Exam 1: Pharmacodynamics Flashcards

1
Q

T/F Drugs being a solid/liquid/gas does NOT affect the route of administration

A

False; all 3 affect the route of administration

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2
Q

How is drug size expressed in units?

A

Daltons

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3
Q

What size are most drugs?

A

100-1000 MW

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4
Q

Can a drug diffuse if it is >1000 MW?

A

No; the drug is too big and will not diffuse as readily

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5
Q

What mechanism can describe how receptors and drugs bind together?

A

Lock and key mechanism; Drugs have a specific structure and fit/bind into a specific receptor

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6
Q

What 4 things affect receptor interactions?

A
  1. Appropriate size
  2. Electrical charge
  3. Shape
  4. Atomic composition
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7
Q

What are the 3 main types of chemical bonds seen with receptors?

A
  1. Covalent
  2. Electrostatic (charged molecules, hydrogen bonds, Van der Waals forces)
  3. Hydrophobic (lipid-soluble drugs)
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8
Q

Which bond type is the strongest? Which is the weakest?

A

Covalent = Strongest
Hydrophobic = Weakest

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9
Q

How do bond strength and specificity relate to one another?

A

They are inversely related to one another; As bond strength increases, specificity decreases and as bond strength decreases, specificity increases

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10
Q

What is specificity?

A

How specifically a drug has to fit into a receptor site to elicit an effect

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11
Q

Are agonists endogenous, exogenous, or both?

A

Both

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12
Q

What happens when an agonist binds to a receptor?

A

It elicits a downstream response

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13
Q

What are isomers?

A

Compounds with the same chemical equation but different shapes

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14
Q

Why are isomers important in pharmacology?

A

Drugs are optical isomers; each isomer has different effects on the body and in pharmacology, we take an average of the two isomers and give the racemic mixture to the patient

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15
Q

What drug is an example of a racemic mixture?

A

Esketamine = purified form of Ketamine

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16
Q

What 3 things affect the duration of drug action?

A
  1. How long the drug binds and releases from the receptor
  2. How long the downstream effect is and what type of bonds are present (if it is a covalent bond the receptor will need to be degraded)
  3. Desensitization (cells being shut down via signalling processes)
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17
Q

What are the 2 properties of “good” receptors?

A
  1. Selective - binds to one receptor/type of receptor
  2. Alteration - the ligand binds to the receptor and has some sort of conformational change to cause a downstream effect
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18
Q

What are “bad” receptors?

A

Non-regulatory molecules that bind drugs with no detectable change

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19
Q

What are 2 properties of “bad” receptors?

A
  1. “Inert binding sites” - a binding site where the drug binds but nothing changes at all
  2. Drug carriers - they can carry drugs but they won’t have an effect on the body
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20
Q

What is the most important drug carrier?

A

Albumin

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21
Q

When a plasma protein is bound to a drug, can it cross barriers? Why or why not?

A

No; albumin is too large to cross barriers

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22
Q

T/F When plasma protein is unbound, it can cross barriers.

A

True

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23
Q

What is another name for the “unbound form” of something?

A

The free form

24
Q

Is albumin a bad or good receptor?

A

Bad

25
Q

How does a decrease in the amount of albumin affect how much of a drug you need to give a patient?

A

Patients with a lower level of plasma will have a higher level of the free form of the drug. This will cause a bigger effect and potentially toxic effects than with a patient who has normal levels of plasma

26
Q

Albumin binds mostly to ___ drugs

A

Acidic

27
Q

Alpha1-acid glycoproteins bind mostly to ____ drugs

A

Basic

28
Q

Lipoproteins bind mostly to ___ drugs

A

Neutral

29
Q

Describe an agonist mimic/indirect agonist

A

Indirect agonists are those that increase the level of direct agonists often by reducing the rate of metabolism of the direct agonist “downstream”

30
Q

What is a competitive antagonist?

A

Bind to receptor and inhibit agonist response. Surmountable.

31
Q

Describe a partial agonist

A

Produces a lower response at full receptor occupancy. Acts as an antagonist in the presence of a full agonist.

32
Q

Describe physiologic antagonist/antagonism

A

Drugs that act at different receptors to squelch the effect of other drugs.

Example: acetylcholine, bound to another receptor, inhibits the effect of epinephrine.

33
Q

Describe receptor theory

A

theorizes that a receptor oscillates (on its own) between an active (Ra) and inactive state (Ri).

34
Q

What is an inverse agonist?

A

binds to a receptor and forces it toward its inactive state. In practice it is a really strong agonist.

35
Q

Beta-1 Receptor “Direct agonist” (Example)

A

Epinephrine, Norepinephrine

36
Q

Beta-1 Receptor “Indirect agonist” (Example)

A

Amphetamine, cocaine

37
Q

Beta-1 Receptor “Partial agonist” (Example)

A

Pindolol, Acebutolol

38
Q

Beta-1 Receptor “Antagonist” (Example)

A

Propranolol, Atenolol

39
Q

Beta-1 Receptor “Inverse agonist” (Example)

A

Carvedilol, Nadolol

40
Q

Name two GOOD receptor properties

A

Selective: specific to a certain drug(s)
Alteration: receptor changes conformation to illicit a change inside the cell

41
Q

What is a BAD receptor property?

A

Bind drugs with no detectable change in function. i.e drug carriers (albumin) binds drugs so they can’t reach destination.

42
Q

What type of drugs does albumin mostly bind to? (neutral, acidic, or basic)

A

Acidic

43
Q

Define Potency

A

concentration (EC 50) or dose (ED 50) of a drug to produce 50% of that drugs maximal effect

44
Q

Define [maximal] Efficacy

A

the greatest possible response a drug can deliver.

45
Q

What is the ED50?

A

The median effective dose is the dose that produces a therapeutic response in 50% of people

46
Q

What is the LD50?

A

Lethal dose. The dose that is lethal in 50% of people

47
Q

What is the TD50?

A

Toxic dose. The dose that results in toxic effects in 50% of people.

48
Q

Describe therapeutic index

A

TI establishes a margin of safety. A wide TI means that it takes more of that drug, to produce toxic effects, than a drug with a low TI. TI = TD50/ED50

49
Q

What are 2 reasons drug responsiveness varies among people?

A

drug-drug interactions
genetic factors (hypo-reactive, hyper-reactive)

50
Q

In order to cross barriers, drugs need to be charged? (T/F)

A

False - need to be uncharged

51
Q

Weak acids: if pH < PKA
protinated/unprotinated?
Charged/uncharged?

A

Protinated
Uncharged

52
Q

Weak acids: if pH > PKA
protinated/unprotinated?
Charged/uncharged?

A

Unprotinated
Charged

53
Q

Weak Bases: if pH > PKA
protinated/unprotinated?
Charged/uncharged?

A

Unprotinated
Uncharged

54
Q

Weak Bases: if pH < PKA
protinated/unprotinated?
Charged/uncharged?

A

Protinated
Charged

55
Q

Weak acids are excreted faster in alkaline urine (T/F)

A

True

56
Q

Weak bases are excreted faster in acidic urine (T/F)

A

True

57
Q

What are biologic drugs? (i.e monoclonal antibodies)

A

Drugs created by living organisms.
Extracted from living systems