Topoisomerase Inhibitors Flashcards

1
Q

Cancer cells possess more of this enzyme involved in the replication and transcription than normal cells do

A

topoisomerase

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2
Q

these 2 anthracycline antibiotic are natural products of certain soil fungi

A

doxorubicin and daunorubicin

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3
Q

what is the mechanism of action of doxorubicin and daunorubicin

A

bind to DNA-interfering with the ability of nucleic acids to serve as a template during replication

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4
Q

doxorubicin and daunorubicin - their drug induced free radicals overwhelms which organ in the body

A

hearts

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5
Q

1-2 days after administration of daunorubicin and doxorubicin this will be seen in the urine

A

red urine

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6
Q

what occurs with each subsequent dose of daunorubicin and doxorubicin

A

it diminishes the hearts ability to withstand subsequent oxidant stress

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7
Q

explain the mechanism of how doxorubicin and daunorubicin free radicals affect the heart

A

free radicals overwhelm the hearts antioxidant defenses- leading to oxidation of critical cardiac proteins and membrane components (unsaturated free fatty acids)

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8
Q

daunorubicin clinical uses

A

acute lymphocytic and myelocytic leukemia

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9
Q

doxorubicin clinical uses

A
metastatic adenocarcinoma of the breast
carcinoma of the bladder
bronchogenic carcinoma
metastatic thyroid carcinoma
oat cell carcinoma
osteogenic carcinoma
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10
Q

side effects of daunorubicin and doxorubicin

A

cardiomyopathy and myelosuppression

stomatitis, gastrointestinal disturbances and alopecia are common side effects

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11
Q

if cumulative dose of doxorubicin is less than 400mg/m -what percent of patients develop congestive heart failure

A

3%

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12
Q

if cumulative dose of doxorubicin is 700mg/m what percent of patients develop congestive heart failure

A

18%

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13
Q

prior radiation or previous treatment of which drug can increase risk of cardiomyopathy

A

cyclophosphamide

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14
Q

2 months after cessation of treatment with doxorubicin “this” has been described during general anesthesia

A

acute left ventricular failure

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15
Q

describe some characteristics of the acute form of cardiomyopathy that can occur with doxorubicin

A
st - t changes
decrease QRS voltage
PVC's
SVT
cardiac conduction abnormalities
left axis deviation 
acute REVERSIBLE decrease in the ef within 24hrs after a single dose
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16
Q

what dose levels can the acute form of cardiomyopathy

A

ALL dose levels

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17
Q

describe some characteristics of the insidious(gradual) onset of cardiomyopathy

A

dry nonproductive cough-suggesting bronchitis

rapidly progressive heart failure-unresponsive to inotropic drugs and mechanical ventricular assistance.

18
Q

the insidious onset of cardiomyopathy is fatal how many weeks after onset of symptoms in 60% of patients

A

3 weeks!

19
Q

are there predictive test to determine early recognition of impending cardiomyopathy

A

no

20
Q

what is the free radical scavenger that protects the heart from doxorubicin-associated damage

A

dexrazoxane

21
Q

increased plasma concentrations of ____reflect drug induced injury to myocardial cells

A

troponin T

22
Q

what is the clinical use of dactinomycin

A

wilms tumor in children

rhabdomyosarcoma

23
Q

how does dactinomycin work

A

binds to DNA -RNA polymerase and transcription of the DNA molecule is blocked.

24
Q

dactinomycin can be used to inhibit immunologic responses as with what situation

A

organ transplant

25
Q

side effects of dactinomycin

A

nausea, vomiting, myelosuppression manifestation as pancytopenia

26
Q

bleomycin moa

A

produces free radicals which create DNA breaks

27
Q

bleomycin is administered IV and high concentrations occur in what two spots

A

skin and lungs

28
Q

bleomycin in combination with vinblastine is used to treat

A

testicular carcinoma

29
Q

what is bleomycin useful in the palliative treatment of

A

squamous cell carcinoma of the head, neck, esophagus, skin, and genitourinary tract

30
Q

what are the MOST COMMON side effects of bleomycin

A

mucutaneous reactions, stomatitis, alopecia, pruritus, erythema, hyperpigmentation.

31
Q

what does bleomycin cause for myelosuppression

A

MINIMAL myelosuppression

32
Q

what three things seen during an acute reaction in patients with lymphoma receiving bleomycin

A

hyperthermia
hypotension
hypoventilation

33
Q

what is the most serious side effects of bleomycin

A

dose related pulmonary toxicity

34
Q

what inactivates bleomycin- which is deficient in lung tissue

A

hydrolase enzyme

35
Q

what are the first signs of pulmonary toxicity from bleomycin

A

cough, dyspnea, basilar rales

36
Q

name the 8 risk factors for development of chemotherapy-induced pulmonary toxicity

A
total drug dose
age
concurrent or prior chest radiation
oxygen therapy
combination chemotherapy
preexisting pulmonary disease
genetic predisposition
cigarette smoking
37
Q

what is the recommended inhaled oxygen concentrations for bleomycin treated patients

A

less than 30%

38
Q

some reports state that oxygen concentrations greater than 30% can be harmful how many many after last dose of bleomycin

A

6-12mo

39
Q

does corticosteroid pretreatment in patients whom have a greater risk of needing more than 30% oxygen prove helpful?

A

not confirmed

40
Q

how do we fluid replace patients with bleomycin treatment

A

give colloids over crystalloids.