Alkylating chemotherapeutic agents used in cancer treatment act by?

Appeared in: SCTIMST Staff Nurse - 2015 (Set-A)

Explanation

Alkylating agents exert their cytotoxic effect by directly altering the chemical structure of DNA within the cell nucleus.
They form covalent bonds and cross-links in the DNA strands, which prevents the DNA from unwinding.
This inhibition of DNA replication and transcription ultimately triggers apoptosis, or programmed cell death, in the cancer cell.
This mechanism is not specific to any particular phase of the cell cycle, meaning these drugs can kill cells at any point in their life cycle.

Option B: Destroying messenger RNA (mRNA) is not the primary mechanism of alkylating agents. Their main target is DNA.
Option C: This describes the mechanism of hormonal therapies, not alkylating agents. Hormonal agents interfere with the hormones that some cancers need to grow.
Option D: While DNA damage ultimately interrupts cellular metabolism, this option is too general. The specific primary action of alkylating agents is DNA damage. This option better describes another class of chemotherapy.

Clinical Relevance

Nursing practice connection: Knowing Mechanism of Action of Alkylating Agents helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Understanding the mechanism of alkylating agents helps nurses anticipate and manage their specific side effects, which are often related to damage in rapidly dividing normal cells (e.g., bone marrow, hair follicles, GI tract).
Key nursing interventions include monitoring complete blood counts (CBC) for myelosuppression, administering antiemetics for nausea, and providing patient education on alopecia and infection risk.
A critical nursing responsibility for drugs like cyclophosphamide and ifosfamide is to ensure adequate hydration and administer a bladder-protectant agent like mesna to prevent hemorrhagic cystitis, a severe side effect caused by a toxic metabolite (acrolein).

How to Approach the Question

First, identify the core subject of the question: 'Alkylating chemotherapeutic agents'.
Next, analyze the question's prompt, which asks for the 'mechanism of action' ('act by?'). This is a factual recall question about pharmacology.
Evaluate each option based on your knowledge of chemotherapy classes.
Option A: 'Damaging DNA' is the hallmark of alkylating agents. This is a strong candidate.
Option B: 'Destroying mRNA' is not the primary target; DNA is.
Option C: 'Hormonal imbalance' relates to hormonal therapies, a different class.

Concept Tested & Keywords

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E6 Pharmacology Nursing Lilley 11e Part 3 p. 99-101

E6 Pharmacology Katzung 16e pp. 1482-1484, 1484-1486

Practise the full SCTIMST Staff Nurse - 2015 (Set-A)

Attempt every question from this paper in a timed mock, then review the full solution for each one.