2.9 Other cytotoxic drugs

Question 1

What are the two reasons why cytotoxic drugs may not fit into a conventional chemothrapy class?

In a class of their own…

Answer 1

• Their own unique mode of action
• An unknown mode of action

Question 2

Name 3 other types of cytotoxic drugs which dont fit in a conventional chemotherapy classification?

Answer 2

• Asparaginase
• Arsenic trioxide
• Hydroxycarbamide

Question 3

What is the mode of action of Asparaginase?

Answer 3

Asparaginase is an enzyme that catalyzes the conversion of the amino acid asparagine into aspartic acid and ammonia.

Asparaginase is used as a medication in the treatment of certain types of leukemia, particularly acute lymphoblastic leukemia (ALL).

Asparaginase depletes the levels of asparagine in the blood and intracellular spaces, inhibiting the growth of cancer cells that rely on asparagine for protein synthesis.

Leading to cell death.

Question 4

Which type of patient might received Asparaginase?

Answer 4

This selective toxicity to cancer cells makes asparaginase an important component of chemotherapy regimens for ALL.

Question 5

What is the mode of action of arsenic trioxide?

Answer 5

Arsenic trioxide is believed to

• induce morphological cellular changes and DNA fragmentation.
• induce cellular differentiation/apoptosis
• growth inhibition
• degradation of the characteristic PML-RAR-alpha gene specific to promyelocytic leukaemia

Question 6

Which type of condition is this drug used in?

Answer 6

Arsenic trioxide is an essential drug in the management for acute promyelocytic leukaemia (APML)

Question 7

What is the mode of action of hydroxycarbamide

Previously known as hydroxyurea

Answer 7

Hydroxycarbamide
Inhibits the action of ribonucleoside diphosphate reductase.

Diphosphate reductase is responsible for catalyzing the conversion of ribonucleotides to deoxyribonucleotides, the building blocks of DNA.

Hydroxycarbamide also causes
* Cell cycle arrest in the S phase of the cell cycle.
* Induction of apoptosis
* modulation of fetal hemoglobin production in sickle cell disease.

Question 8

Which types of patients receive Hydroxycarbamide?

Previously known as hydroxyurea

Answer 8

• sickle cell disease
• myeloproliferative diseases