Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Oncology > Antimetabolites > Flashcards

Antimetabolites Flashcards

1
Q

Antimetabolites are cell cycle specific. True or False?

A

True

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

What phase of the cell cycle does anti-metabolites affect?

A

S phase also known as Nucleotide synthesis and DNA replication

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

Inhibiting essential biosynthetic processes, or by being incorporated into DNA and RNA, and inhibiting their normal function describes which class of medications?

A

Antimetabolites

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

Methotrexate and Pemetrexed are what subclass of what class of medications?

A

Folate Inhibitors (Antifolates) of Antimetabolites

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

Name the 2 Antifolates in the Antimetabolite class

A

Methotrexate and Pemetrexed

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

What is the drug target for methotrexate?

A

Dihydrofolate reductase (DHFR)

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

How does MTX inhibit DNA and RNA synthesis?

A

Inhibition of DHFR will inhibit purine and thymidylate biosynthesis, so DNA cannot be replicated

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

Does renal tubular fluid need to be kept basic or acidic when taking MTX and why?

A

Basic because it can cause crystallization and renal failure

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

Methotrexate distributes “moderately” well into CNS and uses renal excretion. True or False?

A

True

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

Myelosuppression, mucositis, gastrointestinal toxicities (stomatitis), and toxicities to normal tissues, requiring leucovorin in certain uses are all select toxicities of what drug?

A

MTX, antifolate, antimetabolite

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

Activated form of folic acid, also known as Folinic Acid, is what safety drug for which drug?

A

Leucovorin for MTX

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

When is Leucovorin needed?

A

For “high dose” MTX 500-12000 mg/m2 requires leucovorin rescue until MTX levels are <0.1 or 0.05 ~ undetectable and within 42 hours (can started 24 hours after end of MTX)

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

At what time would MTX infusion be considered lethal if not given leucovorin?

A

Within 42 hours

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

Leucovorin is titrated according to the MTX serum concentration, when do you start Leucovorin after the end of MTX?

A

20-24 hours after end of MTX

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

Leucovorin is an emergency reversal agent of MTX that clears the drug from the blood. True or False?

A

False. It allows nucleic acid synthesis to proceed even in the presence of MTX because it is converted into Tetrahydrofolate to make products for DNA synthesis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q 
Can Leucovorin be use 
A) to selectively "rescue" cells from adverse effects of MTX 
B) to do rapid enzymatic breakdown
C) to increase the efficacy of 5-FU
D) A & C
A

D – both!

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

What is the emergency reversal for MTX toxicity?

A

Glucarpidase

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

Glucarpidase breaks down MTX to metabolites outside of the cell and eliminates extracellular MTX via rapid enzymatic breakdown. This can be used with or without renal impairment. True or False?

A

False. Used in the scenario of toxic MTX combined with renal impairment. Last resort is HD.

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

5-Fluoropyrimidines are part of which class?

A

Antimetabolites

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

The following are 5-fluoropyrimidines EXCEPT?
A) Decitabine
B) 5-Fluorouracil
C) Capecitabine

A

A: Decitabine is a cytidine analog

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q 
Thymidylate synthase (TS) is a drug target for which drug?
A) MTX 
B) Hydroxyurea
C) Fludarabine
D) 5-FU
A

D: 5-Fluorouracil

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

5-Fluorouracil incorporates itself into RNA, but it does not inhibit thymidylate synthase (TS). True or False?

A

False. It does both mechanisms.

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

5-Fluorouracil can be given as a continuous infusion and it readily penetrates the CNS. True or False?

A

True

24
Q

For a non-continuous infusion of 5-FU, which 2 are dose-limiting toxicities to 5-FU?
A) Hand foot syndrome
B) Mucositis
C) Diarrhea

A

B & C

25
Q

With a 48-72 hour continuous infusion of 5-FU, which 2 are dose limiting toxicities?
A) Hand foot syndrome
B) Mucositis
C) Diarrhea

A

A & B

26
Q 
What is the purpose of continuous infusion for 5-FU? Select all that apply. 
A) Penetrates CNS better 
B) Easier to eliminate for the liver
C) Less myelosuppression
D) Prolonged exposure
A

C & D

27
Q

What phase of the cell cycle dose 5-FU work on?

