Principles of Chemotherapy

Question 1

what underlies immunity

Answer 1

the body’s ability to recognise and remove non-self material

Question 2

what underlies the action of anti-microbial drugs

Answer 2

ability of drugs tp recognise and destroy non-self cells

Question 3

what principle is chemotherapy based off

Answer 3

selective toxicity

Question 4

selective toxicity

Answer 4

drugs directed against targets that are involved in the function of abnormal cell/invading organism but aren’t required for host function

Question 5

chemotherapeutic index

Answer 5

lowest dose toxic to patient divided by the dose typically used for therapy

Question 6

different types of antimicrobial drugs

Answer 6

antibacterial drugs
anti fungal drugs
anti protozoan drugs
antihelminthic drugs

Question 7

antimicrobial drug

Answer 7

drug used to control bacteria, fungus, parasites, etc

Question 8

why are bacteria useful targets

Answer 8

because drugs show selectivity for isoforms

Question 9

trimethoprim chemistry

Answer 9

MW 290

Question 10

trimethorprim pharmacology

Answer 10

primary activity is via inhibition of dihydrofolate reductase
interaction between enzyme and substrate is via hydrogen bonding and antibiotic is a structural analogue of the substrate DHF

Question 11

trimethoprim physiology

Answer 11

dihydrofolate reductase DHFR is an essential enzyme
catalyses the reduction of dihydrofolate acid
to tetrahydrofolic acid
role of DHFR is related to the biosynthesis pathways of thymidylate and purines
inhibition leads to disruption of DNA replication
causes cell death

Question 12

trimethoprim clinical

Answer 12

often used in conjunction with sulfamethoxazole
treat infections: urinary, respiratory,ghastrointestinal tracts
also treat malaria and has anti proliferative effects (cancer)

Question 13

class 3 reactions

Answer 13

many are targets for selective toxicity

Question 14

what are class 3 reactions

Answer 14

pathways that convert small class 2 molecules into macromolecules

Question 15

what are class 2 reactions

Answer 15

pathways that utilise ATP and class 1 substrates to make small molecules

Question 16

cell wall synthesis

Answer 16

D-cycloserine
vancomycin
bacitracin
pincillins
cephalosporins
ephamycins

Question 17

cell wall integrity

Answer 17

beta-lactamases

Question 18

DNA synthesis

Answer 18

metronidazole

Question 19

DNA gyros

Answer 19

quinolones

Question 20

RNA polymerase

Answer 20

rifampicin

Question 21

phospholipid membranes

Answer 21

polymyxins

Question 22

two types of protein synthesis

Answer 22

50S and 30S

Question 23

30S inhibitors

Answer 23

tetracyclins
streptomycin
spectinomycin
kanamycin

Question 24

examples of beta lactam antibiotics

Answer 24

penicillins
cephalosporins
monobactams
carbapenems

Question 25

synthesis of cell walls as a target for antibacterial drugs

Answer 25

synthesis of N-acetylmuramic
acid-pentapeptide units
synthesis of peptidoglycan
polymers
cross-linking of peptidoglycan
chains

Question 26

PBP’s

Answer 26

penicillin binding proteins

Question 27

example of a PBP

Answer 27

transpeptidase enzyme that normally catalyses cross-linking of peptidoglycan polymers

Question 28

beta-lactam mechanism of action

Answer 28

structural analogs of D-ala-D-ala
covalently bind to PBPs (transpeptidase)
leads to inhibition of transpeptidation reaction essential for peptidoglycan synthesis

Question 29

what type of drug is trimethoprim

Answer 29

diaminopyrimidine

Question 30

ligand and target for trimethoprim §

Answer 30

10931
dihydrofolate reductase

Question 31

what type of drug is amoxicillin

Answer 31

beta lactam

Question 32

amoxicillin ligand and target

Answer 32

10865
bacterial penicillin binding protein

Question 33

chemistry of amoxicillin

Answer 33

MW 365

Question 34

pharmacology amoxicillin

Answer 34

primary activity inhibition of transpeptidases (specialised acyl serine transferases)
beta lactams mimic the d-ala-d-ala sequence and act as a false substrate for d-alanyl-d-alanine transpeptidases

Question 35

physiology amoxicillin

Answer 35

competitively inhibits penicillin binding proteins
leads to up regulation of autolytic enzymes and inhibition of cell wall synthesis
causes cell lysis

Question 36

cidal

Answer 36

causes cell lysis

Question 37

clinical amoxicillin

Answer 37

treatment of susceptible bacterial infections in: ear, nose, genitourinary tract, skin, skin structure and lower respiratory tract
used with omeprazole to treat helicobacter pylori

Question 38

ribosomal synthesis of proteins

Answer 38

potential target for antibacterial drugs

Question 39

aminoglycosides

Answer 39

targets 30S subunit gentamicin
16 S rRna
induces misreading, halt protein synthesis at high concentrations

Question 40

tetracycline

Answer 40

targets 30S subunit
16 S rRNA
block aminoayl tRNA binding

Question 41

macrolides

Answer 41

targets 50 S subunit
clarithromycin
23 S rRNA
inhibits translocation

Question 42

fusidic acid

Answer 42

50S subunit
23 S rRNA
inhibits translocation

Question 43

what type of drug is clarithromycin

Answer 43

macrolide

Question 44

chemistry of clarithromycin

Answer 44

MW 748
semisynthetic macrolide
derived from erythromycin

Question 45

ligand and target clarithromycin

Answer 45

10903
23S ribosomal RNA

Question 46

pharmacology clarithromycin

Answer 46

reversibly binds to 23S rRNA component of 50S ribosomal subunit of the ribosome
inhibits the translocation of aminoayl transfer-RNA
prevents peptide chain elongation

Question 47

physiology clarithromycin

Answer 47

inhibition of protein synthesis causes ell death
due to cell inability to produce new proteins