Pharmacology Flashcards
1
Q
Define
One-compartment model of pharmacokinetics
A
Assumes the drug is evenly distributed thoughout the body and the rate of elimination (k) is constant
2
Q
Define
Two-comparment model of pharmacokinetics
A
Assumes a drug is taken up by different tissues and the volume of distribution between tissues is different
3
Q
In the context of comparment models, a drug is only eliminated through the __ comparment
A
Central
4
Q
Which compartment model best represents what happens in the body
A
Multi-comparment model
5
Q
Define
Open model
A
The drug is eliminated from the body through the central compartment
6
Q
Define
Closed model
A
The drug is recirculated in the body through entero-hepatic circulation
This is rare
7
Q
Define
Zero order kinetics
A
The rate at which {drug} changes is constant and independent of drug concentration
8
Q
Define
First order kinetics
A
The rate of drug elimination is proportional to the {drug}
9
Q
List 4 factors influencing the movement of drugs in the body
A
- Physiochemical properties
- Location/target tissue
- Mechanism of transport
- pH & ion trapping
Remember, drugs cross membranes in their non-ionized form
10
Q
Define
Pharmacokinetics
A
What the body does to the drug
11
Q
Define
Pharmacodynamics
A
What the drug does to the body
12
Q
What are the 4 phases of drug pharmacokinetics
Think of the acryonym
A
- Absorption
- Distribution
- Metabolism
- Excretion
ADME
13
Q
List 3 routes of parenteral drug administration
A
- Intravenous
- Intramuscular
- Subcutaneous
14
Q
Define
Absorption
A
The passage of the drug from the site of administration to the blood stream
15
Q
Explain
First pass effect
A
Describes how a % of drug is lost as it goes through the liver and portal vein to enter systemic circulation
16
Q
How can you avoid the % of drug loss associated with the first pass effect
A
By administering the drug rectally or sublingually
17
Q
Which protein does a drug bind to in the blood?
A
Albumin
18
Q
Define
Volume of distribution (Vd)
And what is it directly related to?
A
The amount of tissue to which a drug distributes
Plasma concentration
19
Q
What does a Vd of >2kg/kg indicate?
A
That drug is accumulationg in a specific site or fatty tissue
20
Q
Where does biotransformation primarily occur?
A
The liver
21
Q
Where does excretion primarily occur?
A
The kidney
22
Q
Describe the components of
Phase I reactions
Part of biotransformation
A
Includes hydrolysis, reduction and oxidation
23
Q
Describe the components of
Phase II reactions
Part of biotransformation
A
Conjugation (includes acetylation, conjugation to amino acids, and glucuronidation)
24
Q
What is C0?
In the context of volume of distribution
A
The drug plasma concentration after equilibrium but before elimination
25
Define antimicrobial
Agent that kills microbes or inhibits their growth without damaging the host
26
Define antibiotic
Microbial products that kill or inhibit other micro-organisms
27
Define antibacterial
Synthetic agents with activity against bacteria
28
__ do not cause AMR
Antimicrobials
29
Define inherent resistance
| Provide an example
Lack of bacterial activity due to inherent phenotype (i.e., lack of appropriate target)
| Mycoplasms are resistant to beta-lactams because they do not have a cell
30
Define chromosomal resistance
| What type of transmission is this?
Mutations in the organism that confer resistance
| Vertical transmission
31
Define transferable resistance
| What type of transmission is this?
Resistance genes aquired through mobile genetic elements
| Vertical and horizontal transmission
32
List 3 AMR organisms of concern
1. Methicillin resistant staphylococci
2. Multidrug resistant cocci
3. Multidrug resistant enterbacteriacae
33
Define a nosocomial infection
An infection aquired through health care
34
List 3 risk factors for nosocomial AMR
| (aquired through healthcare)
1. Very young or old animals
2. Immunocomprimised patients
3. Broad spectrum antibacterial use
35
What are the 3 most important drivers for antimircobial use in practice?
