Lecture 2 Pharmacodynamics and Pharmacokinetics Test 1 Flashcards

1
Q

Activation of protein receptors causes a ________________.

A

Conformational change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the drug effect related to?

A

The number of bound receptors.

Ie: Paralytics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

____________ activates receptors by binding to them.

A

Agonist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are 3 reversible bonds?

What bond is irreversible?

A

Ion (opposite charges), Hydrogen (electronegative atoms), and Van der Waals interaction (repulsive attraction)

Covalent bonds (strongest bond)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

____________ binds to a receptor but does not activate the receptor, the get in the way of the endogenous ligand.

A

Antagonist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Increasing amounts progressively inhibit the agonist and shift the dose-response curve to the right.

A

Competitive antagonism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Even high concentrations of agonist can’t cause the agonist event.

A

Noncompetitive antagonism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Binding to a receptor (usually at agonist site).
Causes less response than the agonist even at a supramaximal dose.

A

Partial Agonist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Compete for the same site as the agonist but produces the opposite effect.

A

Inverse Agonist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Even high concentrations of agonists can’t cause the agonist event.

A

Noncompetitive antagonism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The number of receptors are not __________.

A

Static

Receptors can increase or decrease depending on comorbidity and drug therapy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is tachyphylaxis?

A

Quick tolerance, down-regulation of receptors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

In pheochromocytoma, there is a ___________ in beta receptors in response to an increase in ____________.

A

decrease; catecholamines

Tolerance builds up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Receptors are classified by _____________.

A

Location

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What 3 areas can receptors be located?

A

Lipid Bilayer
Intracellular Proteins
Circulating Proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Most of the anesthetic drugs that we give have receptors located in the _____________.

Examples?

A

Lipid Bilayer (Membrane Bound)

Opioids, BZDs, Beta-blockers, catecholamines, NMBD.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are examples of drugs that bind to intracellular proteins?

A

Insulin, Steroids, Milrinone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are examples of drugs that bind to circulating proteins?

A

Anticoagulants

Anticoagulants that are free or unbound will cause drug effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the quantitative study of injected and inhaled drugs and their metabolites? What the body does to the drug.

What are the 4 components?

A

Pharmacokinetics

Absorption
Distribution
Metabolism
Excretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Pharmacokinetics determines the concentration of the drug in the ____________ and at the _______________. This varies significantly from patient to patient.

A

Plasma and Effector Site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the one-compartment model?

A

Immediately after drug injection, the concentration of the drug is diluted by plasma in a central compartment, resulting in a small volume of distribution, and excreted immediately.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the vessel-rich group?

A

A small percentage of the body mass (brain, kidney, heart, lungs) that makes up a large percentage of cardiac output.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the two-compartment model?

A

The drug goes into a central compartment and then peripheral compartments (muscles, fats, tendons, ligaments).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

For plasma protein receptors, what do acidic drugs bind to?

What do alkalotic drugs bind to?

A

Acidic drugs bind to albumin.

