Pharmacodynamics Flashcards by Lydia Osborne | Brainscape

Q

Partial Agonists:

can never produce a maximal response at a receptor

A

True

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Q

Partial Agonists:

Cause a parallel shift in the semilogarithmic dose response curve

A

False

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Q

Partial Agonists:

Bind irreversibly to receptor sites

A

False

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Q

Partial Agonists:

Generally have a lower affinity for the receptor than the agonist

A

False

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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

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Q

The following are example of hepatic enzyme inducers:

Ranitadine

A

False

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Q

The following are example of hepatic enzyme inducers:

Erythromycin

A

False

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Q

The following are example of hepatic enzyme inducers:

Phenytoin

A

True

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Q

The following are example of hepatic enzyme inducers:

Amiodarone

A

False

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Q

The following are example of hepatic enzyme inducers:

Cigarette smoking

A

True

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Q

The following are examples of hepatic enzyme inhibitors:

Amiodarone

A

True

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Q

The following are examples of hepatic enzyme inhibitors:

Carbemazepine

A

False

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Q

The following are examples of hepatic enzyme inhibitors:

Metronidazole

A

True

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Q

The following are examples of hepatic enzyme inhibitors:

Fludrocortisone

A

False

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Q

The following are examples of hepatic enzyme inhibitors:

Ceftriaxone

A

False

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Q

Concerning drug dose response and response:

A plot of % response against drug concentration gives a sigmoid shape

A

False

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Q

Concerning drug dose response and response:

Antagonists must have a higher receptor affinity than agonists

A

False

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Q

Concerning drug dose response and response:

Intrinsic activity determines maximal response

A

True

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Q

Concerning drug dose response and response:

Maximal response occurs only when all the receptor sites are occupied

A

False

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Q

Concerning drug dose response and response:

Partial agonism implies low receptor affinity

A

False

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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

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Q

The efficacy (or intrinsic activity) of a drug:
Is a measure of its theraputic index

A

False

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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

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Q

The efficacy (or intrinsic activity) of a drug:
Describes the ability of a drug to produce its therapeutic effect

A

True

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Q

The efficacy (or intrinsic activity) of a drug:
Is a measure of the bioavailability of a drug

A

False

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Q

Genetic polymorphisms of drug metabolism:

Exhibit inter-ethnic differences

A

True

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Q

Genetic polymorphisms of drug metabolism:

Are not associated with adverse effects

A

False

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Q

Genetic polymorphisms of drug metabolism:

Are dependent on the pharmacological actions of the drug

A

False

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Q

Genetic polymorphisms of drug metabolism:

Are due to altered gene expression

A

True

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Q

Genetic polymorphisms of drug metabolism:

Are not clinically important for drugs eliminated by the kidney

A

True

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Q

Metabolism of the following drugs are affected by the acetylator status of the individual:
Hydralazine

A

True

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Q

Metabolism of the following drugs are affected by the acetylator status of the individual:
isoniazid

A

True

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Q

Metabolism of the following drugs are affected by the acetylator status of the individual:
Propranolol

A

False

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Q

Metabolism of the following drugs are affected by the acetylator status of the individual:
Amiodarone

A

False

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Q

Metabolism of the following drugs are affected by the acetylator status of the individual:
Digoxin

A

False

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Q

Regarding log-dose response curves:

Potency is the ability of a drug to produce maximal response

A

False

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Q

Regarding log-dose response curves:

A partial agonist binds to the receptor with a lower affinity than the agonist

A

False

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Q

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

A

True

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Q

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

A

True

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Q

The following interactions are antagonistic:

Naloxone and dextropropoxphe

A

True

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Q

The following interactions are antagonistic:

Acetylcysteine and paracetamol

A

True

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Q

The following interactions are antagonistic:

Atenolol and salbutamol

A

True

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Q

The following interactions are antagonistic:

Protamine and warfarin

A

False

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Q

The following interactions are antagonistic:

Tranexamic acid and streptokinase

A

True

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Q

Non-competitive agonists:

Move the log dose-response curve for a drug in the right in a non-parallel manner

A

True

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Q

Non-competitive agonists:

Reduce the gradient of the log dose-response curve

A

True

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Q

Non-competitive agonists:

Have an effect unrelated to the agonist plasma concentration

A

False

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Q

Non-competitive agonists:

Prevent maximum agonist response

A

True

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Q

Non-competitive agonists:

Display surmountability

A

False

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Q

The following drugs act via enzyme inhibition:

Allopurinol

A

True

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Q

The following drugs act via enzyme inhibition:

Physostigmine

A

True

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Q

The following drugs act via enzyme inhibition:

Indomethacin

A

True

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Q

The following drugs act via enzyme inhibition:

Meptazinol

A

False

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Q

The following drugs act via enzyme inhibition:

Enoximone

A

True

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Q

An hereditary enzyme abnormality may lead to altered metabolism of:
Propofol

A

False

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Q

An hereditary enzyme abnormality may lead to altered metabolism of:
Isoniazid

A

True

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Q

An hereditary enzyme abnormality may lead to altered metabolism of:
Thiopentone

A

False

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Q

An hereditary enzyme abnormality may lead to altered metabolism of:
Suxamethonium

A

True

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Q

An hereditary enzyme abnormality may lead to altered metabolism of:
Atracurium

A

False

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Q

Competitive antagonists:

Shift the log dose-response curve right

A

True

Q

Competitive antagonists:

Can bind to a different receptor site than the agonist

A

False

Q

Competitive antagonists:

At the neuromuscular junction, weak antagonists tend to have a faster onset

A

True

Q

Competitive antagonists:

Shift the log dose-response down

A

False

Q

Competitive antagonists:

Are compared with one another by the degree of reduction in maximal response

A

False

Q

Regarding partial agonists:

If an agonist has an intrinsic activity of <1, it is termed a partial agonist

A

True

Q

Regarding partial agonists:

If given in very large doses partial agonists may achieve a full response

A

False

Q

Regarding partial agonists:

If given in combination with a full agonist, they can act as an antagonist

A

True

Q

Regarding partial agonists:

If given in combination with a full agonist, they can act as an agonist

A

True

Q

Regarding partial agonists:

If given alone, partial agonists can act as agonists or antagonists

A

False

Q

Regarding drug-receptor interactions:

Affinity refers to how well a drug binds to its receptor

A

True

Q

Regarding drug-receptor interactions:

Intrinsic activity refers to the magnitude of effect once a drug has bound to receptor

A

True

Q

Regarding drug-receptor interactions:

A drug with high affinity will produce a large response

A

False

Q

Regarding drug-receptor interactions:

Partial agonists have a low receptor affinity

A

False

Q

Regarding drug-receptor interactions:

Antagonists will have high receptor affinity

A

True

Q

A drug that is 98% protein bound:

Will double its free drug concentration if protein binding is decreased to 96%

A

True

Q

A drug that is 98% protein bound:

Will show 2% increase in free drug concentration if protein binding falls 2%

A

False

Q

A drug that is 98% protein bound:

must have a pKa >7.4

A

False

Q

A drug that is 98% protein bound:

might be diazepam

A

True

Q

A drug that is 98% protein bound:

might be midazolam

A

True

Q

The following are examples of pharmacokinetic drug interactions:
Lithium and thiazide diuretics

A

True

Q

The following are examples of pharmacokinetic drug interactions:
Digoxin and amiodarone

A

True

Q

The following are examples of pharmacokinetic drug interactions:
Phenytoin and cimetidine

A

True

Q

The following are examples of pharmacokinetic drug interactions:
Beta blokers and verapamil

A

False

Q

The following are examples of pharmacokinetic drug interactions:
Ethanol and diazepam

A

False

Q

The following drugs exhibit tachyphylaxis:

GTN

A

True

Q

The following drugs exhibit tachyphylaxis:

Ephidrine

A

True

Q

The following drugs exhibit tachyphylaxis:

Succinylcholine

A

False

Q

The following drugs exhibit tachyphylaxis:

Trimetaphan

A

True

Q

The following drugs exhibit tachyphylaxis:

Hydralazine

A

False

Q

The rate of diffusion of a drug across a membrane is dependent upon:
The drug concentration gradient across the membrane

A

True

Q

The rate of diffusion of a drug across a membrane is dependent upon:
Fick’s law

A

True

Q

The rate of diffusion of a drug across a membrane is dependent upon:
Dalton’s law

A

False

Q

The rate of diffusion of a drug across a membrane is dependent upon:
The surface area of the membrane

A

True

Q

The rate of diffusion of a drug across a membrane is dependent upon:
The degree of ionisation of the drug

A

True

Q

The following are examples of physiological antagonism

Morphine and naloxone

A

False

Q

The following are examples of physiological antagonism

Fentanyl and doxapram

A

True

Q

The following are examples of physiological antagonism

Morphine and pentazocine

A

False

Q

The following are examples of physiological antagonism

Ritodrine and syntocinon

A

True

Q

The following are examples of physiological antagonism

Frusemide and amiloride

A

True

Q

Partial agonists:

Act as both agonists and antagonists

A

True. Partial agonists act as agonists in isolation, but can act antagonistically when given in combination with a full agonist.

Q

Partial agonists:

Have similar intrinsic activity to full agonists

A

False. Full agonists have an intrinsic activity of 1, whereas a partial agonists have an intrinsic activity of <1.

Q

Partial agonists:

Include buprenorphine

A

True

Q

Partial agonists:

Include pentazocine

A

False. Pentazocine is a mixed agonist-antagonist.

Q

Partial agonists:

Include clozapine

A

True. Clozapine is a partial agonist at D2 receptors.

Q

Antagonists:

Have intrinsic activity, but lack affinity

A

False. They have affinity, but an intrinsic activity of zero.

Q

Antagonists:

Competitive antagonism reduces Emax

A

False. Maximum efficacy (Emax) remains the same, but the dose-response curve is shifted to the right. Non-competitive antagonism reduces Emax

Q

Antagonists:

Competitive antagonists bind to a site distal to the receptor involved

A

False. Competitive antagonists compete for a receptor with agonists. Non-competitive antagonists bind to a distal site, and induce a change at the receptor.

Q

Antagonists:

Non-competitive antagonism is overcome by increasing agonist dose

A

False. This is competetive antagonism.

Q

Antagonists:

May also act as agonists

A

True. Mixed agonists-antagonists can act as agonists at some receptors and antagonists at others e.g. pentazocine.

Q

Regarding the log dose-response curve:

The ED50 is the drug concentration that induces a response halfway between zero and maximum

A

False. ED50 refers to the dose of drug - this question defines the Effective Concentration 50.

Q

Regarding the log dose-response curve:

Therapeutic index = Lethal Dose 50 / Effective Dose 50

A

True

Q

Regarding the log dose-response curve:

Drugs with a narrow therapeutic window do not require monitoring

A

False. Drugs with a narrow therapeutic window often require close monitoring as the risk of reaching toxic levels is greater.

Q

Regarding the log dose-response curve:

It is shifted to the left with the addition of a competitive antagonist

A

False. The curve is shifted to the right as a higher dose of agaonist is required to produce an equivalent response.

Q

Regarding the log dose-response curve:

Potency is represented by the height of the curve

A

False. It is represented by the position of ED50, much like the position of P50 on the oxy-Hb dissociation curve.

Q

Receptors and 2nd messengers:

G-protein receptors have alpha, beta and delta subunits

A

False. G-proteins consist of alpha, beta and gamma subunits.

Q

Receptors and 2nd messengers:

Insulin receptors are G-protein coupled

A

False. The Insulin receptor utilises tyrosine kinase.

Q

Receptors and 2nd messengers:

Opioid receptors are G-protein coupled

A

True

Q

Receptors and 2nd messengers:

cAMP is a hydrophobic molecule

A

False. It is hydrophilic.

Q

Receptors and 2nd messengers:

Nitric oxide acts via cAMP

A

False. It acts via cGMP.

Q

The following antagonists have agonist properties:

Ranitidine

A

False. It is an H2-receptor antagonist.

Q

The following antagonists have agonist properties:

Prazosin

A

False. It is a selective alpha1-adrenoreceptor blocker.

Q

The following antagonists have agonist properties:

Pindolol

A

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.

Q

The following antagonists have agonist properties:

Naltrexone

A

False. It is an opioid receptor antagonist.

Q

The following antagonists have agonist properties:

Xameterol

A

True. It is a mixed beta-agonist/antagonist.

Q

Regarding negative exponential processes:

The rate of decay varies with time

A

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.

Q

Regarding negative exponential processes:

The time constant is longer than the half-life

A

True. An exponential process is said to be complete after 3 time constants, as opposed to 5 half-lives.

Q

Regarding negative exponential processes:

The time constant is the natural logarithm of the half-life

A

False. The time constant is the reciprocal of the rate constant.

Q

Regarding negative exponential processes:

Is converted into a straight line by a semi-log plot

A

True. This is true of other exponential processes also. It allows for easier interpretation.

Q

Regarding negative exponential processes:

The time constant is the time for the process to complete if the rate continued at its initial speed

A

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.

Q

Receptors:

Drug affinity depends on the attraction between receptors and drugs

A

True. Affinity is the ability of a ligand to bind to a specific receptor.

Q

Receptors:

Thyroid hormones bind to cell surface receptors

A

False. They bind to intracellular receptors.

Q

Receptors:

Acetylcholine receptors have 2 alpha and 2 beta subunits

A

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).

Q

Receptors:

Midazolam acts at GABAb receptors

A

False. It acts at GABAa receptors.

Q

Receptors:

Nicotinic hormones bind to intracellular receptors

A

False. Nicotinic receptors are type 1 receptors according to Urquhart’s calssification - membrane bound ligand gated ion channels.

Q

Regarding chemical bond strength:

Van der Waals > Hydrogen > Ionic > Covalent

A

False

Q

Regarding chemical bond strength:

Covalent > Ionic > Hydrogen > Van der Waals

A

False

Q

Regarding chemical bond strength:

Covalent > Hydrogen > Ionic > Van der Waals

A

False

Q

Regarding chemical bond strength:

Ionic > Covalent > Hydrogen > Van der Waals

A

True

Q

Regarding chemical bond strength:

Van der Waals > Hydrogen > Covalent > Ionic

A

False

Q

The following processes are mediated by cAMP:

Decreased heart rate

A

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

Q

The following processes are mediated by cAMP:

Liver carbohydrate metabolism

A

True. Beta2-adrenoreceptors are G-protein coupled, and their stimulation causes increased cAMP and subsequent glycogenolysis (also increases insulin and glucagon secretion).

Q

The following processes are mediated by cAMP:

Increased contractility

A

True. Beta1-adrenoreceptors are G-protein coupled, and their stimulation causes increased cAMP and subsequent increase in contractility.

Q

The following processes are mediated by cAMP:

Triglyceride breakdown

A

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.

Q

The following processes are mediated by cAMP:

Smooth muscle relaxation

A

True. Beta2-adrenoreceptors are G-protein coupled, and their stimulation causes increased cAMP and subsequent smooth muscle relaxation.

Q

Which of the following may alter drug response:

Tachyphylaxis

A

True. Tachyphylaxis is defined as a decreased response following a single administration of a drug.

Q

Which of the following may alter drug response:

Changes in receptor number

A

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).

Q

Which of the following may alter drug response:

Hypersensitivity reactions

A

True

Q

Which of the following may alter drug response:

Idiosyncratic drug responses

A

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.

Q

Which of the following may alter drug response:

Tolerance

A

True. Tolerance is the decreased responsiveness following repeated drug adminsitration.