1. Vet prescribing behaviours
2. Interactions with clients
3. Practice norms
36
List 5 conditions in which system antimicrobials are not needed as a first line treatment
1. Acute vomiting or diarrhoea
2. Otitis externa
3. Acute conjunctivitis
4. Cat bite abscesses
5. Feline lower urinary tract disease
37
List the 7 key concepts for responsible antimicrobial use
1. Know there is a bacterial infection
2. Do you need systemic AM's?
3. Is treatment required immediately?
4. Choose an appropriate AM
5. Use the correct dose
6. Choose the correct treatment duration
7. Improve compliance
38
List 6 factors affecting PK/PD models
1. Poor bioavailability
2. Hypovolumic shock
3. Renal and/or liver disease
4. Increased MIC
5. Biofilms
6. Pus, debris or foregin materials
39
List 3 factors that may necessitate the need for higher doses of hydrophilic drugs to ensure theraputic concentrations
1. Fluid retention
2. IV fluids
3. Increases renal clearance
| Means theres an alt fluid balance, drugs may be diluted or excreted fast
40
__ drugs penetrate tissues more effectively
Lipophilic
41
List one antimicrobial for each category of tissue penetration: excellent, good and poor
Excellent: Doxycycline, metronidazole
Good: Tetracyclines, macrolides
Poor: Penicillins, cephalosporins
42
List a concentration dependent drug
Most fluoroquinolones
43
How is the efficacy of concentration dependent drugs measured?
The ratio between the peak concentration and the MIC
44
How would you dose a concentration dependent drug?
Give the maximum dose every 24 hours
45
List a time dependent drug
Penicillin
46
How do you measure the efficacy of a time dependent drug?
Time above MIC
47
How would you dose a time dependent drug?
Give the appropriate dose every 8-12 hours
48
List one advantage for both bactericidal and bacteriostatic drugs
Bactericidal: more effective in immunocomprimised patients
Bacteriostatic: release less toxins
49
List 3 bacteriostatic drugs
1. Tetracycline
2. Sulphonamides
3. Lincosamides
50
List 3 bactericidal drugs
1. Penicillin
2. Cephalosporin
3. Fluoroquinolones
51
Which dog breed have a specific risk for ADRs to sulphonamides?
Dobermans
52
List 3 drugs that are excreted hepatically
1. Fluoroquinolones
2. Doxycycline
3. Rifampicin
53
List 3 drugs that are excreted both hepatically and renally
1. Tetracyclines
2. Lincosamides
3. Fluoroquinolones
54
List 3 drugs are excreted renally
1. Penicillins
2. Cephalosporines
3. Trimethoprim-sulphonamides
55
List 3 ADRs you can see with tetracyclines
1. Injection site reactions
2. Hepatic enzyme induction
3. Oesophageal ulceration
56
# List a pathogen that is most likely causes this infection
Pyoderma
Staphylococci
57
# List a pathogen that is most likely causes this infection
Otitis externa
Staphylococci or pseudomonas
58
# List a pathogen that is most likely causes this infection
Otitis media
Staphylococci or pseudomonas
59
# List a pathogen that is most likely causes this infection
Cystitis
E. coli
60
# List a pathogen that is most likely causes this infection
Prostatitis
E. coli
61
# List a pathogen that is most likely causes this infection
Gingivites & periodontitis
Spirochetes
62
# List a pathogen that is most likely causes this infection
Cholangio-hepatitis
E. coli
63
# List a pathogen that is most likely causes this infection
Anal sacs
E. coli or enterococcus
64
# List a pathogen that is most likely causes this infection
Conjunctivitis in cats
Chlamydophilia felis
65
# List a pathogen that is most likely causes this infection
Conjunctivitis in dogs
Staphylococci or streptococci
66
# List a pathogen that is most likely causes this infection
Upper respiratory tract infection
Bordatella
67
# List a pathogen that is most likely causes this infection
Pneumonia pyothorax in dogs
Gram negative aerobes
68
# List a pathogen that is most likely causes this infection
Pneumonia pyothorax in cats
Pasturella
69
# List a pathogen that is most likely causes this infection
Mastitis
E. coli
70
# List a pathogen that is most likely causes this infection
Septicaemia
Staphylococci or e.coli
71
# Define
Catecholamine
| Provide 3 examples
A monoamine transmitter derived from the amino acid tyrosine
| Adrenaline, noradrenaline and dopamine
72
# Define
Chronotropic
An agent that increases heart rate
73
# Define
Dromotropic
An agent that affects conduction speed by changing the delay in the AV node
74
# Define
Positive dromotrophy
| Provide an example of something that does this
Something that increases conduction velocity
| Adrenaline
75
# Define
Negative dromotrophy
| Provide an example of something that does this
Something that decreases conduction velocity
| Vagal stimulation
76
# Define
Inotropic
An agent that increases the force of contraction
77
# Define
Sympathomimetic drugs
Drugs with similar actions to the post-ganglionic fibers of the CNS
| Also known as adrenergics (they resemble adrenaline)
78
# Define
Sympatholytic drugs
Drugs that oppose the actions of the post-ganglionic fibers of the SNS
| Also known as anti-adrenergics or sympathetic antagonists
79
# Define
Parasympathomimetic drugs
Drugs that stimulate post-synaptic muscarinic receptors
| Also known as cholinergics (they resemble acetlycholine)
80
# Define
Parasympatholytic drugs
Drugs that oppose the actions of the PNS at the muscarinic receptors
| Also known as anti-cholinergics
## Footnote
They do this by blocking the actions of acetylcholine
81
# Define
Adrenergic direct acting agonists/agonists
Agents that can act at one or more post-synaptic adrenergic receptors
82
# Define
Adrenergic indirect acting agonists
Agents that increase the release of NE or inhibit its uptake
83
What is the action of mixed acting sympathomimetics
They indirectly release noradrenaline and directly activate receptors
84
What are the 2 main neurotransmitters of the ANS
1. Acetylecholine (parasympathetic)
2. Noradrenaline (sympathetic)
85
All pre-synaptic autonomic fibers and somatic motor fibers are __
Cholinergic (stimulated by acteylcholine)
86
What is the function of dopamine as a neurotransmitter in the ANS
It is a modulatory transmitter in some ganglia, the enteric NS and renal blood vessels
87
Noradrenaline has a higher affinty for __
Alpha receptors
88
Adrenaline has a higher affinity for __
Beta receptors
89
What is the final product in most sympathetic post-synpatic neurons
Noradrenaline
90
List 5 key features of neurotransmitter function that provide targets for drugs
1. Synthesis
2. Storage
3. Release
4. Binding to receptor
5. Termination
91
How does adrenaline treat anaphylaxis?
| I.e., what receptors does it act on?
Alpha-1: increases vasoconstriction and peripheral vascular resistance
Beta-1: increases iontropy and chronotropy
Beta-2: increases bronchodilation and decreases release of inflammatory mediators
92
What is the cellular response following the activation of M1, M3 and M5 muscarinic receptors?
Activation of PLC (phospholipase C)
93
What is the cellular response following the activation of M2 and M4 muscarinic receptors?
Deactivation of AC (adenylate cyclate)
94
# List the class and action of the following PNS drug
Acetylcholine
Choline ester (direct muscarinic agonist)
Negative chronotropy, inotropy and dromotropy in the cardiovascular system
95
# List the class and action of the following PNS drug
Methacholine
Choline ester (direct muscarinic agonist)
Treats bronchial reactivity
96
# List the class and action of the following PNS drug
Bethanechol
Choline ester (direct muscarinic agonist)
Induces urination (minimal cardiac effects)
97
# List the class and action of the following PNS drug
Carbachol
Choline ester (significant nicotinic action)
Induces gastric motility, urination and miosis
98
# List the class and action of the following PNS drug
Pilocarpine
Alkaloids (direct muscarinic agonist)
Induces miosis (used to treat glaucoma)
99
Which class of PNS drugs do anticholinesterases belong to?
Indirect muscarinic agonists
100
Describe the action of anticholinesterases
They inhibit acetylcholinesterase to increase acetylcholine activity at the post synaptic membrane
101
List the 2 categories of anticholinesterases
1. Reversible
2. Irreversible
102
List 6 toxic effects of anticholinesterases
| SLUDGE
1. Salivation
2. Lacrimation
3. Urination
4. Defecation
5. GI distress
6. Emesis
| Also muscle tremors, miosis and collapse
103
How can anticholinesterases reverse a neuromuscular block?
Anticholinesterases increase the amount of Ach at the NMJ, which can out compete the competitive antagonists for the Ach receptors
104
# List the class and action of the following PNS drug
Edrophonium chloride
Anticholinesterase
Used in the diagnosis of myasthenia gravis, and reverses non-depolarizing muscle relaxants
105
# List the class and action of the following PNS drug
Neostigmine
Anticholinesterase
Treatment of myasthenia gravis, and reverses non-depolarizing muscle relaxants
106
# List the class and action of the following PNS drug
Pyridostigmine
Anticholinesterase
Treatment of myasthenia gravis
107
# List the class and action of the following PNS drug
Atropine
Anticholingeric (natural muscarinic antagonist)
Increases heart rate, used with anticholinesterases to prevent side effects from reversing neurmuscular blockade, and induces mydriasis
108
List 3 adverse effects of atropine
1. Tachycardia
2. Urinary retention
3. Decreases gastric secretion
| Can be a problem with CNS stimulation in the horse
109
# List the class and action of the following PNS drug
Scopolamine
Anticholinergic (natural muscarinic antagonist)
Antispasmadic and antiemetic
110
# List the class and action of the following PNS drug
Glycopirrolate
Anticholinesterase (synthetic muscarinic antagonist)
Used to prevent and treat bradycarida (has much milder effects than atropine)
111
# List the class and action of the following PNS drug
Ipratopium bromide
Anticholinergic
Bronchodilation in horses
112
# List the class and action of the following PNS drug
Cyclopentolate
Anticholinergic
Induces mydriasis (cyclopelgic)
113
# List the class and action of the following PNS drug
Tropicamide
Anticholinergic
Induces mydriasis (NOT cyclopelgic)
114
How is norepinephrine inactivated at the synaptic junction?
By reuptake into the pre-synaptic cell
115
What is the precursor of norepinephrine?
| List the 3
Tyrosine -> dopa -> dopamine
116
Adrenoreceptors and muscarinic receptors are __ receptors
G-protein coupled
117
# Where is this receptor located
Alpha-1
Vascular smooth muscle
118
# Where is this receptor located
Alpha-2
CNS
119
# Where is this receptor located
Beta-1
Heart
120
# Where is this receptor located
Beta-2
Smooth muscle
121
# Where is this receptor located
Beta-3
Adipose tissue
122
# Where is this receptor located
M1
CNS and stomach
123
# Where is this receptor located
M2
Heart
124
# Where is this receptor located
M3
Glands and smooth muscle
125
# Where is this receptor located
M4
CNS and heart
126
# Where is this receptor located
M5
CNS
127
List 3 naturally occuring sympathomimetics
| Aka SNS agonists
1. Adrenaline
2. Noradrenaline
3. Dopamine
128
# List the class and action of the following SNS drug
Adrenaline
SNS agonist
Acts on alpha and beta receptors to increase HR, force of contraction and vasoconstriction (used for cardiac arrest and anaphylaxis)
129
# List the class and action of the following SNS drug
Noradrenaline
SNS agonist
Primarily acts on alpha receptors to induce vasoconstriction, also beta receptors to increase contractility
130
# List the class and action of the following SNS drug
Dopamine
SNS agonist
At low doses, acts on dopa receptors to cause vasodilation
At medium doses, acts on beta receptors to increase strength and rate of heart
At high doses, acts on alpha receptors to cause vasoconstriction
131
# List the class and action of the following SNS drug
Phenylephrine
Alpha-1 agonist
Induces mydriasis and increases arterial pressure
132
What are the general effects of alpha-1 agonists
They induce vasoconstriction and increase the force of contraction
133
What are the general effects of alpha-2 agonists
They increase systemic vascular resistance and cause vasoconstriction
| Also used for sedative and analgesic properties
134
What are the general effects of beta-1 agonists
They increase heart rate and the force of contraction
135
# List the class and action of the following SNS drug
Dobutamine
Beta-1 agonist
Used in equine anaesthesia to maintain arterial pressure, and small animal surgery to increase heart strength
136
# List the class and action of the following SNS drug
Clenbuterol
Beta-2 agonist
Used for the treatment of recurrent airway obstruction in horses (bronchodilation and vasodilation)
137
# List the class and action of the following SNS drug
Terbutaline
Beta-2 agonist
Used for bronchodilation and to treat hyperkalemia
138
# List the class and action of the following SNS drug
Salbutamol
Beta-2 agonist
Used in equine anaesthesia to treat hypoxaemia
139
# List the class and action of the following SNS drug
Isoxuprine
Beta-2 agonist
Induces vasodilation and decreases uterine contraction to delay parturition
140
What are the general effects of beta-2 agonists
Bronchodilation and uterine relaxation
141
# List the class and action of the following SNS drug
Prazosin
Alpha-1 antagonist
Induces vasodilation and promotes urine output
142
What is the general effect of alpha-2 antagonists
They reverse sedation induced by alpha-2 agonists
143
# List the class and action of the following SNS drug
Phenoxybenzamine
Non-selective alpha antagonist
Long-acting alpha-1 adrenoreceptor blocker
144
# List the class and action of the following SNS drug
Phentolamine
Non-selective alpha antagonist
Short-acting alpha-1 adrenoreceptor blocker
