Topoisomerase Inhibitors/ DRUGS

Question 1

Etoposide and Teniposide are _______________ inhibitors.

Answer 1

TOPOISOMERASE II INHIBITORS

Question 2

What’s the mechanism of Topoisomerase Inhibitors?

Answer 2

To relieve DNA supercoiling during DNA replication due to unwinding of the double helix (double strand breaks)

Question 3

Which drugs prevent religation of the double strand break induced by topoisomerase II?

Answer 3

ETOPOSIDE & TENIPOSIDE

Question 4

Topoisomerase inhibitors block the ____________ phase of the cell cycle (DNA synthesis)

Answer 4

S PHASE

Question 5

Topoisomerase inhibitors block the ________ phase of the cell cycle (double check and repair system)

Answer 5

G2 PHASE

Question 6

Etoposide and Teniposide treat many solid and hematological malignancies including…?

Answer 6

(e.g. testicular cancer, small cell lung cancer, Hodgkin and non-Hodgkin lymphoma)

Question 7

Topoisomerase II inhibitors can cause ?

Answer 7

IMMUNOSUPPRESSION

Question 8

Topoisomerase II inhibitors can cause ?

Answer 8

ALOPECIA

Question 9

Topoisomerase II inhibitors can cause?

Answer 9

MYELOSUPPRESSION

Question 10

What is the mechanism of action of TOPOTECAN and IRINOTECAN?

Answer 10

Inhibit topoisomerase I (single strand nick to relieve negative supercoiling)

Question 11

Topotecan treats _____________ cancer & _____________ cancer

Answer 11

CERVICAL & SMALL CELL LUNG

Question 12

Irinotecan treats ______________ cancer

Answer 12

COLON

Question 13

What are the toxicities (2) of the drugs topotecan and irinotecan?

Answer 13

• MYELOSUPPRESSION
• DIARRHEA

Question 14

With which drug use can late onset diarrhea that occurs 2-10 days after treatment can lead to major electrolyte imbalances and dehydration?

Answer 14

IRINOTECAN

Question 15

What is the dose-limiting toxicity for etoposide?

Answer 15

MYELOSUPPRESSION

Question 16

A 55-year-old woman with metastatic colon cancer is treated with a chemotherapeutic regimen that includes irinotecan, 5-fluorouracil, and leucovorin. His physician should also prescribe which of the following drugs used to treat the adverse gastrointestinal effects induced by this chemotherapeutic regimen?

A. Loperamide

B. Magnesium hydroxide

C. Pregabalin

D. Senna

Answer 16

LOPERAMIDE

Question 17

Which drug acts as a:

• stimulates Mu opiod receptors
• decrease interstitial motility
• increase colonic absorption of fluid

Answer 17

LOPERAMIDE

Question 18

A cancer cell exhibits resistance to etoposide. Further experimentation reveals that the cells are also resistant to teniposide but not to irinotecan or topotecan. Considering the mechanism of action of these drugs, which of the following is the most likely mechanism of resistance?

A. Increased expression of P-glycoprotein

B. Increased rate of DNA repair

C. Mutation in topoisomerase I

D. Mutation in topoisomerase II

Answer 18

D. Mutation in topoisomerase II

Question 19

ETOPOSIDE treats:

TENIPOSIDE treats:

IRINOTECAN treats:

TOPOTECAN treats:

Answer 19

ETOPOSIDE treats:

-testicular
-small cell lung cancer
-AML

TENIPOSIDE treats:

• acute lymphoblastic leukemia
• non-Hodgkin’s Lymphoma

IRINOTECAN treats: colon cancer

TOPOTECAN treats: cervical & ovarian cancer