Mechanisms Of Cancer Drugs

Question 1

What is the mechanism of action of Cyclophosphamide?

Answer 1

Alkylating agent - causes cross-linking in DNA

Cyclophosphamide is used in various chemotherapy regimens and is known for its effectiveness in treating certain cancers.

Question 2

What are the major adverse effects of Cyclophosphamide?

Answer 2

Haemorrhagic cystitis, myelosuppression, transitional cell carcinoma

Haemorrhagic cystitis is often dose-dependent and may be mitigated by hydration and mesna.

Question 3

How does Bleomycin work?

Answer 3

Degrades preformed DNA

Bleomycin is commonly used to treat testicular cancer and Hodgkin’s lymphoma.

Question 4

What is a significant adverse effect of Bleomycin?

Answer 4

Lung fibrosis

Lung toxicity can be dose-limiting and is a major concern during treatment.

Question 5

What is the mechanism of action of Anthracyclines like Doxorubicin?

Answer 5

Stabilizes DNA-topoisomerase II complex, inhibits DNA & RNA synthesis

Anthracyclines are widely used in various cancer therapies, but cardiotoxicity limits their use.

Question 6

What adverse effect is associated with Anthracyclines?

Answer 6

Cardiomyopathy

Regular monitoring of cardiac function is essential during therapy with anthracyclines.

Question 7

What is the mechanism of action of Methotrexate?

Answer 7

Inhibits dihydrofolate reductase and thymidylate synthesis

Methotrexate is used to treat various cancers and autoimmune diseases.

Question 8

List the major adverse effects of Methotrexate.

Answer 8

• Myelosuppression
• Mucositis
• Liver fibrosis
• Lung fibrosis

These effects necessitate careful monitoring and sometimes dose adjustments.

Question 9

What type of analogue is Fluorouracil (5-FU) and what is its mechanism of action?

Answer 9

Pyrimidine analogue inducing cell cycle arrest and apoptosis by blocking thymidylate synthase (works during S phase)

5-FU is commonly used in the treatment of colorectal cancer.

Question 10

What are the adverse effects of Fluorouracil (5-FU)?

Answer 10

Myelosuppression, mucositis, dermatitis

These side effects can significantly impact the patient’s quality of life.

Question 11

What is the mechanism of action of 6-mercaptopurine?

Answer 11

Purine analogue that is activated by HGPRTase, decreasing purine synthesis

6-mercaptopurine is used primarily in the treatment of leukemia.

Question 12

What adverse effect is commonly associated with 6-mercaptopurine?

Answer 12

Myelosuppression

Monitoring blood counts is crucial during treatment.

Question 13

What is the mechanism of action of Cytarabine?

Answer 13

Pyrimidine antagonist. Interferes with DNA synthesis specifically at the S-phase of the cell cycle and inhibits DNA polymerase

Cytarabine is often used in the treatment of acute myeloid leukemia.

Question 14

What are the adverse effects of Cytarabine?

Answer 14

Myelosuppression, ataxia

Ataxia is less common but can occur, particularly with high doses.

Question 15

What is the action of Vincristine and Vinblastine?

Answer 15

Inhibits formation of microtubules

These agents are used in various combination chemotherapy regimens.

Question 16

What are the adverse effects of Vincristine?

Answer 16

Peripheral neuropathy (reversible), paralytic ileus

Peripheral neuropathy can manifest as numbness and tingling in extremities.

Question 17

What is the main adverse effect of Vinblastine?

Answer 17

Myelosuppression

Vinblastine requires careful monitoring of blood counts.

Question 18

What is the mechanism of action of Docetaxel?

Answer 18

Prevents microtubule depolymerisation & disassembly, decreasing free tubulin

Docetaxel is used in breast, lung, and prostate cancers.

Question 19

What adverse effect is associated with Docetaxel?

Answer 19

Neutropaenia

Neutropaenia increases the risk of infections during treatment.

Question 20

What is the mechanism of action of Irinotecan?

Answer 20

Inhibits topoisomerase I which prevents relaxation of supercoiled DNA

Irinotecan is primarily used in colorectal cancer treatment.

Question 21

What are the adverse effects of Irinotecan?

Answer 21

Myelosuppression

This effect necessitates monitoring of blood counts.

Question 22

What is the mechanism of action of Cisplatin?

Answer 22

Causes cross-linking in DNA

Cisplatin is widely used in various solid tumors.

Question 23

List the major adverse effects of Cisplatin.

Answer 23

• Nephrotoxicity (the primary dose-limiting side effect)
• Ototoxicity
• Peripheral neuropathy
• Hypomagnesaemia

Hydration and nephroprotective agents are often used to mitigate nephrotoxicity.

Question 24

What is the mechanism of action of Hydroxyurea?

Answer 24

Inhibits ribonucleotide reductase, decreasing DNA synthesis

Hydroxyurea is used in myeloproliferative disorders and some cancers.