A

S phase

28
Q 
What is the oral preparation of 5-FU?
A) Capecitabine 
B) Venetoclax 
C) Tamoxifen 
D) Thalidomide
A

A

29
Q

Capecitabine is dosed q24h because it has a longer half life as like a continuous infusion. True or False?

A

False. It is q12h but it does have a longer half life

30
Q

Which of the following are dose limiting toxicities for Capecitabine? Select all that apply
A) N/V/D
B) Myelosuppression
C) Thrombocytopenia
D) HFS (Palmar plantar erythrodysesthesia)

A

A, C, D. Neutropenia is more common with 5-FU and severe myelosuppression is uncommon

31
Q 
Which of the following are cytidine analogs? Select all that apply 
A) Cytarabine
B) Gemcitabine
C) 5-Azacytidine
D) Decitabine
A

ALL OF THEM :-)

32
Q

Cytidine analogs can competitively inhibit DNA polymerase and incorporates into DNA. True or false?

A

True

33
Q

Cytarabine (Ara-C) of the cytidine analogs inhibits DNA polymerase OR incorporates into DNA leading to apoptosis?

A

incorporates into DNA leading to apoptosis

34
Q

7+3 Regimen for AML induction includes which antimetabolite as a continuous infusion for 7 days in combination with daunorubicin or idarubicin to take advantage of pharmacology and cell-cycle specific nature?

A

Cytarabine (Ara-C) 100-200 mg/m2/day

35
Q 
What are the primary toxicities for ara-c? Select 2
A) Myelosuppression
B) Gastrointestinal epithelial injury
C) N/V/D
D) Mucositis
A

A & B

36
Q 
Based on the pharmacology and penetration of Ara-C, what would be a risk(s) when given high dose cytarabine?
A) slurred speech
B) unsteady gait 
C) dementia
D) coma
A

All of these because of Cytarabine’s CNS penetration, it can cause cerebral and cerebellar dysfunction (3-4.5g/m2 for 6-12 doses)

37
Q

Bad methylation is the MOA for which antimetabolite?

A

Azacitidine in the cytidine analogs; Bad methylation helps when there is hypermethylation and silencing of tumor suppression genes. AZA incorporates itself into DNA and RNA and inhibits DNA methyl transferase (DNMT1) and hypomethylation or “bad methylation” occurs gradually causing reactivation of tumor suppression genes.

38
Q 
Which cytidine analog blocks DNA Polymerase?
A) Cytarabine 
B) Gemcitabine
C) 5-Azacytidine
D) Decitabine
A

B - Gemcitabine

39
Q 
Which of the following are part of the subclass purine analogs/inhibitors in the antimetabolite class?
A) Capecitabine
B) 6- Mercaptopurine
C) Azathioprine
D) Hydroxyurea
A

B, C, D + 6- Thioguanine

40
Q 
What is the drug target for Purine Analog/Inhibitor?
A) Ribonucelotide reductase (RR)
B) DNA methyltransferase (DNMT1)
C) Thymidylate synthase (TS)
D) Dihydrofolate synthase (DHFR)
A

A - purine analogs/inhibitor
B - Azacitidine
C - 5-FU
D- MTX

41
Q

6- Mercaptopurine, a purine analog of antimetabolite class, incorporates metabolites into DNA causing miscoding during DNA replication. True or false?

A

True

42
Q

What do polymorphism do you need to check before giving 6-Mercaptopurine? (Hint: Think Azathioprine)

A

Thiopurine methyltransferase (TPMT) polymorphism result in interpatient variability in metabolism and toxicity (myelosuppression)

43
Q

If this drug is given concomitantly with 6-Mercaptopurine, you would have reduce the dose of 6- Mercaptopurine by 75%. Which drug is this? (Hint: Think Azathiopurine)

A

Allopurinol

44
Q 
Myelosuppression, immunosuppression, and susceptibility to all infections (fungal, parasitic, and bacterial infections) are all possible toxicities when given which drug?
A) Fludarabine
B) Cytarabine
C) 6-Mercaptopurine
D) Hydroxyurea
A

6-Mercaptopurine, antimetabolite, purine analog

45
Q

Adenosine analogs, such as Fludarabine + Cladribine, are called false nucleotides that lead to inhibition of DNA polymerase and chain termination. True or False?

