CHEM 455 EXAM 3 Flashcards

1
Q

Drug resistance

A

formerly effective drug dose is no longer effective

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

drug synergism

A

synergism arises when the therapeutic effect of two or more drugs used in combination is greater than the sum of the effect of the drugs individually

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

5 types of drug synergism

A
  1. Inhibition of a Drug-Destroying Enzyme
  2. Sequential Blocking Inhibition
  3. Inhibition of Targets in Different Pathways
  4. Efflux Pump Inhibitors
  5. Use of Multiple Drugs for the Same Target
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

why is resistance a problem

A

it causes drugs to be inhibited and ineffective which can be costly and deadly

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

why is drug synergism important

A

important in order to both combat drug resistance and to improve effectiveness of drugs

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

what are the 8 mechanisms of drug resistance

A
  1. Altered target enzyme or receptor
  2. overproduction of the target enzyme or receptor
  3. overproduction of the substrate or ligand for the target protein
  4. increased drug destroying mechanisms
  5. decreased drug (prodrug) activating mechanism
  6. activation of new pathways circumventing the drug effect
  7. reversal of drug action
  8. altered drug distribution to the site of action-modified cell membrane
  9. altered drug distribution to the site of action-efflux pumps
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Altered Target Enzyme or Receptor

A

mutation of AA residue→ drug binds poorly, but substrate binding is unchanged

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

Overproduction of the Target Enzyme or Receptor

A
  • induction of extra copies of the same gene encoding the target protein
  • taking a larger dose may help until is reaches toxic levels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Overproduction of the Substrate or Ligand for the Target Protein

A

-overproduction of the substrate for a target enzyme would competitively block the ability of the drug to bind at the active site

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

Increased Drug-Destroying Mechanisms

A

-resistance by induction of genes→ produce new enzymes, increase quantities of existing enzymes, or produce other substances to degrade or sequester the drug

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

Decreased Drug (Prodrug)-Activating Mechanism

A

Prodrug- compound that is converted to the active substance after its administration

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

Activation of New Pathways Circumventing the Drug Effect

A

-if the drug inhibits an enzyme that blocks production of a metabolite, the organism could induce a new metabolic pathway that produces the same metabolite

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

Reversal of Drug Action

A

-drug acts in the opposite way that it is supposed to

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

Altered Drug Distribution to the Site of Action- Modified Cell Membrane

A
  • organism excludes the drug from the site of action by preventing cellular uptake of the drug
  • adjust net charge of plasma membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Altered Drug Distribution to the Site of Action- Efflux Pumps

A
  • Efflux pumps- transmembrane proteins that act as transporters to carry drugs out of the cell before they elicit their therapeutic effect
  • multidrug resistance pumps- broad specificity transporters that efflux a wide range of drugs against microorganisms and tumor cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are the factors that affect metabolism

A

increased lipophilicity increases metabolism

species, strain, sex, age, hormones, pregnancy, liver diseases, other drugs you’re taking

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

what are the two primary routes of metabolism for drugs and how do they differ

A
  1. via mouth: it is absorbed through small intestine/stomach-> blood stream -> liver
    drugs metabolized by liver enzymes are presystemic or first pass effect
  2. avoid liver
    -sublingual, rectal, IV, IM, subcutaneous injections, pulmonary absorption, topical application
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

how is drug metabolism studied

A

mass spectrometry, radioactive labels, HPLC/NMR

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

Principal steps in drug metabolism studies

A
  1. Sample preparation– extractions, ion exchange—sometimes omitted and urine injected directly into HPLC
  2. Separations – HPLC, gas chromatography (GC), and capillary electrophoresis (CE)
  3. Identification – mass spectrometry (MS), NMR: link to separation with LC-MS, GC-MS, or CE-MS; good for
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

why are prodrugs used

A

aqueous solubility, absorption and distribution, site specificity, instability, prolonged release, toxicity, poor patient acceptability, formulation problems, delivery of nucleoside drugs

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

what is carrier prodrug

A

a compound that contains an active drug linked to a carrier group that is removed enzymatically

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

types of carrier prodrug

A

bipartite: comprised of a carrier attached to a drug
tripartite: carrier connected to a linker that is connected to a drug
mutual (codrug): two usually synergistic drugs that are attached to each other

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

bioprecursor prodrug

A

a compound that metabolized by molecular modification into a new compound, which is a drug or is metabolized further to a drug- or just simple cleavage of a group from the product

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

why are esters the most frequently used prodrug moiety

A
  • Esterases are ubiquitous
  • can prepare esters with any degree of hydrophilicity or lipophilicity
  • ester stability can be controlled by appropriate electronic and steric manipulations
  • both alcohols and carboxylic acids can be esterified
  • based on environment and what is needed you can slow down rate or increase it
25
Q

to accelerate the hydrolysis rate of esters

A
  • attach EWG if a base hydrolysis mechanism is important

- attach an electron donating group if an acid hydrolysis mechanism is important

26
Q

to slow down hydrolysis rate

A
  • make sterically hindered esters

- make long chain fatty acid esters

27
Q

why does bodor’s redox tripartate prodrug delivery work so well for CNS drug delivery and why is it generally not toxic

A

oxidation of the dihydropyridine to the pyridinium ion prevents the drug from escaping out of the brain because it becomes charged
- this drives equil of lipophilic precursor throughout all the tissues of the body to favor the brain

28
Q

why are McGuigan’s ProTides so effective

A
  • Increases cellular delivery of the nucleoside
  • Overcomes the rate-limiting monophosphorylation step- delivers the monophosphate form
  • Pieces that form the ProTide prodrug are not toxic
  • nucleosides/monophosphates are very polar and the ProTides masks this allowing it to cross the membrane
29
Q

How does Rohypnol interact with GABA, the major inhibitor of neurotransmission in the brain?