Alkalotic drugs bind to Alpha 1- Acid Glycoprotein.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Only __________ drug can cross cell membrane (distribution) and can determine the concentration available to receptor (potency)
Free unbound drug
26
Name factors that can decrease plasma protein.
Age Hepatic Disease Renal Failure Pregnancy Burns Sepsis
27
If the normal free fraction of the drug is 2% and half the plasma proteins are lost, then the free fraction of the drug is _______%.
4%, it doubles.
28
Poor protein binding and lipophilic drugs have a ____________. Examples
Greater Volume of Distribution (escapes plasma) Examples: Thiopental and Diazepam
29
Highly protein-bound drugs to plasma protein will result in a ____________. Examples
Smaller Volume of Distribution (stays in plasma) Example: Warfarin
30
What is metabolism?
Usually conversion of an active drug to an inactive drug from lipid-soluble drugs to water-soluble and inactive metabolites (usually). Then kidneys pee it off.
31
What are some active metabolites?
Diazepam (Valium) Propanolol (Inderal) Morphine Prodrugs such as Codeine
32
How are most anesthetic drugs metabolized? What are three other ways drugs are metabolized?
Through the **Hepatic Microsomal Enzymes**. Plasma (Hoffman Elimination, ester hydrolysis) Kidney Tissue Esterase (GI Tract, Placenta)
33
What does phase 1 metabolism involve? What does phase 2 metabolism involve?
Phase 1: Increase polarity and prepare for phase II reactions *Oxidation* *Reduction* *Hydrolysis* Phase 2: Covalently link with a high polar molecule to become water soluble *Conjugation*
34
What is the large family of hepatic microsomal enzyme called consisting of 10 isoforms that are membrane-bound and contain a heme cofactor?
CYP 450
35
What specific enzyme makes up 60% of CYP 450 activity and metabolizes over half of the drugs?
CYP3A4
36
What drug will induce hepatic microsomal enzymes?
Phenobarbital *Drugs like opioids and BZD will have less effect*
37
What food will inhibit hepatic microsomal enzymes?
Grapefruit Juice *Increases concentration of drug/ toxicity levels*
38
Acute ingestion of alcohol will require the patient to receive ____________ anesthetics. Chronic use of marijuana will require the patient o receive _____________ anesthetics.
Less (acute EtOH intake) *Dr. Kane correction email* More (chronic marijuana)
39
For most anesthetic drugs, the hepatic clearance is __________. The rate is proportional to ____________.
Constant Concentration (*More Drug/More Clearance to a certain point since the liver capability is not unlimited*)
40
What is the rate of drug metabolism equation? What are the two limitations to this equation?
Rate = Cardiac Output (Concentration Inflow - Concentration Outflow) Flow limitation (Cardiac output) and capacity limitation (liver's metabolizing ability)
41
What are the three things involved in Renal Clearance?
1. GFR 2. Active Tubular Secretion 3. Passive Tubular Reabsorption
42
Differentiate between Elimination Half Time vs Elimination Half-Life.
Elimination half-time is the time necessary to eliminate 50% of the drug from **PLASMA** after a bolus dose. Elimination half-life is the time necessary to eliminate 50% of the drug from **BODY** after a bolus dose.
43
You give 100 mcg of drug A. E 1/2 is 10 minutes. In 20 minutes what will plasma concentration be? If you reinject 100 mcg of drug A, 20 minutes later what will the plasma concentration be?
25 mcg 31 mcg
44
What is the time to a 50% decrease after **infusion** is discontinued?
Context Sensitive Half-Time
45
What drugs have a short context-sensitive half-time?
Sufentanil Alfentanil Propofol
46
What drugs have a long context-sensitive half-time?
Fentanyl Thiopental
47
What does it mean when the pK (dissociation constant) and pH are identical?
50% of the drug is ionized and 50% of the drug is non-ionized.
48
What drug is a weak acid? What drug is a weak base?
Weak acid: Barbituates, Thiopental Weak bases: Local Anesthetics, Opioids
49
Acids ionized in an _____________ environment. Bases ionized in an _____________ environment.
Alkalotic Acidic
50
Describe non-ionized drug molecules in terms of their Pharmacological Effect: Solubility: Cross lipid barriers: Renal Excretion: Hepatic metabolism:
Describe non-ionized drug molecules in terms of their Pharmacological Effect: Active Solubility: Lipids Cross lipid barriers: Yes Renal Excretion: No Hepatic metabolism: Yes
51
Describe ionized drug molecules in terms of their Pharmacological Effect: Solubility: Cross lipid barriers: Renal Excretion: Hepatic metabolism:
Describe ionized drug molecules in terms of their Pharmacological Effect: Inactive Solubility: Water Cross lipid barriers: No Renal Excretion: Yes Hepatic metabolism: No
52
Weak acid (pK 7.6) is put in a basic pH (blood 7.8). Ionized or non-ionized?
Ionized Because it is a weak acid, pK will go after the pH. pH - pK 7.8 - 7.6 = +0.2
53
Weak base (pK 8.0) is put in basic pH (blood 7.2) Ionized of non-ionized?
Ionized Because it is a weak base, pK will go before the pH. pK - pH 8.0 - 7.2 = +0.8
54
Spinal Anesthetic is a weak base (pK 7.3), fetal pH is 6.8, and the mother's pH is 7.4. Will the drug be ionized or non-ionized in the fetus and mom?
The anesthetic will be ionized in the baby, the drug will be trapped in the fetus. The anesthetic will be non-ionized in the mom, the drug will be active. Because spinal anesthetic is a weak base pK will go before pH pK - pH Fetus: 7.3 - 6.8 = +0.5 Mom: 7.3 - 7.4 = -0.1
55
Pt with an ischemic foot requested an ankle block. Will surgical anesthetic work? An opioid is a weak base with a pK of 8.0. Normal Tissue pH = 7.4 Ischemic Tissue pH = 6.6
No, a surgical anesthetic will not work. The drug will be ionized in normal tissue and ischemic tissue. With a weak base, pK is before pH. Normal Tissue: 8.0 - 7.4 = +0,6 (ionized) Ischemic Tissue: 8.0 - 6.6 = +1.4 (very ionized)
56
What the drug does the to the body. This is figured out by measuring concentrations at different pharmacological responses.
Pharmacodynamics
57
There is individual variability in pharmacodynamics in the elderly due to what 3 factors?
Decrease Cardiac Output to the Brain and Liver Decrease Protein Binding Increase Body Fat
58
Individual variability in pharmacodynamics includes what 3 things?
Enzyme activity Genetic Disorders Elderly
59
Concentration vs Response.
Potency Less Drugs with more effect = more potent
60
The ability of a drug to produce a clinical effect.
Efficacy
61
Time to drug effect, the lag time between administration (plasma concentration) and effect.
Relative Potency
62
The dose required to produce effect in 50% of patients.
ED50
63
The dose required to produce death in 50% of patients.
LD50
64
Ration between LD50 and ED50
Therapeutic Index (T.I.)
65
How drug molecules are structured in 3D.
Stereochemistry
66
Molecules with an asymmetric center, usually related to the way carbon molecules are bonded.
Chiral compounds
67
These structures are chemically identical that are mirror images of each other and can not be superimposed.
Enantiomers
68
In terms of rotation of light in solution, what is the right rotation called? Left Rotation?
Right rotation: Dextrorotary or R (Rectus) Left rotation: Levorotary or S (Sinister)
69
Drug mixture with optical activity of equal compounds that can exhibit different ADME. One enantiomer is active and the other is inactive or has more side effects.
Racemic Mixtures
70
What fraction of drugs are racemic?
1/3
71
___ - Enantiomer of Ketamine is more potent had has less delirium.
S
72
L-Bupivacaine has less _____________ .
Cardiac Toxicity
73
What isomer of atracurium lacks histamine effects?
Cistracurium
74
What is the isomer of albuterol that does not cause tachycardia?
Xopenex (*But not as efficacious as albuterol*)
75
With pharmacogenetic testing, we look for variants in genes that code for _______, ________, and ________.
Drug-metabolizing enzymes Drug targets Immune Proteins