A

True

46
Q 
Fludarabine falls under which antimetabolite class?
A) Folate inhibitors
B) Purine analogs
C) Adenosine analogs
D) Cytidine analogs
E) 5-Fluoropyrimidines
A

C - adenosine analogs

47
Q 
As a false nucleotide, which 3 things can fludarabine cause? 
A) Decrease DNA synthesis/repair
B) DNA break accumulation
C) Inhibit TPMT
D) Apoptosis/necrosis
A

A, B, D

48
Q 
What are the 2 dose-limiting toxicities for fludarabine?
A) Myelosuppression
B) Mucositis
C) Hand foot syndrome
D) Infectious complications
A

A & D

49
Q 
An example of RNR (Ribonucleotide Reductase) Inhibitor is which subclass and drug pair?
A) Purine analog; Hydroxyurea
B) 5-Fluoropyrimidine; Capecitabine
C) Folate inhibitor; MTX
D) Adenosine analog; Fludarabine
A

A - Hydroxyurea inhibits RNR and depletes deoxyribonucelotides – blocks growth of S phase

50
Q

Which of the following is a false characteristic of antimetabolites?
A) They are cytotoxic because they replace or deplete the normal nucleotides/building blocks needed for “metabolism” or cell growth via DNA/RNA replication
B) They are cell-cycle specific and are most effective during the S-phase of cell division.
C) Toxicities typically are a consequence of the interruption of cellular proliferation, especially in rapidly dividing cells.
D) It is best to take advantage of their cell-cycle specific nature by giving them in a bolus infusion.

A

D) It is best to give as a continuous or prolonged infusion because it means you can catch more cells that are, will be, and in transition to the S phase = killing more cells in total

51
Q

5-Fluorouracil cell-kill can be maximized by which of the following strategies?
A) Continuous infusion over several days to affect more cells, because it is non-cell cycle specific
B) Bolus dosing, to affect as many cells in S-phase as possible
C) Bolus dosing, to saturate as many cancer cells as possible
D) Continuous infusion over several days to affect more cells because it only affects cells in S phase

A

D

52
Q

Leucovorin rescue of MTX toxicity is dependent on
A) Expediting removal of MTX from the body
B) Breaking down extracellular MTX
C) Inhibiting MTX activity intracellularly
D) Replenishing tetrahydrofolate in the folate pathway

A

D

53
Q 
5-Fluorouracil and Capecitabine are part of which subclass of antimetabolites?
A) Folate inhibitors 
B) 5-Fluoropyrmidines
C) Cytidine analogs
D) Purine analogs/inhibitors
E) Adenosine analogs
A

B

54
Q 
Cytarabine, Gemcitabine, 5-Azacytidine, and Decitabine are part of which subclass of antimetabolites?
A) Folate inhibitors 
B) 5-Fluoropyrmidines
C) Cytidine analogs
D) Purine analogs/inhibitors
E) Adenosine analogs
A

C

55
Q 
6-Mercaptopurine, 6-Thioguanine, Azathioprine, and Hydroxyurea are part of which subclass of antimetabolites?
A) Folate inhibitors 
B) 5-Fluoropyrmidines
C) Cytidine analogs
D) Purine analogs/inhibitors
E) Adenosine analogs
A

D

56
Q 
Fludarabine, Cladribine, Clofarabine, and Pentostatin are part of which subclass of antimetabolites?
A) Folate inhibitors 
B) 5-Fluoropyrmidines
C) Cytidine analogs
D) Purine analogs/inhibitors
E) Adenosine analogs
A

E

Oncology (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions