Pharmacology Flashcards
lecture 1
1
Q
The Study of how the body handles drugs
A
Pharmacokinetics (PK)
2
Q
What the drugs do to the body and how they do it
A
Pharmacodynamics (PD)
3
Q
What are the 4 stages of drug disposition?
A
Administration/ Absorption
Distribution
Metabolism
Excretion
4
Q
movement from the site of administration into the plasma
A
absorption
5
Q
Factors that affect the rate and degree of absorption? (6)
A
- lipid solubility (molecular weight ad pKA)
- surface area
- gut content
- GI transit time
- Blood flow to site of administration
- drug interaction
6
Q
Where are most drugs absorbed?
A
small intestine
7
Q
Approximately 75% of a drug given orally is absorbed ….?
A
1-3 hours
8
Q
Main routes of drug administration
A
-Oral(po) ― Sublingual ― Rectal ―Application to the epithelial surfaces (e.g. skin, cornea and vagina) ― Inhalation(pulmonary) ― Injection
9
Q
Factors that affect the movement of drugs (equilibrium pattern of distribution between the compartments):
A
-Permeability across tissue barriers ― Bindingwithincompartments ― pHpartition ― Fat:waterpartition ― Blood flow to the tissue
10
Q
Factors affecting drug distribution:
A
Plasma protein binding
11
Q
in plasma protein binding… what is found in mainly acidic drugs?
A
albumin
12
Q
in plasma protein binding… what is found in mainly basic drugs?
A
α1-acid glycoprotein
13
Q
What fraction of drug exerts pharmacological effects
A
only the free or unbound drug fraction
14
Q
process of chemical modification of drugs by enzymatic reaction within the body.
A
Drug Metabolism or biotransformation
15
Q
What is the primary site of drug metabolism?
A
liver
16
Q
The fraction (F) of the dose which proceed unaltered from the site of administration to the systemic circulation (blood plasma)
A
bioavailability
17
Q
Interindividual variability that is not related to drug preparation is mainly caused by change in:
A
― Enzymatic activity of gut wall or liver (first- pass metabolism)
― Gastric pH
― Intestinalmotility
18
Q
What profoundly reduces bioavailability of a drug (that’s taken orally)
A
first-pass metabolism
19
Q
T or F: bioavailability neglects the rate of absorption
A
True
20
Q
T or F: Bioavailability only considers the total fraction of a drug that reaches the systemic circulation
A
True
21
Q
Most drugs are excreted through the…
A
kidneys
22
Q
Why can urine tests use to detect drugs?
A
because 20-30% of drugs are mainly excreted in the active form and are unchanged (such as drugs illicit)
23
Q
Time taken for drug concentration(Cp) to decrease by half
A
Elimination half-life (t1/2)
24
Q
The longer the half life….the longer the
A
plasma concentration in the therapeutic range
25
t1/2 is directly proportional to...
volume of distribution and inversely proportional to total clearance
26
flowchart of oral administration (pharmacokinetics)
1) oral administration
2) GIT absorption: active transport/ passive diffusion
3) portal circulation (first pass metabolism)
4) blood vessels bioavailability (distribution)
5) renal excretion
27
What the dugs do to the body and how they do it
pharmacodynamics (PD)
28
COORDINATE THE FUNCTION AND RESPONSES OF ALL DIFFERENT CELLS IN THE BODY
receptors
29
protein molecules that when activated by transmitters/hormones/drugs mediate a biological effect.
receptors
30
What are receptors important for?
chemical signaling between/within cells
31
4 types of receptor types
1) ligand-gates ion channels (ionotropic)
2) G protein-coupled receptors (metabotropic)
3) kinase-linked receptors
4) nuclear recepts
32
The most common protein targets
a) receptors
b) ion channels
c) enzymes
d) transporters
33
drugs that occupy receptors and activate them
agonists
34
Drugs that occupy receptors but do not activate them (can block agonists)
antagonists
35
maximal response a drug can produce
Emax (efficacy)
36
concentration needed to produce a 50% maximal response
EC50 (potency)
37
the lower the potency of a drug the higher....
the dose needed
38
how is a drugs safety determines?
therapeutic index (TI)
39
What is compared in therapeutic effect?
therapeutic effective dose to the toxic dose of a pharmaceutical agent
40
drug dose that produces a therapeutic response in 50% of the population
ED50
41
Drug dose that produces a toxic response in 50% of the population
TD50
42
therapeutic index (ratio)
TD50/ ED50
43
The higher the number on the therapeutic index=?
less toxic
44
What are predictable adverse drug reactions?
- overdose
- side effect
- withdrawal effect
45
Consequence of the main pharmacological • effect of the drug or its known PK. (low therapeutic effect)
predictable adverse effects
46
Examples of predictable adverse effect drugs?
- anticoagulants
- lithium
- hypoglycaemic
47
Unrelated to the known pharmacological action of the drug (off-target)-more serious and unique to an individual
unpredictable adverse drug reactions
48
What are the underlying mechanisms for drug to drug interactions?
- behavioral (altered compliance)
- pharmacokinetic (altered concentration)
- pharmaceutic (outside the body)
- pharmacodynamic (altered effect)
49
What are drugs able to interact with?
- drugs
- food
- supplements
- medical conditions
50
Drugs with similar actions
| ex) alcohol and benzodiazepine (CNS depressant)
additive effects
51
change is concentration leading to clinical consequences
- altered bioavailability
| - altered metabolism (prodrugs)
52
any substance, including any drug, that has the capacity to harm a living organism
poison
53
What are the stages of drug development?
- drug discovery
- preclinical development
- clinical development (phase I-III)
- regulatory approval
- phase IV
54
Who is checking your medicines?
AUS:
USA:
TGA IN AUSTRALIA (therapeutic goods Administration)
- FDA IN USA
55
Two categories of medicine?
- registered medicine
| - listed medicine
56
* higher risk medicines that are registered on the ARTG • evaluated for quality, safety and efficacy
* Product Information is approved by the TGA
registered medicines
57
* lower risk medicines that are listed on the ARTG
* contain pre-approved, low risk ingredients
* Evaluated for quality and safety
* can only make limited claims and cannot imply that they will be useful in the treatment or prevention of serious illnesses
listed medicines
58
Are these a registered medication:
- prescription medicines
- OTC medicines
- complementary medicines
- prescriptions (All)
- OTC (Most)
- complementary (some)
59
is the legal process used to restrict safe and effective use
Scheduling
60
The higher the # of the schedules, the _______ restricted
more restricted
61
pharmacy only medicine (large pack of paracetamol)
Schedule 2
62
pharmacist only medicine (proton pump inhibitors)
Schedule 3
63
prescription only medicine (blood pressure medications)
Schedule 4
64
controlled drug (strong analgesics)
Schedule 8
65
Generic medicines contain ________________ as the existing medicine, and they must be bioequivalent
the same active ingredient
66
refers to whether the generic medicine releases the active ingredient into the bloodstream at the same rate and to the same extent as the original medicine
bioequivalent
67
Australian Government program that benefits all Australians by making medicine more affordable
Pharmaceutical Benefits Scheme (PBS)
68
Components to inflammation
- heat
- redness
- swelling
- pain
- loss of function
69
how is inflammation triggered?
Inflammatory mediators (e.g.; prostaglandins and cytokines) are released from damaged tissues and immune cells and can stimulate nociceptors (“pain receptors”) directly
70
process where reduce the activation threshold of nociceptors so that the stimulation required to cause activation is less
primary sensitization
71
What are examples of mediators?
histamine, prostaglandin, leukotrienes, cytokines
72
What to analgesic medications help?
Pain!
73
What do anti-inflammatory medications reduce?
- swelling
- heat
- redness
74
Where do local anesthetics and NSAIDs work?
nerve endings and primary afferent nerve
75
Where do local anesthetics and alpha 2 agonists work?
dorsal root ganglion
76
Where do opioids, ketamine, gabapentinoids work?
dorsal horn
77
What tracts are analgesic medications work on?
ascending spinothalamic fibers
78
What are facilitators of pain signaling pathway?
- increase in substance P
- glutamate and excitatory amino acids
- serotonin
- increase in nerve growth factor
79
what inhibits the pain signaling pathway?
- descending anti-nociceptive pathways
- norepinephrine-serotonin, dopamine decrease
- increase in poi's
- GABA
- cannabinoids
80
pain that affects bones, joints, connective tissue, muscles
somatic (nociceptive pain)
81
a high threshold sensory receptor of the peripheral somatosensory nervous system that is capable of transfusing and encoding noxious stimuli
nociceptor
82
pain due to a stimulus that does not normally provoke pain
allodynia
83
Why are anti-inflammatory drugs used in virtually all branches of medicine?
This is because inflammation forms a significant component of many, if not most, of the diseases encountered in the clinic.
84
Despite diversity all the NSAIDs possess ____________ properties
analgesic, antipyretic and anti-inflammatory
85
how does the body create analgesic effect?
Decreased production of prostaglandin: less sensitisation of nociceptive nerve ending
86
How does the body create anti-inflammatory action?
Reduces vasodilation and, indirectly, oedema by decreasing prostaglandin E2 and prostacyclin synthesis.
87
How does the body create an antipyretic effect?
NSAIDspreventsthereleaseof prostaglandins by interleukin-1 in the CNS, where they elevate the hypothalamic set point for temperature control. Therefore preventing fever.
88
How can you inhibit synthesis of prostaglandins?
inhibit COX enzymes (COX1 and COX2)
89
- impaired gastric protection
- antiplatelet effects
- reduction in glomerular filtration rate
- reduction in renal flow
COX-1 inhibition
90
- anti-inflammatory action
- analgesis action
- reduction in glomerular filtration rate
- reduction in renal flow
COX-2 inhibition
91
indications for NSAID usage in clinic
- pain due to inflammation and tissue injury
- fever
- osteoarthritis
- acute gout
- rheumatoid arthritis
92
adverse effects of using NSAIDs
- nausea, diarrhea, headache
- dyspepsia, GI ulceration
- raised liver enzymes
- dizziness
- salt and fluid retention
- hypertension
93
paracetamol is a form of...?
acetaminophen
