Topoisomerase 1 Inhibitors

Question 1

MOA of top 2 inhibitors

Answer 1

BLOCK the coiling and uncoiling of the dsDNA helix during the S PHASE of the cell cycle

Question 2

List topoisomerase 1 drug(s)

Answer 2

Irinotecan
Topotecan

Question 3

What is the safety concerns for topoisomerase 1 inhibitors

Answer 3

1. ACUTE DIARRHEA (during or immediately after infusion)
2. CHOLINERGIC sx’s

Question 4

Acute vs Delayed diarrhea

Answer 4

1. Acute (during or immediately after infusion)
2. Delayed > 24 H after infusion

Question 5

What anticholinergic is used in both prevention and treatment of acute diarrhea

Answer 5

Atropine

Question 6

what tx is used for delayed diarrhea

Answer 6

1. LOPERAMIDE (antidiarrheal)
2. symptomatic care for BOTH (hydration, electrolyte replacement)