Chemotherapy Flashcards

1
Q

Beta lactams (penicillin)

A

Ring is similar to D-ala-D-ala
Forms covalent bond with transpeptidase but doesn’t liberate it
Only bactericidal in proliferating cells

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2
Q

Vancomycin

A

Cup fits around D-ala-D-ala forming 5 H bonds and causing steric hinderance for transglycosylation

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3
Q

Fosfomycin

A

PEP analogue

Inhibits pyruvile transferase (For making NAM)

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4
Q

Cycloserine

A

Inhibits synthesis and linking of D-ala

Must cross cell membrane to do this in cytoplasm

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5
Q

Bacitracin

A

Binds bactoprenol monophosphate (membrane carrier) to deplete cycle of lipid career

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6
Q

Valinomycin

A

Makes ion channel to dissipate PMF via K+ movement

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7
Q

Polymyxin antibiotics

A

Bind gram -ve envelop to make it leaky

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8
Q

Tetracyclines

A

Bind 16S rRNA in 30S
Inhibit aminoacyl tRNA from entering A site
Bacteriostatic

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9
Q

Aminoglycosides (streptomycin, gentamicin)

A

Binds 30S; freezes pre-imitation complex so bacteriostatic

+ causes mRNA misreading to make toxic peptides; bactericidal

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10
Q

Erythromycin

A

Binds 50S at exit tunnel to stop synthesis

Bacteriostatic (mostly)

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11
Q

Chloramphenicol

A

binds 50S to stop peptidyl transferase; time critical infections only as very toxic

NB: can’t use with erythromycin as they have overlapping binding sites

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12
Q

Fusidic acid

A

inhibits elongation factor G

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13
Q

Fluoroquinolones (ciprofloxacin for anthrax, Levofloxin for strep pneumonia)

A

Target GyrA and B to cause bactericidal DNA fragmentation

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14
Q

Rifampicin

A

Blocks elongation of RNA at initiation stage (via binding beta subunit of DNA dependent RNA pol)
Used for TB

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15
Q

Aminocuomanis and Nalidixic acid

A

Inhibit DNA gyrase II via Gyrus B

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16
Q

Daunomycin

A

Intercalates between nucleases to increase DNA length to cause local unwinding

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17
Q

Bleomycin

A

Intercalated in DNA and if binding reduced metals can react to give superoxide to cleave DNA

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18
Q

Mitomycin C

A

alkylating; cross links between guanines

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19
Q

Sulfamethoxadole

A

inhibits DHPS in folate synthesis

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20
Q

Trimethoprim

A

inhibits DHFR in folate synthesis

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21
Q

Amphotericin B

A

makes ion channels in ergosterol membranes

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22
Q

Micanozol

A

inhibits ergosterol biosynthesis

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23
Q

Chloroquinone

A

inhibits detoxification of haem in malaria so get lots of ROS

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24
Q

Artemisinin

A

anti-malaria

Makes ROS

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25
Q

Sulfadoxine

A

inhibits DHPS (malaria)

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26
Q

Pyrimethamine

A

inhibits DHFR

27
Q

Melarsoprol

A

anti-trypanosomal
Actively accumulates
Inhibits ATP synthesis enzymes

28
Q

Amantidine/Rimantidine

A

Binds HA to prevent viral and endosomal membrane fusion
+ blocks M2 to prevent acidifcation

CHECK WHICH

29
Q

Ribavirin

A

Guanosine analogue
Inhibits initiation and elongation of mRNA

For hepatitis C

30
Q

Zanamivir (Relenza)

A

Sialic acid analogue to inhibits NA (early stages)

31
Q

Tamiflu (oseltamivir)

A

Inhibits NA

32
Q

Aciclovir

A

Guanosine analogue that causes chain termination
Prodrug
Interacts with viral DNA pol most
ANti-herpes

33
Q

Foscarnet (anti-herpes)

A

pyrophosphate analogue preventing addition of new nucleotides by binding viral DNA pol

34
Q

AZT, Zidovudine

A

thymidine analogue that causes chain termination

anti-HIV

35
Q

Saquinavir/Ritonavir

A

Blocks HIV protease

36
Q

Enfurvirtide

A

Inhibits HIV viral fusion

37
Q

1

A

1

38
Q

Nitrogen mustards (cyclophosphamide)

A

Cross links guanine in DNA
Anti-cancer
Metabolised by cytP450 to active mustard form

39
Q

Melphalam

A

Nitrogen mustard that is actively accumulated in melanomas

40
Q

Nitrosureas; Carmustin, Lomustin

A

Cross link DNA between guanines

Can cross BBB so used for brain tumours

41
Q

Cis-platin

A

Reacts with adjacent guanines in the same strand to cause cross links, bending DNA and changing minor groove

42
Q

Anthracyclins; doxorubicin, duanomycin, antimycin D

A

Intercalate in DNA, causing unwinding and oxidative DNA damage and fragmentation

43
Q

Mitoxantrone

A

Less toxic anthracyclin analogue

44
Q

Methotrexate

A

Folic acid analogue to inhibit DHFR

can provide folinic acid to help non cancerous cells survive

45
Q

5-flourouracil

A

Pyrimidine analogue to inhibit thymidylate synthase
Inhibits DNA synthesis
Anti-neoplastic

46
Q

Captothecins

A

Inhibiting type 1 topoisomerase

47
Q

Mitoxantrone, Antracycline, Etoposides

A

Inhibit type 2 topoisomerase

48
Q

Vinca alkaloids (vinblastine, vincristine)

A

Bind tubulin dimers to cause microtubule dissociation

49
Q

Taxol

A

Binds microtubules to stabilise so they grow

50
Q

Tamoxifen

A

Antagonises oestrogen receptor

51
Q

Anastrazole

A

Blocks aromatase enzyme used to synthesis oestrogens

For use in post-menopausal women

52
Q

Flutamide

A

Competitively inhibits androgen receptor for prostate cancer

53
Q

Goserelin

A

Agonist of GnRH receptor; acts via desensitisation to reduces testosterone production

54
Q

Prenisole

A

Converted to prednisone which agonists glucocorticoid receptor to inhibit lymphocytic growth in lymphocytic cancer

55
Q

Cetuximab

A

Binds EGFR for colorectal cancer

56
Q

Retuximab

A

Binds CD20 receptor to cause B cell lysis

57
Q

Imantinib

A

Inhibits BCr-ABl and c-kit in chronic myeloid leukaemia

58
Q

Methicillin resistance

A

MecA encodes new transpeptidase/transglycosylase with lower affinity for beta lactams
Fem genes generate Gly5 as cross link which is now better substrate

DONT NEED BOTH GENES FOR RESISTANCE

59
Q

Vancomycin resistance

A

Van genes; change to D-ala-D-lac

Target modification

60
Q

Beta lactam resistance

A

Beta lacatamase activity (blocked by clavulanic acid)

61
Q

Aminoglycoside (tetracycline) resistance

A

TetA proton drug anti porter used to pump out tetracycline

PSeudomonas aeruginosa

62
Q

Fluconazole resistance

A

Changes in ergosterol biosynthesis

63
Q

Multiple drug resistance

A

Mar regulon

P glycoprotein (transporter)