Pharmacodynamics Flashcards
1
Q
Partial Agonists:
can never produce a maximal response at a receptor
A
True
2
Q
Partial Agonists:
Cause a parallel shift in the semilogarithmic dose response curve
A
False
3
Q
Partial Agonists:
Bind irreversibly to receptor sites
A
False
4
Q
Partial Agonists:
Generally have a lower affinity for the receptor than the agonist
A
False
5
Q
Partial Agonists:
If a partial agonist has the same affinity for a receptor as the agonist, it’s equilibrium constant will be the same
A
True
6
Q
The following are example of hepatic enzyme inducers:
Ranitadine
A
False
7
Q
The following are example of hepatic enzyme inducers:
Erythromycin
A
False
8
Q
The following are example of hepatic enzyme inducers:
Phenytoin
A
True
9
Q
The following are example of hepatic enzyme inducers:
Amiodarone
A
False
10
Q
The following are example of hepatic enzyme inducers:
Cigarette smoking
A
True
11
Q
The following are examples of hepatic enzyme inhibitors:
Amiodarone
A
True
12
Q
The following are examples of hepatic enzyme inhibitors:
Carbemazepine
A
False
13
Q
The following are examples of hepatic enzyme inhibitors:
Metronidazole
A
True
14
Q
The following are examples of hepatic enzyme inhibitors:
Fludrocortisone
A
False
15
Q
The following are examples of hepatic enzyme inhibitors:
Ceftriaxone
A
False
16
Q
Concerning drug dose response and response:
A plot of % response against drug concentration gives a sigmoid shape
A
False
17
Q
Concerning drug dose response and response:
Antagonists must have a higher receptor affinity than agonists
A
False
18
Q
Concerning drug dose response and response:
Intrinsic activity determines maximal response
A
True
19
Q
Concerning drug dose response and response:
Maximal response occurs only when all the receptor sites are occupied
A
False
20
Q
Concerning drug dose response and response:
Partial agonism implies low receptor affinity
A
False
21
Q
The efficacy (or intrinsic activity) of a drug: Is greater for drug A if A is effective in a dose of 100 micrograms than for drug B if B is effective in a dose of 100 milligrams
A
False
22
Q
The efficacy (or intrinsic activity) of a drug: Is a measure of its theraputic index
A
False
23
Q
The efficacy (or intrinsic activity) of a drug: Is a measure of the amount of a drug required to produce a given affect
A
False
24
Q
The efficacy (or intrinsic activity) of a drug: Describes the ability of a drug to produce its therapeutic effect
A
True
25
```
The efficacy (or intrinsic activity) of a drug:
Is a measure of the bioavailability of a drug
```
False
26
Genetic polymorphisms of drug metabolism:
| Exhibit inter-ethnic differences
True
27
Genetic polymorphisms of drug metabolism:
| Are not associated with adverse effects
False
28
Genetic polymorphisms of drug metabolism:
| Are dependent on the pharmacological actions of the drug
False
29
Genetic polymorphisms of drug metabolism:
| Are due to altered gene expression
True
30
Genetic polymorphisms of drug metabolism:
| Are not clinically important for drugs eliminated by the kidney
True
31
Metabolism of the following drugs are affected by the acetylator status of the individual:
Hydralazine
True
32
Metabolism of the following drugs are affected by the acetylator status of the individual:
isoniazid
True
33
Metabolism of the following drugs are affected by the acetylator status of the individual:
Propranolol
False
34
Metabolism of the following drugs are affected by the acetylator status of the individual:
Amiodarone
False
35
Metabolism of the following drugs are affected by the acetylator status of the individual:
Digoxin
False
36
Regarding log-dose response curves:
| Potency is the ability of a drug to produce maximal response
False
37
Regarding log-dose response curves:
| A partial agonist binds to the receptor with a lower affinity than the agonist
False
38
Regarding log-dose response curves:
In the presence of a competitive antagonist the log dose-response curve for an agonist shows a parallel shift to the right
True
39
Regarding log-dose response curves:
In the presence of a non-competitive antagonist the log dose-response curve for an agonist shows a parallel shift to the left
True
40
The following interactions are antagonistic:
| Naloxone and dextropropoxphe
True
41
The following interactions are antagonistic:
| Acetylcysteine and paracetamol
True
42
The following interactions are antagonistic:
| Atenolol and salbutamol
True
43
The following interactions are antagonistic:
| Protamine and warfarin
False
44
The following interactions are antagonistic:
| Tranexamic acid and streptokinase
True
45
Non-competitive agonists:
| Move the log dose-response curve for a drug in the right in a non-parallel manner
True
46
Non-competitive agonists:
| Reduce the gradient of the log dose-response curve
True
47
Non-competitive agonists:
| Have an effect unrelated to the agonist plasma concentration
