Antimetabolites: Mechanisms of Action and Clinical Applications

Question 1

Which of the following are the most common adverse effects associated with methotrexate treatment?

Accepted Answer

Myelosuppression, gastrointestinal toxicity, hepatotoxicity, and nephrotoxicity

Answer

Hypertension, elevated blood sugar, high cholesterol, and weight gain

Answer

Slow heart rate, low blood pressure, irregular heartbeat, and heart failure

Answer

Seizures, tremors, hallucinations, and loss of touch with reality

Question 2

The primary mechanism of action for antimetabolites is to:

Accepted Answer

Inhibit DNA synthesis

Answer

Interfere with mitosis

Answer

Block cell signaling pathways

Answer

Damage cell membranes

Question 3

A common clinical application for antimetabolites is:

Accepted Answer

Treating leukemia

Answer

Managing hypertension

Answer

Reversing antibiotic resistance

Answer

Preventing blood clots

Question 4

Methotrexate is classified as a:

Accepted Answer

Folate antagonist

Answer

Purine analog

Answer

Pyrimidine analog

Answer

Nucleotide reductase inhibitor

Question 5

The primary adverse effect associated with antimetabolites is:

Accepted Answer

Myelosuppression

Answer

Neurotoxicity

Answer

Gastrointestinal upset

Answer

Cardiotoxicity

Question 6

Aspirin is NOT an antimetabolite used in cancer chemotherapy because it is:

Accepted Answer

A non-steroidal anti-inflammatory drug

Answer

A folate antagonist

Answer

A purine analog

Answer

A pyrimidine analog

Question 7

The primary target of antimetabolites in cancer cells is:

Accepted Answer

DNA polymerase

Answer

RNA polymerase

Answer

Protein synthesis machinery

Answer

Cell membrane receptors

Question 8

A unique characteristic of purine analogs is that they:

Accepted Answer

Are metabolized to produce active nucleotides

Answer

Inhibit thymidine synthetase

Answer

Cause megaloblastic anemia

Answer

Are used to treat gout

Question 9

The difference between folate antagonists and nucleoside analogs is that:

Accepted Answer

Folate antagonists inhibit folate metabolism, while nucleoside analogs are incorporated into DNA

Answer

Folate antagonists are more toxic, while nucleoside analogs have a narrower therapeutic index

Answer

Folate antagonists are used in leukemia, while nucleoside analogs are used in solid tumors

Answer

Folate antagonists are natural products, while nucleoside analogs are synthetic

Question 10

When administering methotrexate, which nursing interventions are essential?

Accepted Answer

Monitor for signs of infection

Accepted Answer

Ensure adequate hydration

Accepted Answer

Administer folinic acid rescue as prescribed

Answer

Withhold the drug if the patient has a history of liver disease

Question 11

Antimetabolites primarily exert their cytotoxic effects by:

Accepted Answer

Interfering with DNA synthesis through the incorporation of incorrect nucleotides.

Answer

Inhibiting cell division by disrupting mitotic spindles.

Answer

Inducing apoptosis by activating death receptors.

Answer

Stimulating the immune system to recognize and destroy cancer cells.

Question 12

Which of the following is NOT a common clinical application of antimetabolites?

Accepted Answer

HIV infection

Answer

Acute myeloid leukemia

Answer

Breast cancer

Answer

Colorectal cancer

Question 13

Which antimetabolite is primarily used in the treatment of chronic myeloid leukemia?

Accepted Answer

Imatinib

Answer

Methotrexate

Answer

5-Fluorouracil

Answer

Cladribine

Question 14

The most common laboratory test used to monitor myelosuppression in patients receiving antimetabolites is:

Accepted Answer

Complete blood count

Answer

Liver function tests

Answer

Electrolyte panel

Answer

Urinalysis

Question 15

The preferred route of administration for most antimetabolites is:

Accepted Answer

Intravenous

Answer

Oral

Answer

Intramuscular

Answer

Subcutaneous

Question 16

Which of the following describes the cell cycle phase where DNA replication occurs?

Accepted Answer

S phase

Answer

G1 phase

Answer

G2 phase

Answer

M phase

Question 17

Which drug is a purine analog?

Accepted Answer

6-mercaptopurine

Answer

Methotrexate

Answer

5-fluorouracil

Answer

Cytarabine

Question 18

Identify the drug that属于 pyrimidine analogs?

Accepted Answer

5-fluorouracil

Answer

Methotrexate

Answer

6-mercaptopurine

Answer

Cytarabine

Question 19

Accurately describe the primary mechanism of action of antimetabolites.

Accepted Answer

Inhibiting cell division by interfering with DNA or RNA synthesis

Answer

Promoting cell death by inducing apoptosis

Answer

Enhancing the immune system's ability to recognize and attack cancer cells

Answer

Reducing blood flow to tumors, causing them to shrink

Question 20

Indicate a clinical application of methotrexate.

Accepted Answer

Treating acute lymphoblastic leukemia

Answer

Managing rheumatoid arthritis

Answer

Preventing organ rejection after transplantation

Answer

Controlling seizures in epilepsy

Question 21

Which adverse effect is commonly associated with fluorouracil therapy?

Accepted Answer

Gastrointestinal toxicity (e.g., nausea, vomiting)

Answer

Myelosuppression

Answer

Renal impairment

Answer

Neurotoxicity

Question 22

Which type of cancer is commonly treated with a combination of methotrexate, vincristine, and actinomycin D?

Accepted Answer

Acute lymphoblastic leukemia

Answer

Hodgkin's lymphoma

Answer

Breast cancer

Answer

Lung cancer

Question 23

How does methotrexate work as an antimetabolite?

Accepted Answer

Blocks dihydrofolate reductase, reducing thymidine and purine production.

Answer

Inhibits thymidylate synthase, decreasing thymidine production.

Answer

Blocks DNA polymerase, reducing DNA synthesis.

Answer

Inhibits topoisomerase II, causing DNA damage and cell death.

Question 24

Which of the following is NOT a mechanism of action of antimetabolites?

Accepted Answer

Promotion of cell growth

Answer

Inhibition of DNA synthesis

Answer

Interference with RNA transcription

Answer

Inhibition of DNA repair

Question 25

Which of the following antimetabolites is a thymidine analog?

Accepted Answer

Capecitabine

Answer

Methotrexate

Answer

5-Fluorouracil

Answer

Gemcitabine

Question 26

Which of the following best describes the primary mechanism of action of antimetabolites?

Accepted Answer

Inhibition of DNA synthesis through interference with thymidine metabolism

Answer

Inhibition of RNA synthesis by disrupting purine synthesis

Answer

Induction of cell death through DNA cross-linking

Answer

Depletion of folate through dihydrofolate reductase inhibition

Question 27

Which of the following is a common clinical application of antimetabolites?

Accepted Answer

Management of solid tumors, such as breast and lung cancer

Answer

Treatment of autoimmune conditions, such as rheumatoid arthritis

Answer

Prevention of organ transplant rejection

Answer

Treatment of viral infections

Question 28

Which of the following antimetabolites is primarily used as a folic acid antagonist?

Accepted Answer

Methotrexate

Answer

5-Fluorouracil

Answer

Cytosine arabinoside

Answer

Mercaptopurine

Question 29

What is the most common route of administration for antimetabolites?

Accepted Answer

Intravenous

Answer

Oral

Answer

Intramuscular

Answer

Subcutaneous

Question 30

Why is it important to monitor blood counts when administering antimetabolites?

Accepted Answer

To detect potential myelosuppression

Answer

To monitor for hypertension

Answer

To assess for hepatotoxicity

Answer

To prevent electrolyte imbalances

Question 31

Which of the following factors is NOT considered when selecting an antimetabolite for cancer therapy?

Accepted Answer

Patient financial status

Answer

Tumor type

Answer

Patient age

Answer

Treatment efficacy

Question 32

During which phase of the cell cycle are antimetabolites most effective in inhibiting cell growth?

Accepted Answer

S phase, when DNA synthesis occurs

Answer

M phase, when cell division occurs

Answer

Antimetabolites are equally effective during all stages of the cell cycle

Question 33

Which of the following is a potential drug interaction involving antimetabolites that can increase the risk of bleeding?

Accepted Answer

Antimetabolites can interact with anticoagulants like warfarin.

Answer

Antibiotics can reduce the risk of infections when used with antimetabolites.

Answer

Antimetabolites do not interact with other medications.

Answer

None of the above.

Question 34

Which of the following is NOT a mechanism of action for antimetabolites?

Accepted Answer

Enhancement of cell division

Answer

Inhibition of DNA synthesis

Answer

Interference with RNA transcription

Answer

Inhibition of folate metabolism

Question 35

Which of the following antimetabolites is a purine analog?

Accepted Answer

Mercaptopurine

Answer

5-Fluorouracil

Answer

Methotrexate

Answer

Cytarabine

Question 36

Which of the following is a major clinical application of antimetabolites?

Accepted Answer

Chemotherapy for cancer

Answer

Treatment of bacterial infections

Answer

Management of autoimmune diseases

Answer

Prevention of cardiovascular events

Question 37

Which of the following accurately describes the primary mechanism of action of antimetabolites?

Accepted Answer

They interfere with DNA and RNA synthesis by mimicking and replacing normal precursors, inhibiting their incorporation into nucleic acids.

Answer

They alkylate DNA, causing irreparable damage and inhibiting cell division.

Answer

They disrupt cell membrane synthesis, leading to cell lysis and death.

Answer

They prevent protein synthesis by binding to the ribosome, blocking the attachment of amino acids.

Question 38

Which of the following is an example of a purine antimetabolite?

Accepted Answer

6-Mercaptopurine

Answer

Cytarabine

Answer

5-Fluorouracil

Answer

Hydroxyurea

Question 39

What is the primary clinical application of antimetabolites?

Accepted Answer

Cancer chemotherapy

Answer

Immunosuppression

Answer

Antibacterial treatment

Answer

Antiviral treatment

Question 40

Which of the following side effects is a common concern associated with methotrexate therapy?

Accepted Answer

Myelosuppression, particularly affecting rapidly dividing cells in the bone marrow.

Answer

Cardiotoxicity causing heart muscle damage and arrhythmias.

Answer

Nephrotoxicity due to crystallization in the renal tubules.

Answer

Hepatotoxicity leading to liver damage and impaired function.

Question 41

What is the specific antidote used to treat methotrexate toxicity?

Accepted Answer

Leucovorin

Answer

Activated charcoal, used to absorb drugs from the gastrointestinal tract.

Answer

Amifostine, a protective agent used during radiation therapy.

Answer

N-acetylcysteine, an antidote for acetaminophen overdose.

Question 42

Which of the following accurately describes the primary mechanism of action of antimetabolites?

Accepted Answer

They interfere with DNA and RNA synthesis by competing with their normal precursors.

Answer

They directly damage DNA strands, causing cell death.

Answer

They target specific proteins involved in cell division.

Question 43

Identify the antimetabolite commonly used in the treatment of leukemia:

Accepted Answer

Methotrexate

Answer

Doxorubicin

Answer

Trastuzumab

Answer

Cisplatin

Question 44

Which type of cancer is most susceptible to treatment with antimetabolites?

Accepted Answer

Acute lymphoblastic leukemia

Answer

Glioblastoma

Answer

Lung adenocarcinoma

Answer

Colorectal cancer

Question 45

To minimize the risk of myelosuppression during antimetabolite therapy, what essential nursing intervention should be implemented?

Accepted Answer

Regular monitoring of blood counts

Answer

Administration of antibiotics

Answer

Patient education on symptom management

Answer

Use of growth factors

Question 46

Antimetabolites are most effective against cancer cells that are:

Accepted Answer

Rapidly dividing

Answer

Metastatic

Answer

Slow-growing

Answer

Non-dividing

Question 47

What is the primary objective of combination chemotherapy regimens that include antimetabolites?

Accepted Answer

To enhance efficacy and reduce the emergence of resistance

Answer

To improve patient comfort

Answer

To reduce the duration of treatment

Answer

To decrease side effects

Question 48

A patient is receiving methotrexate for rheumatoid arthritis. What is the MOST important patient education instruction regarding alcohol consumption?

Accepted Answer

Avoid consuming alcohol while taking this medication.

Answer

Alcohol consumption is safe in moderation.

Answer

Limit alcohol intake to one drink per day.

Answer

Alcohol may enhance the therapeutic effects of methotrexate.

Question 49

Which antimetabolite inhibits dihydrofolate reductase, blocking the synthesis of tetrahydrofolic acid?

Accepted Answer

Methotrexate

Answer

5-Fluorouracil

Answer

Cytarabine

Answer

Mercaptopurine

Question 50

A patient receiving chemotherapy with 5-fluorouracil (5-FU) develops severe diarrhea. What is the likely cause of this side effect?

Accepted Answer

Gastrointestinal toxicity

Answer

Neurotoxicity

Answer

Pulmonary toxicity

Answer

Cardiotoxicity

Question 51

During which phase of the cell cycle are antimetabolites most effective?

Accepted Answer

S phase

Answer

G2 phase

Answer

G1 phase

Answer

M phase

Question 52

Which of the following is NOT a common side effect of antimetabolite therapy?

Accepted Answer

Hypertension

Answer

Nausea and vomiting

Answer

Mucositis

Answer

Bone marrow suppression

Question 53

Leucovorin is sometimes administered after high-dose methotrexate therapy. What is its primary purpose?

Accepted Answer

Reduce the risk of methotrexate toxicity

Answer

Enhance the cytotoxic effects of methotrexate

Answer

Prevent tumor lysis syndrome

Answer

Stimulate bone marrow recovery

Question 54

Which antimetabolite is commonly used in combination therapy for breast cancer?

Accepted Answer

Fluorouracil

Answer

Pralatrexate

Answer

Nelarabine

Answer

Azathioprine

Question 55

When monitoring patients receiving antimetabolite therapy, which laboratory value is most important to observe?

Accepted Answer

Decreased white blood cell count

Answer

Increased serum creatinine

Answer

Increased platelet count

Answer

Decreased liver enzymes

Question 56

Which statement BEST describes the mechanism of action of antimetabolites?

Accepted Answer

They interfere with DNA and RNA synthesis, preventing cell division.

Answer

They directly damage DNA strands, leading to cell death.

Answer

They disrupt microtubule formation, preventing cell mitosis.

Answer

They inhibit topoisomerase enzymes, preventing DNA replication.