Brainscape's Knowledge GenomeTM

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


See full index

Year 1 Semester 2 > Pharmacology > Flashcards

Pharmacology Flashcards

1
Q

What are the main actions of NSAIDs

A
  • Anti-inflammatory
  • Analgesic
  • Anti-pyretic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the primary action of NSAIDs?

A

-Inhibit prostaglandin biosynthesis by direct action on cyclo-oxygenase enzymes

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

What are the two main mechanisms by which NSAIDs inhibit cyclo-oxygenase (COX)?

A
  • An irreversible, time dependent inhibition of the enzyme

- A rapid, reversible competitive inhibition of the enzyme

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

Describe aspirin’s mechanism of action

A
  • inactivates the enzyme
  • aspirin acetylates the alpha-amino group of the terminal serine of the enzyme forming a covalent bond
  • further synthesis of prostaglandins requires synthesis of new enzyme
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe ibuprofen’s mechanism of action

A
  • Binds reversibly to the enzyme

- Competes with natural substrate, arachidonic acid

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

What are prostaglandins?

A
  • Called prostaglandins because it was believed that they originated from the prostate gland
  • Family of compounds - PGE2 and PGF2a were the first ones isolated and structures determined
  • Generated in tissues from a precursor (arachidonic acid) by cyclo-oxygenase enzymes - thromboxanes, prostaglandins and leukotrienes are all products of arachidonic acid metabolism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the two main types of cyclo-oxygenase?

A

COX-1:

  • Constitutive -expressed normally and regularly in a wide range of tissues
  • Important in maintaining GIT integrity

COX-2:

  • Inducible
  • Involved in inflammatory response
  • Implicated in cancer development
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the role of prostaglandins in inflammation?

A

Inflammation always accompanied by release of prostaglandins

  • Predominantly PGE2 but also PGI2
  • PGD2 from mast cells

PGE2, PGI2 and PGD2

  • Act as potent vasodilators
  • Also synergise with other inflammatory mediators (e.g histamine and bradykinin)
  • Potentiate histamine and bradykinin actions on postcapillary venule permeability and pain sensory nerves
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does anti-inflammatory action work on prostaglandins?

A

Prostaglandins are important mediators of inflammation

  • Particularly vasodilation and resultant oedema
  • Less effect on cellular accumulation or migration

Therefore NSAIDs only affect aspects of inflammation in which prostaglandins play a significant part. NSAIDs can reduce many of the local signs and symptoms of inflammation i.e redness, heat, swelling, pain

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

What anti-pyretic effects do NSAIDs have?

A

Body temperature is regulated by the hypothalamus

  • fever occurs when the hypothalamic thermostat ‘set point is raised
  • bacterial endotoxins cause release of factors (e.g interleukin 1) from macrophages
  • interleukin 1 causes generation of prostaglandins in the hypothalamus (PGEs)
  • prostaglandins increase the thermostat set point

Therefore NSAIDs act by preventing the formation of prostaglandins and prevent the rise in temperature - no effect on normal body temperature

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

Describe the analgesic effect of NSAIDs

A

Inflamed regions painful due to histamine and bradykinin release

  • activate nocioceptive afferent nerve terminals
  • register a painful stimulus

Prostaglandins sensitise nocioceptive nerves to these compounds

Therefore by preventing prostaglandin production NSAIDs prevent sensitisation to pain-producing compounds

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

What family does aspirin belong to?

A

Salicylates

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

Give some details about aspirin

A
  • pro drug (acetylsalicylic acid) - can directly acetylate COX enzyme
  • Also metabolised to active compound (salicylic acid) by plasma and tissue esterases
  • Salicylate found in plasma within 30 mins
  • Peak plasma concentration within 1-2 hours
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Give some details about aspirin

A
  • pro drug (acetylsalicylic acid) - can directly acetylate COX enzyme
  • Also metabolised to active compound (salicylic acid) by plasma and tissue esterases
  • Salicylate found in plasma within 30 mins
  • Peak plasma concentration within 1-2 hours
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are some unwanted effects of salicylates?

A
  • Stomach: bleeding, ulcers
  • Systematic: tinnitus, dizziness, impaired hearing, nausea, vomiting, hypersensitivity
  • Metabolic changes: acid/base balance affected
  • Haemostasis: blood coagulation affected through and action on platelets
  • CNS effect: stimulation initially, ultimately coma and respiratory depression
  • Renal: insufficiency in susceptible patients and with chronic use and overdose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe propionic acids and give some examples

A
  • Not prodrugs
  • Well absorbed
  • Last for 4-6 hours
  • e.g ibuprofen, naproxen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe propionic acids and give some examples

A
  • Not prodrugs
  • Well absorbed
  • Last for 4-6 hours
  • e.g ibuprofen, naproxen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is an example of a fenamate?

A

Mefenamic acid

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

What are some features of paracetamol (acetaminophen)?

A
  • Good analgesic and antipyretic activity
  • Poor anti-inflammatory
  • Well tolerated in GIT
  • Weak COX inhibitor - may be selective inhibitor of CNS-specific COX, COX-3
  • Given orally, well absorbed - peak plasma conc in 30-60 mins - half life in plasma is 2-4 hours for therapeutic doses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Explain side effects of paracetamol

A

Fewer side effects than other NSAIDs (perhaps due to its selectivity for COX enzymes)

Major issue is hepatotoxicity due to overdose

  • Normally inactivated in the liver by glucoronate and sulphate conjugation
  • When these enzymes are saturated, toxic metabolites are formed
  • Result can be hepatic necrosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe coxibs and give an example

A
  • Selective COX-2 inhibitor
  • Used for osteoarthritis and rheumatoid arthritis
  • Restricted for when traditional NSAIDs produce too severe GIT side effects
  • Cardiovascular risk needs to be assessed
  • e.g celecoxib
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What clinical analgesic uses of NSAIDs are there?

A
  • Headache
  • Dysmennorhea
  • Backache
  • Bony metastases of cancers
  • Postoperative pain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Which NSAIDs are used for short term analgesia?

A

Aspirin, paracetamol, ibuprofen

22
Q

What longer lasting NSAIDs are used for chronic pain?

A

Naproxen, diclofenac

23
Q

Define pharmacology

A

Origin, nature, chemistry, effects and uses of drugs

24
Q

Define toxicology

A

Study of the adverse effects of chemical, physical or biological agents

25
Q

Define pharmacodynamics

A

What the drug does to the body

26
Q

Define pharmacokinetics

A

What the body does to the drug

27
Q

Why is pharmacokinetics important?

A
  • Explain how dose recommendations in inserts are arrived at
  • Identify possible drug interactions
  • To adjust strategies such as therapeutic dose monitoring
  • To safely administer drugs when urgency is required
  • Predict the influence of disease on drugs
28
Q

What are the four main stages of pharmacokinetics?

A
  • Absorption
  • Distribution
  • Metabolism
  • Excretion
29
Q

What are some routes of drug administration?

A
  • Oral
  • Sublingual
  • Inhalation
  • Topical
  • Transdermal
  • Intramuscular
  • Intravenous
30
Q

What are some advantages and disadvantages of oral administration?

A
  • Advantage: convenient

- Disadvantage: first pass effect, many variables and barriers

31
Q

What are some advantages and disadvantages of sublingual administration?

A
  • Advantage: no first-pass effect

- Disadvantage: inconvenient, small dose limit, taste

32
Q

What are some advantages and disadvantages of inhalation administration?

A
  • Advantage: fast, rapid delivery to blood

- Disadvantage: requires special properties of drug

33
Q

What are some advantages and disadvantages of topical administration?

A
  • Advantage: convenient, localised

- Disadvantage: only local

34
Q

What are some advantages and disadvantages of transdermal administration?

A
  • Advantage: prolonged release

- Disadvantage: skin very effective barrier

35
Q

What are some advantages and disadvantages of intramuscular administration?

A
  • Advantage: rapid for aqueous, slow for oil

- Disadvantage: painful, requires trained personnel

36
Q

What are some advantages and disadvantages of intravenous administration?

A
  • Advantage: direct, total dose, rapid

- Disadvantage: requires professional, infection risk, rapid response

37
Q

What is bioavailability?

A

Fraction of unchanged drug that reaches systemic circulation

38
Q

What bioavailability does IV injection give?

A

100%

39
Q

What four ways can small molecules cross cell membranes?

A
  • Diffusing directly through the lipid
  • Diffusing through aqueous pores
  • Transmembrane carrier protein
  • Pinocytosis
40
Q

What are the main drug properties that affect absorption?

A

Lipophilicity and ionisation

41
Q

What are the factors that affect distribution of a drug?

A
  • Degree of drug ionisation
  • Lipid solubility
  • pH of compartments
  • Cardiac output and blood flow
  • Capillary permeability
  • Plasma protein binding
42
Q

Give a brief description of phase I metabolism in the liver

A
  • Generally oxidation, reduction or hydrolysis - introduce/reveal a reactive chemical group
  • Products often more reactive
43
Q

Give a brief description of phase II metabolism in the liver

A
  • Synthetic, conjugative reactions

- Hydrophilic, inactive compounds generated

44
Q

Describe cytochrome P450 enzymes

A
  • Mixed function monooxygenases
  • Throughout the body, extensively in the liver
  • 57 human genes coding for CYP P450 enzymes
45
Q

What are the functions of cytochrome P450 enzymes?

A
  • Biosynthesis of steroids, fatty acids and bile acids

- Metabolism of endogenous and exogenous substrates

46
Q

Give a summary of drug metabolism

A
  • Aim is to produce metabolites that can be excreted
  • Mainly occurs in the liver, metabolites can be active or toxic
  • Genetic variability in metabolic enzymes occurs, and expression of metabolic enzymes can be induced and/or inhibited
  • Competition for metabolic enzymes occurs and metabolic pathways can be saturated
  • Metabolism can affect the bioavailability of drugs
47
Q

Which type of drugs are eliminated more readily?

A

Hydrophilic over lipophilic

48
Q

What are some possible sources of excretion?

A
  • Breath
  • Urine
  • Saliva
  • Perspiration
  • Feces
  • Milk
  • Bile
  • Hair
49
Q

Which organs are the most important in the elimination of drugs and their metabolites?

A

Kidneys

50
Q

What is the Cmax of a drug?

A

Maximum concentration of a drug in plasma following a single dose

51
Q

What is the Tmax of a drug?

A

The time taken to reach the peak plasma concentration

52
Q

What is the absorption half life of a drug?

A

The amount of time taken to get to half the peak plasma concentration

53
Q

What is plasma clearance half life/elimination half life?

A

The amount of time taken to half a drug’s plasma concentration

Year 1 Semester 2 (26 decks)

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