False
48
Non-competitive agonists:
| Prevent maximum agonist response
True
49
Non-competitive agonists:
| Display surmountability
False
50
The following drugs act via enzyme inhibition:
| Allopurinol
True
51
The following drugs act via enzyme inhibition:
| Physostigmine
True
52
The following drugs act via enzyme inhibition:
| Indomethacin
True
53
The following drugs act via enzyme inhibition:
| Meptazinol
False
54
The following drugs act via enzyme inhibition:
| Enoximone
True
55
An hereditary enzyme abnormality may lead to altered metabolism of:
Propofol
False
56
An hereditary enzyme abnormality may lead to altered metabolism of:
Isoniazid
True
57
An hereditary enzyme abnormality may lead to altered metabolism of:
Thiopentone
False
58
An hereditary enzyme abnormality may lead to altered metabolism of:
Suxamethonium
True
59
An hereditary enzyme abnormality may lead to altered metabolism of:
Atracurium
False
60
Competitive antagonists:
| Shift the log dose-response curve right
True
61
Competitive antagonists:
| Can bind to a different receptor site than the agonist
False
62
Competitive antagonists:
| At the neuromuscular junction, weak antagonists tend to have a faster onset
True
63
Competitive antagonists:
| Shift the log dose-response down
False
64
Competitive antagonists:
| Are compared with one another by the degree of reduction in maximal response
False
65
Regarding partial agonists:
| If an agonist has an intrinsic activity of <1, it is termed a partial agonist
True
66
Regarding partial agonists:
| If given in very large doses partial agonists may achieve a full response
False
67
Regarding partial agonists:
| If given in combination with a full agonist, they can act as an antagonist
True
68
Regarding partial agonists:
| If given in combination with a full agonist, they can act as an agonist
True
69
Regarding partial agonists:
| If given alone, partial agonists can act as agonists or antagonists
False
70
Regarding drug-receptor interactions:
| Affinity refers to how well a drug binds to its receptor
True
71
Regarding drug-receptor interactions:
| Intrinsic activity refers to the magnitude of effect once a drug has bound to receptor
True
72
Regarding drug-receptor interactions:
| A drug with high affinity will produce a large response
False
73
Regarding drug-receptor interactions:
| Partial agonists have a low receptor affinity
False
74
Regarding drug-receptor interactions:
| Antagonists will have high receptor affinity
True
75
A drug that is 98% protein bound:
| Will double its free drug concentration if protein binding is decreased to 96%
True
76
A drug that is 98% protein bound:
| Will show 2% increase in free drug concentration if protein binding falls 2%
False
77
A drug that is 98% protein bound:
| must have a pKa >7.4
False
78
A drug that is 98% protein bound:
| might be diazepam
True
79
A drug that is 98% protein bound:
| might be midazolam
True
80
The following are examples of pharmacokinetic drug interactions:
Lithium and thiazide diuretics
True
81
The following are examples of pharmacokinetic drug interactions:
Digoxin and amiodarone
True
82
The following are examples of pharmacokinetic drug interactions:
Phenytoin and cimetidine
True
83
The following are examples of pharmacokinetic drug interactions:
Beta blokers and verapamil
False
84
The following are examples of pharmacokinetic drug interactions:
Ethanol and diazepam
False
85
The following drugs exhibit tachyphylaxis:
| GTN
True
86
The following drugs exhibit tachyphylaxis:
| Ephidrine
True
87
The following drugs exhibit tachyphylaxis:
| Succinylcholine
False
88
The following drugs exhibit tachyphylaxis:
| Trimetaphan
True
89
The following drugs exhibit tachyphylaxis:
| Hydralazine
False
90
The rate of diffusion of a drug across a membrane is dependent upon:
The drug concentration gradient across the membrane
True
91
The rate of diffusion of a drug across a membrane is dependent upon:
Fick's law
True
92
The rate of diffusion of a drug across a membrane is dependent upon:
Dalton's law
False
93
The rate of diffusion of a drug across a membrane is dependent upon:
The surface area of the membrane
True
94
The rate of diffusion of a drug across a membrane is dependent upon:
The degree of ionisation of the drug
True
95
The following are examples of physiological antagonism
| Morphine and naloxone
False
96
The following are examples of physiological antagonism
| Fentanyl and doxapram
True
97
The following are examples of physiological antagonism
| Morphine and pentazocine
False
98
The following are examples of physiological antagonism
| Ritodrine and syntocinon
True
99
The following are examples of physiological antagonism
| Frusemide and amiloride
True
100
Partial agonists:
| Act as both agonists and antagonists
True. Partial agonists act as agonists in isolation, but can act antagonistically when given in combination with a full agonist.
101
Partial agonists:
| Have similar intrinsic activity to full agonists
False. Full agonists have an intrinsic activity of 1, whereas a partial agonists have an intrinsic activity of <1.
102
Partial agonists:
| Include buprenorphine
True
103
Partial agonists:
| Include pentazocine
False. Pentazocine is a mixed agonist-antagonist.
104
Partial agonists:
| Include clozapine
True. Clozapine is a partial agonist at D2 receptors.
105
Antagonists:
| Have intrinsic activity, but lack affinity
False. They have affinity, but an intrinsic activity of zero.
106
Antagonists:
| Competitive antagonism reduces Emax
False. Maximum efficacy (Emax) remains the same, but the dose-response curve is shifted to the right. Non-competitive antagonism reduces Emax
107
Antagonists:
| Competitive antagonists bind to a site distal to the receptor involved
False. Competitive antagonists compete for a receptor with agonists. Non-competitive antagonists bind to a distal site, and induce a change at the receptor.
108
Antagonists:
| Non-competitive antagonism is overcome by increasing agonist dose
False. This is competetive antagonism.
109
Antagonists:
| May also act as agonists
True. Mixed agonists-antagonists can act as agonists at some receptors and antagonists at others e.g. pentazocine.
110
Regarding the log dose-response curve:
| The ED50 is the drug concentration that induces a response halfway between zero and maximum
False. ED50 refers to the dose of drug - this question defines the Effective Concentration 50.
111
Regarding the log dose-response curve:
| Therapeutic index = Lethal Dose 50 / Effective Dose 50
True
112
Regarding the log dose-response curve:
| Drugs with a narrow therapeutic window do not require monitoring
False. Drugs with a narrow therapeutic window often require close monitoring as the risk of reaching toxic levels is greater.
113
Regarding the log dose-response curve:
| It is shifted to the left with the addition of a competitive antagonist
False. The curve is shifted to the right as a higher dose of agaonist is required to produce an equivalent response.
114
Regarding the log dose-response curve:
| Potency is represented by the height of the curve
False. It is represented by the position of ED50, much like the position of P50 on the oxy-Hb dissociation curve.
115
Receptors and 2nd messengers:
| G-protein receptors have alpha, beta and delta subunits
False. G-proteins consist of alpha, beta and gamma subunits.
116
Receptors and 2nd messengers:
| Insulin receptors are G-protein coupled
False. The Insulin receptor utilises tyrosine kinase.
117
Receptors and 2nd messengers:
| Opioid receptors are G-protein coupled
True
118
Receptors and 2nd messengers:
| cAMP is a hydrophobic molecule
False. It is hydrophilic.
119
Receptors and 2nd messengers:
| Nitric oxide acts via cAMP
False. It acts via cGMP.
120
The following antagonists have agonist properties:
| Ranitidine
False. It is an H2-receptor antagonist.
121
The following antagonists have agonist properties:
| Prazosin
False. It is a selective alpha1-adrenoreceptor blocker.
122
The following antagonists have agonist properties:
| Pindolol
True. It is a non-selective Beta-blocker with partial beta-agonist activity. It also has partial agonist / antagonist activity at the 5-HT1A receptor.
123
The following antagonists have agonist properties:
| Naltrexone
False. It is an opioid receptor antagonist.
124
The following antagonists have agonist properties:
| Xameterol
True. It is a mixed beta-agonist/antagonist.
125
Regarding negative exponential processes:
| The rate of decay varies with time
True. In an exponential process the rate of change of a variable is proportional to the magnitude of the variable at that moment in time. In a negative exponential process, the rate of decay is decreasing with increasing time.
126
Regarding negative exponential processes:
| The time constant is longer than the half-life
True. An exponential process is said to be complete after 3 time constants, as opposed to 5 half-lives.
127
Regarding negative exponential processes:
| The time constant is the natural logarithm of the half-life
False. The time constant is the reciprocal of the rate constant.
128
Regarding negative exponential processes:
| Is converted into a straight line by a semi-log plot
True. This is true of other exponential processes also. It allows for easier interpretation.
129
Regarding negative exponential processes:
| The time constant is the time for the process to complete if the rate continued at its initial speed
True. It can also be defined as the time taken for an exponential process to fall to 37% or 1/e of its previous value.
130
Receptors:
| Drug affinity depends on the attraction between receptors and drugs
True. Affinity is the ability of a ligand to bind to a specific receptor.
131
Receptors:
| Thyroid hormones bind to cell surface receptors
False. They bind to intracellular receptors.
132
Receptors:
| Acetylcholine receptors have 2 alpha and 2 beta subunits
False. The adult acetylcholine receptor has 2 alpha subunits (to which acetylcholine binds), a beta subunit, a delta subunit and an episilon subunit (this is replaced by a gamma subunit in the foetus).
133
Receptors:
| Midazolam acts at GABAb receptors
False. It acts at GABAa receptors.
134
Receptors:
| Nicotinic hormones bind to intracellular receptors
False. Nicotinic receptors are type 1 receptors according to Urquhart's calssification - membrane bound ligand gated ion channels.
135
Regarding chemical bond strength:
| Van der Waals > Hydrogen > Ionic > Covalent
False
136
Regarding chemical bond strength:
| Covalent > Ionic > Hydrogen > Van der Waals
False
137
Regarding chemical bond strength:
| Covalent > Hydrogen > Ionic > Van der Waals
False
138
Regarding chemical bond strength:
| Ionic > Covalent > Hydrogen > Van der Waals
True
139
Regarding chemical bond strength:
| Van der Waals > Hydrogen > Covalent > Ionic
False
140
The following processes are mediated by cAMP:
| Decreased heart rate
True. Both increases and decreases in heart rate are mediated via cAMP. Beta1-adrenoreceptors are G-protein coupled - their stimulation causes increased cAMP and subsequent tachycardia. Muscarinic M2 receptors are Gi type g-protein coupled receptors and when stimulated decrease cAMP and reduce heart rate via opening of potassium channels
141
The following processes are mediated by cAMP:
| Liver carbohydrate metabolism
True. Beta2-adrenoreceptors are G-protein coupled, and their stimulation causes increased cAMP and subsequent glycogenolysis (also increases insulin and glucagon secretion).
142
The following processes are mediated by cAMP:
| Increased contractility
True. Beta1-adrenoreceptors are G-protein coupled, and their stimulation causes increased cAMP and subsequent increase in contractility.
143
The following processes are mediated by cAMP:
| Triglyceride breakdown
True. Beta2-adrenoreceptors are G-protein coupled, and their stimulation causes increased cAMP and subsequent lipolysis (also increases insulin and glucagon secretion). Beta 3-adrenoreceptors are also G-protein coupled and increase cAMP - they help regulation lipid metabolism.
144
The following processes are mediated by cAMP:
| Smooth muscle relaxation
True. Beta2-adrenoreceptors are G-protein coupled, and their stimulation causes increased cAMP and subsequent smooth muscle relaxation.
145
Which of the following may alter drug response:
| Tachyphylaxis
True. Tachyphylaxis is defined as a decreased response following a single administration of a drug.
146
Which of the following may alter drug response:
| Changes in receptor number
True. Whether this affects drug response depends on the degree of change in receptor number, and whether the drug response involves spare receptors (i.e. a full response is obtained despite some receptors not being occupied).
147
Which of the following may alter drug response:
| Hypersensitivity reactions
True
148
Which of the following may alter drug response:
| Idiosyncratic drug responses
True. Such reactions are not related to known pharmacological properties of a drug (i.e. not a common side effect, they are dose independent). They include anaphylaxis and anaphylactoid reactions.
149
Which of the following may alter drug response:
| Tolerance
True. Tolerance is the decreased responsiveness following repeated drug adminsitration.
