Results in displacement of drug already bound to protein
  • Produces increased unbound concentration of drug and biological activity
63
Q

What happens with plasma protein binding?

A

If drug is widely distributed in tissues, the increase in unbound drug is rapidly redistributed to body tissues and unbound plasma concentration rapidly returns to negligible amount

64
Q

What happens with unbound plasma concentration if the drug is 20% bound?

A
  • Reduction of 5% in bound drug
  • Unbound plasma concentration increases from 80% to 85% (negligible)
65
Q

What happens with unbound plasma concentration if the drug is 95% bound

A
  • Reduction of 5% in bound drug
  • Unbound plasma concentration increases from 5% to 10% (significant)
66
Q

What are characteristics of passive diffusion?

A
  • Molecules move from an area of high concentration to an area of low concentration
  • Ion channels may facilitate passive diffusion down a concentration gradient
67
Q

What are characteristics of facilitated diffusion?

A
  • Molecules combine with membrane-bound carrier protein
  • Movement still dependent on concentration gradient
    Slightly faster than passive diffusion
68
Q

What are characteristics of active transport?

A
  • Requires energy
  • Molecule transported can be transported against concentration gradient
69
Q

What are characteristics of pinocytosis?

A
  • Molecules engulfed by cell membrane and vesicle formed
  • Vesicle moved into the cell
    Molecule may then be released within the cell
70
Q

What is the process of altering drugs to remove them from the body?

A
  • Activation of inactive drug
  • Production of active drug with increased activity from active drug
  • Inactivation of active drugs
  • Change in the nature of the activity
71
Q

When does metabolism occur?

A

Prior to and during absorption

72
Q

What are the 4 major metabolic barriers before they reach the general circulation?

A
  • Intestinal lumen = digestive enzymes secreted by the mucosal cells and pancreas, certain enzymes break down proteins and stop them from being absorbed
  • Intestinal wall = Rich in enzymes that further metabolise drugs
  • Liver = Major site of drug metabolism
  • Lung = Cells of the lung have high affinity for many drugs and are the site of metabolism for many local hormones.
73
Q

What are the phases of metabolism?

A
  • lipophilic (fat soluble) drug undergoes reaction (oxidation, reduction and hydrolysis)
    = more reactive drug which undergoes reaction (conjugation)
    = hydrophilic (water soluble) drug
    = excreted by kidneys
74
Q

What are the factors (6) affecting drug metabolism?

A
  • First pass effect
  • Hepatic blood flow
  • Liver disease
  • Genetic factors
  • Other drugs
  • Age
75
Q

What is the cytochrome P450 (CYP450) system?

A

A large family of enzymes and individual one is called an isoenzyme. Isoenzymes are named using an agreed method of nomenclature.

76
Q

What is the substrate for cytochrome P450?

A

Drug metabolised by isoenzyme

77
Q

What are the enzyme inducers for the cytochrome P450 system?

A
  • Enhance production of liver enzymes which breakdown drugs
  • faster rate of drug breakdown
78
Q

What are the enzyme inhibitors of the cytochrome P450 system?

A
  • Inhibit production of enzymes which breakdown drugs
  • Reduced rate of drug breakdown
79
Q

How is paracetamol metabolised?

A

Conjugation = paracetamol glucuronide, paracetamol sulphate
Oxidation = N-acetyl-p-benzoquinoneimine (NAPQI) = cysteine/ mercapturate derivatives with glutathione acting on reaction to produce this

80
Q

What is bioavailability?

A

Proportion of a dose that reaches systemic circulation

81
Q

What are the examples of bioavailability with digoxin and atenolol?

A
  • Digoxin 125 micrograms oral dose = 93.75 micrograms in plasma = bioavailability is 75%
  • Atenolol oral bioavailability is 100mg = 45-60mg in the plasma = bioavailability of 46-60%
82
Q

What is bioequivalence?

A

Two or more chemically or pharmaceutically equivalent products (so one can be replaced with another product without causing clinical problems)

83
Q

What does drug elimination via the liver depend on?

A
  • blood flow to the liver
  • activity of the enzymes in the liver
84
Q

How does drug elimination by the liver work?

A

Liver enzymes will chemically alter the drug to form ‘metabolites’ which are:
- inactive or
- equally or more active than the parent drug

85
Q

Elimination of drugs via kidney?

A
  • filtration into bowman’s capsule, go into peritubular capillaries for reabsorption and then secretion from renal vein and also then urinary excretion after it exits peritubular capillaries.
86
Q

What is clearance?

A

Volume of blood/ plasma cleared of drug per unit time
- This includes metabolites as well as renal and biliary clearance
- Clearance does not indicate the amount being removed

87
Q

What is half life (T 1/2)

A

Time taken for the concentration to reduce by 50%

88
Q

What is the substance produced in skeletal muscle which is excreted through the kidneys?

A

Creatinine

89
Q

How is creatinine absorbed and secreted?

A

It is neither passively reabsorbed nor actively secreted

90
Q

What does estimation of creatinine clearance do?

A

Estimates clearance of drugs filtered at the glomerulus

91
Q

What is is the Cockcroft Gault equation and what does it tell you?

A

Estimated Creatinine clearance in mL/min

= (140-Age) x Weight x Constant/ Serum Creatinine

  • Age in years, weight in Kg, serum creatinine in micromol/litre, constant 1.23 in men and 1.04 for women
92
Q

What is absorption like in children vs elderly?

A
  • Unreliable in neonates and greater transcutaneous absorption
  • In general, unchanged
93
Q

What is distribution like in children and the elderly?

A

Fat components of body mass tends to be proportionately greater, acting as a reservoir

94
Q

What is metabolism like in children?

A

Reduced capacity due to immature liver in infants – drug effects prolonged or excessive

95
Q

What is metabolism like in the elderly?

A

Slight reduction due to impaired liver function, so drug effects more pronounced and longer lasting

96
Q

What is excretion like in children?

A

Reduce capacity due to immature kidneys in infants

97
Q

What is excretion like in the elderly?

A

Reduction due to impaired glomerular filtration rate

Med Year 1 - IMS (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions