Pharmacodynamics

Question 1

Radioactive Iodine

Answer 1

Iodine is actively concentrated in the thyroid and the radiation will destroy all tissue within 2-3mm causing focal, controlled destruction

Question 2

How does down regulation of receptors occur?

Answer 2

Internalizing the receptors in lysosomes, recycling them, sequestering or degrading.

Part of normal cellular metabolism

Tolerance

Tachyphylaxis

Question 3

Down Regulation of Receptors

Answer 3

Number of receptors decreases and therefore a reduction in the effect

Question 4

Full Agonist

Answer 4

Binds to the receptor to elicit a maximal response

Question 5

Examples of non receptor biological reactions

Answer 5

Voltage Gated Channels

Enzymes

Carrier Proteins

Question 6

Targets for drug reaction are divided into what two categories

Answer 6

Physical Interactions

Biological Interactions

Question 7

Common receptor for secretory and smooth muscle functions whre the changes occur over seconds.

Answer 7

Metabotropic Receptors

Question 8

Nonspecific drug effects occur in (physical/biological) interactions

Answer 8

Physical Interactions

Question 9

Examples of nonspecific drug effects

Answer 9

Osmotic Diuretics

Antacids

Radioactive Iodine

Question 10

Drug effects on Voltage Gated Channels

Answer 10

Blocking of ion channels can occur by the drug moleucle physically obstructing the channel to impair ion movment. Drug may also modulate the opening/or closing of the channel

Question 11

The straight portion of the sigmoidal drug response curve falls between what range? This corresponds to what?

Answer 11

20-80%

Therapeutic Range

Question 12

Ionotropic Receptors

Question 13

Steroids and thyroid hormones are examples of what type of receptor, new protein production starts over the course of hours

Answer 13

Nuclear Receptors

Question 14

Mixed Agonist - Antagonist

Answer 14

Acts as an agonist in one type of receptor and as an antagonist on other types of receptors

Question 15

Side Effects

Answer 15

Secondary to the intended effect and may be good or bad

Question 16

Agonist

Answer 16

Mimics the effect of the endogenous ligand

Question 17

Toxic Effects

Answer 17

Responses to a drug that are harmful to the health or life of the animal

Question 18

Efficacy

Answer 18

Maximal effect a drug can have

Question 19

Types of pharmacodynamic receptors

Answer 19

Ionotropic Receptors

Metabolic Receptors

Kinase-Coupled Receptors

Nuclear Receptors

Question 20

Antacids (Direct Neutralizers)

Answer 20

Given orally they direct interact with acid in the GI tract, a form of physiologic antagonism

Question 21

Drug effects on Enzymes

Answer 21

Drugs can be analogs that compete with the real substrate for binding to the enzyme, prodrugs where the drug needs to be metabolized into its active form or can act as false substrates which will lead to the formation of abnormal metabolites instead of active product.

Question 22

Lethal Dose 50 (LD₅₀)

Answer 22

Dose which kills 50% of animals

Question 23

Ceiling effect

Answer 23

A partial agonist may never be able to achieve full efficacy

Question 24

Osmotic Diuretics

Answer 24

Molecules move through the body dragging water with them by osmosis until they are excreted

Question 25

Partial Agonist

Answer 25

Will bind to the receptor but not cause as much effect as a full agonist, it does prevent anything else from binding to the receptor while docked there

Question 26

Effective Concentration 50 (EC₅₀)

Answer 26

Concentration at which a drug produces 50% of its maximal effect, only applies to in vitro preparations useful to compare the efficacy of different ligands

Question 27

Onset of Action (Latent Period)

Answer 27

Time required after drug administration for a response to be observed

Question 28

T/F: Endogenous neurotransmitters often bind to more than one type of receptor. The same signaling molecule can then cause different effects or have different affinity in different tissues or species.

Answer 28

True

Question 29

A low therapeutic index indicates a (safe/dangerous) drug

Answer 29

Dangerous

Question 30

Chemical Antagonism

Answer 30

Two drugs chemically inactivate each other

Question 31

Therapeutic Effects

Answer 31

Effects that clinicians want

Question 32

Quantification of drug response typically gives what type of curve when plotted on semi-log paper

Answer 32

Sigmoidal Curve

Question 33

Drugs can bind and activate or prevent from opening, often involved in fast neurotransmission.

Answer 33

Ionotropic Receptors

Question 34

Adverse Effects

Answer 34

Unintended and unwanted, this includes not producing the clinical effect

Question 35

Insulin receptors and growth promoting hormones and factors are of these type of receptors.

Answer 35

Kinase-Coupled Receptors

Question 36

Therapeutic Index

Answer 36

Ratio of LD₅₀ and ED₅₀

Question 37

Potency

Answer 37

Comparison of the concentratio of two drugs needed to induce the same magnitude effect

Question 38

Up Regulation of Receptors

Answer 38

Increase in the number of receptors, resulting in increase in the effect of drug

Question 39

Duration of Action

Answer 39

Length of time that a drug is effective - from onset of action until termination of action

Question 40

Nuclear Receptors / Transcription Factor Receptors

Answer 40

Located in the cytoplasm but after ligand binds translocate to the nucleus of the cell and bind to a response element within the DNA to initiate specific gene transcription

Question 41

Pharmacodynamics

Answer 41

Efects of drugs and their mechanism of action within the body

Question 42

Drug effects on Carrier Proteins

Answer 42

Some small, polar molecules cannot cross cell membranes and get carried in and out by carrier proteins. Drugs may alter this movement either preventing re-uptake of a molecule which increases its levles or preventing output of a molecule to decrease its levels

Question 43

Pharmacokinetic antagonsim

Answer 43

Drug alters ADME of another drug and reduces its effect

Question 44

Antagonist - Neutral Agonist

Answer 44

Binds to the receptor but does nothing on its own, however it sits and prevents anything else from binding and thus blocks the receptor

Question 45

Non-Competitive Antagonism

Answer 45

Ligand that interacts somewhere other than the receptor but causes a change in the receptor that blocks its ability to bind to the normal ligand

Question 46

A high therapeutic index indicates (safe/dangerous) drug

Answer 46

Safe

Question 47

Kinase-Coupled Receptors

Answer 47

Transmembrane proteins have an extracellular receptor portion and an intracellular portion that has enzymatic activity. Phosphorylation and activation of proteins activate effectors

Question 48

Physiologic Antagonism

Answer 48

Drugs have opposite effects that cancel each other out

Question 49

Ligand

Answer 49

Anything that binds to a recognition site

Question 50

Competitive Antagonism

Answer 50

Antagonist ligand binds and releases as long as it is present and so if the antagonist is present as well as an agonist they will compete for the binding, who binds more often will be determined by the concentration and affinity

Question 51

Metabotropic Receptors

Answer 51

G protein receptors (7TM) receptors, transduce an extracellular signal to an intracellular one by activating the G-Protein second messanger system \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Allow for signal amplification and specificity

Question 52

Biological interactions include

Answer 52

Receptors Non Receptors

Question 53

Effective Dose 50 (ED₅₀)

Answer 53

Dose that produces a result (usually desired) in 50% of the animals

Question 54

Reverse Agonist

Answer 54

Will bind to the receptor and cause the opposite effect as the endogenous ligand would