A

Rohypnol increases the affinity of GABA for its receptors, thus decreasing the excitation of nerve systems resulting in reduction of anxiety and alertness

30
Q

What is the general role of benzodiazepines, such as Rohypnol?

A

Benzodiazepines like Rohypnol are central nervous system (CNS) depressants that result in sedative-hypnotic activity

31
Q

What are the two key substituents of Rohypnol that contribute to its enhanced sedative-hypnotic activity?

A

The nitro group and the o-fluoro group of the phenyl group produce increased sedative-hypnotic activity compared to other benzodiazepines

32
Q

Why did drug developers think that Mibefradil would be a better drug than its counterparts

A

It is highly selective for T type calcium channels

33
Q

What alternative purposes is Mibefradil being studied for now? What further research is being done now

A

Its structural analogs are being studied, its anticancer properties are also being studied

34
Q

Why was thalidomide initially taken off of the market and how did it affect drug safety regulations?

A

Thalidomide was taken off the market because it had been linked to birth defects. Drug safety regulations became stricter and required animal testing and tightly controlled human testing before going on the market.

35
Q

List two conditions/ailments that thalidomide has been used to treat.

A

Leprosy (ENL), multiple myeloma, morning sickness, insomnia, Crohn’s disease, graft-versus-host disease, recurrent mouth ulcers, sarcoidosis

36
Q

If the S-enantiomer isomer of thalidomide is the problem child, why can’t we just use its safer and effective R-enantiomer?

A

The R-enantiomer of thalidomide will racemize in the body, forming a racemic mixture.

37
Q

Name three common symptoms of ADHD.

A

inattention, hyperactivity, impulsivity

38
Q

Provide the name of at least one neurotransmitter that is up-regulated by Adderall

A

Dopamine, serotonin, norepinephrine

39
Q

List two common side effects of Adderall use

A

difficulty sleeping, irritability, nausea/vomiting, loss of appetite/taste, restlessness and dry mouth, abnormal heart rate, high blood pressure, hallucinations, continued painful erections

40
Q

What makes HUMIRA different than the other monoclonal antibodies?

A

HUMIRA is a fully human monoclonal antibody. The ones preceding Adalimumab (such as Etanercept) were combinations of a human and mouse antibody.

41
Q

Why doesn’t HUMIRA have normal ADME studies?

A

you cannot perform traditional ADME studies on an antibody

42
Q

Why does HUMIRA cause an increased risk of infection?

A

The drug acts as an anti-inflammatory agent by binding to TNF alpha, causing a weakened
immune response to xenobiotics and other pathogens, thus increasing risk of infection

43
Q

Name two advantages and two disadvantages of Hetlioz

A
Advantages may include:
Only one on the market
Doesn’t affect receptors and enzymes 
­ Non-­habit forming
Disadvantages may include:
­ Expensive
­ Headaches
­ Increased urinary and upper respiratory infections
­ Need to take with food so poor patient compliance
44
Q

Flibanserin acts as a full agonist to HTRA1 and as an antagonist to HTRA2. What ligand found in the brain normally binds to these receptors?

A

Serotonin

45
Q

Identify if the following neurotransmitters are upregulated or downregulated by Flibanserin: dopamine, norepinephrine, and serotonin

A

Dopamine, upregulated| norepinephrine, upregulated| serotonin, downregulated

46
Q

Does Flibanserin (the “female Viagra”) function in the same way as Viagra? In other words, does Flibanserin cause increased blood flow to the genital region? Explain in 1 sentence the major difference between the two.

A

No, Flibanserin affects the chemical balance in the brain while Viagra affects the flow of blood to the genital region.

47
Q

Why shouldn’t Albuterol be used along with MAO inhibitors?

A

Taking Albuterol along with MAO inhibitors increases risk of tachycardia and agitation. Cheese Effect.

48
Q

What role does cAMP play in the the regulation of Albuterol?

A

cAMP decreases Ca2+ concentration within the cell which leads to smooth muscle relaxation and bronchodilation.

49
Q

Why does it make sense that Albuterol is distributed as a racemic mixture?

A

Both enantiomers fulfill a different role and work synergistically. Also, time and money spent isolating the enantiomers is avoided.

50
Q

What is the function of esomeprazole magnesium?

A

Proton pump inhibitor

51
Q

How does esomeprazole magnesium associate with its receptors?

A

Covalent disulfide bonds with cysteine

52
Q

Which isomer of omeprazole functions best in humans?

A

S - isomer

53
Q

List a combination of four side effects and common uses for doxycycline

A
  • Increased photosensitivity, GI effects, discoloration of teeth in children, candidiasis
  • Rocky Mountain Fever, Chlamydia, UTIs, acne, staph, cholera
54
Q

What type of bacterial agent is doxycycline?

A

Bacteriostatic

55
Q

What two functional groups are common to doxycycline’s pharmacophore

A

Ketones and Alcohols

56
Q

What are the two receptors that esketamine targets?

A

Dopamine Reuptake Transporter

NMDA Receptor

57
Q

How was ketamine administered and how is esketamine going to be administered?

A

Ketamine is administered as an IV, esketamine will be administered through a nasal spray

58
Q

What was ketamine originally used as, and because of this, what are some of the side effects of esketamine?

A

Ketamine was originally used as an anesthetic, and because of this some of its side effects include hallucinations and dissociation/derealisation