Intracellular Poisons: Alkylators Flashcards

1
Q

Leaving groups are

A

electrophiles that are happy to take pair of electrons

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2
Q

materials with electron density to spare

A

nucleophiles

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3
Q

Biologic molecules are loaded with ____________ that have ______ that react with electrophiles

A

Biologic molecules are loaded with Sulfur, Nitrogen and Oxygen atoms that have lone pairs of electrons that can react with Electrophiles:

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4
Q

Many drugs work by a mechanism involving

A

a highly reactive Electrophile which is generated (or unveiled) in a context that covalently (often irreversibly) alters a protein or nucleic acid.

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5
Q

Alkylation

A

X-R(3)

Nu comes in and kicks of x leaving Nu-R(3)

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6
Q

acylation

A

R1-C=O-x
Nu comes in and kicks out X
R1-C=O-nu

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7
Q

mustards

A

2 cl and a middle N or S

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8
Q

what do mustards like to attack and how

A

N(7) on guanine (-G-G-C-)

S or N get rid of Cl, reactive intermediate, and attack N(7) guanine = crosslink

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9
Q

N7 is the most important

A

nucleophilic sites on DNA

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10
Q

As usual, the electron rich stuff combines with the electron poor. In medicine, biomolecules (proteins, nucleic acids and glutathione) are ____________ and and drugs are the ________

A

As usual, the electron rich stuff combines with the electron poor. In medicine, biomolecules (proteins, nucleic acids and glutathione) are electron rich, and drugs are the electrophiles.

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11
Q

DNA is usually ________ on N(7) of Guanine and this leads to breakage ________

A

DNA is usually alkylated on N(7) of Guanine and this leads to breakage of the “glycosidic” bond (i.e. base—sugar).

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12
Q

_______ agents are more effective at creating lesions that are difficult to repair

A

bifunctional agents

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13
Q

5 important Alkylators

A
cyclophosphamide
Bendamustine
Temozolomide
Cisplatin
Carboplatin
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14
Q

Bendamustin
invented for
use for
SE

A

CLL
indolent B-cell malignanices
prolonged neutropenia in some patients

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15
Q
cyclophosphamide
invented for 
oxidized by
metabolism
used for
A

originally made for GI cancers
cyto P-450, ALDH (good TI)
hematologic malignancies (CHOP), Wilm’s, Breast cancer, Germ cell tumors, autoimmune disease

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16
Q

most potently immunosuppressive mustard

A

cyclophosphamide

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17
Q

long-term administration, especially orally, of cyclophosphamide is associated with

A

induction of hemorrhagic cystitis, bladder cancer and myelodysplasia (especially 5q-)

d/t acrolein being toxic to lining of bladder

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18
Q

what is a powerful inducer of G-CSF (and GM-CSF) and is often used to mobilize stem cells for collection by apheresis

A

cyclophosphamide

19
Q

what causes hemorrhagic cystitis, bladder cancer and myelodysplasia (especially 5q-)

A

long term admin of cyclophosphamide

20
Q

drug given w/ cyclophosphamide

A

Mercapto-ethylsulphonic acid, NA salt

MESNa

21
Q

MESNA

A

nucleophilic drug to soak up the acrolein, especially in the bladder.
(cyclophosphamide)

22
Q

More people get what than any other cytotoxic drug

A

cyclophosphamide

23
Q

what makes mustards useful for high-dose chemo w/ stem cell rescue

A

broad TI w/o obvious ceiling

24
Q

downsides of mustards

A

hemorrhagic cystitis, bladder cancer, myelodysplasia

25
important mustard drugs
cyclophosphamide bendamustine chlorambucil melphalan ifosfamide
26
important platinum drugs
cisplatin carboplatin oxaliplatin
27
consequences of DNA adducts
Inhibition of transcription Inhibition of DNA replication Induction of apoptosis
28
Cisplatin good for not very _____
indispensible for germ cell tumors | not very myelosuppressive
29
cisplatin toxicities
Damage to VIIIth nerve, and long sensory nerves Kidney damage, often irreversible, manifesting as electrolyte wasting and ATN Nausea and Vomiting
30
``` carboplatin good for not as active for pros myelosuppressive? ```
Great for solid tumors and salvage lymphoma regimes not as active as cisplatin in germ cell tumors, bladder, head and neck tumors - equivalent for Lung, gyn, and breast cancers much less neurotoxic, emetogenic, nephrotoxic than cisplatin quite myelosuppressive - thrombocytopenia
31
_____ is unmatched in broad-spectrum anti-cancer activity, and unmatched in toxicity among clinically useful anticancer drugs
Cisplatin
32
_______ is the most important toxicity (now that nephrotoxicity can be managed) of cisplatin
neuropathy
33
________ clearly has the most favorable therapeutic index of platinum drugs
carboplatin
34
_________ is active in GI adenocarcinomas, but is a very hard drug to take at extremes of latitude
oxaliplatin
35
progenitors of diazomethane
dacarbazine, procarbazine Temozolomide
36
Temozolomide is a prodrug for
MTIC
37
Temozolomide good for
CNS tumors
38
expression of ___ predicts poor clinical response to temozolomide
methylguanine methyltransferase (MGMT)
39
non-classical alkylators mostly used for
gliomas
40
Profound hematologic stem cell toxicity makes what useful for bone marrow transplant conditioning regimens
non-classical alkylators
41
The ________ are vessicants, extremely emetogenic and seldom used
carbazines
42
The dacarbazine-related prodrug ____________ is the current standard for glioma.
temozolomide
43
Expression of MGMT, or MMR deficiency, circumvent toxicity from the methylation from what drug
temozolomide