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MODA List 1 > 2-2 Van Veen > Flashcards

2-2 Van Veen Flashcards

1
Q

Aciclovir

A

Antiviral Purine analogue (guanine)
Prodrug - only monophosphorylated by
viral thymidine kinase in infected cells
Cellular enzymes convert to acyclovir-TP
Preferentially interacts with viral DNA
polymerase (30 x)
Competitive substrate, and is incorporated in viral DNA, causing termination of DNA replication (no 3’OH)
Resistance in Herpes virus due to change in specificity of viral thymidine kinase

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2
Q

Amantadine

A

Antiviral for Influenza A
Early - Acts on M2 proton channel involved in nucleocaspid uncoating
High affinity binding site at low pH where it blocks proton conduction
Late - interfere with hemagglutinin processing
Acidification of interior of virion is required for hemagglutinin-mediated membrane fusion and release into cytosol

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3
Q

Amoxicillin

A

B-lactam Antibiotic
Blocks cell wall peptidoglycan-crosslinking transpeptidase by covalent and irreversible binding as a pseudo-substrate
Forms a slowly hydrolysing covalent acyl enzyme intermediate

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4
Q

Amphotericin B

A

Polyene antibiotic - antifungal and antiparasitic
Low degree of selective toxicity and low therapeutic index, little selectivity and quite toxic
Target ergosterol in fungal (and leishmania protozoa) cell membranes, forming pores

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5
Q

Artemisinin

A

Antimalarial
Prodrug of dihydroartemisinin
Generates highly reactive organic free radicals
Short but rapid action
Also prevent development of oocyst in mosquito

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6
Q

Bacitracin

A

Cyclic peptide antibiotic
Forms a very tight complex with Mg2+ and bactoprenol pyrophosphate, inhibits dephosphorylation to bactoprenol phosphate so inhibits regeneration of the lipid carrier (for NAM-NAG unit), and hence, the biosynthesis of PG
It is active against Gram-positive bacteria.

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7
Q

Bevacizumab

A

A humanised monoclonal antibody that binds and inhibits the human VEGF
Anti-angiogenic - can interfere with wound healing
anti-VEGF

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8
Q

Cephalosporin

A

B-lactam antibiotic with B-lactam and thiazolidine ring
B-lactamases result in hydrolytic ring opening and deactivation
Rotating use of antibiotics improves efficacy and reduces emergence of resistance

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9
Q

Chloramphenicol

A

Bacteriostatic broad spectrum antibiotic
Interfere with protein biosynthesis
Target 50S ribosomal subunit
Blocks amino-acyl tRNA interaction with A site of peptidyl transferase centre
Resistance by inactivating acetyltransferases
Can cause bone marrow suppression

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10
Q

Chloroquine

A

Antimalarial
Accumulates inside food vacuole
(Plasmodium use hemaglobin as N source. Toxic heme polymerised to non-toxic hemozoin in food vacuole. )
Inhibit heme polymerization reaction in plasmodium
Drug resistance by exclusion of drug from site of action
Efflux by CRT (chloroquine resistance transporter)

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11
Q

Ciprofloxacin

A

Synthetic fluoroquinolone antibiotic
Activity against gram +ve and -ve bacteria
inhibits type II DNA topoisomerases (DNA gyrase and topo IV)
Inhibits changes in supercoiling in replication and gene expression
Used against Bacillus anthracis in anthrax and Pseudomonas infections - oral therapy preferred

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12
Q

Cisplatin

A

Anti-cancer
Platinum compound that binds directly to DNA to prevent replication and expression
Only active in cis form
Cross-linking agent in DNA
React at N7 of guanine and adenine
Intrastrand cross-link of 2 neighbouring guanines pGpG
Major bending of duplex to major groove
Inhibit DNA polymerase and DNA replication
Resistance - cells have higher levels of DNA repair enzymes
Used IV
Renal toxicity and bone marrow suppression

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13
Q

Clavulanate

A

Suicide substrate for lactamase

Forms a slowly hydrolysing acyl enzyme intermediate

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14
Q

Augmentin

A

Amoxicillin + Clavulanate

B-lactam antibiotic + B-lactamase inhibitor

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15
Q

Co-trimoxazole

A

Antibiotic acting as anti-metabolite
Trimethoprim + sulfamethoxazole
Both block a step in biosynthesis of folic acid
Work together synergistically

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16
Q

Cyclophosphamide

A

Anti-cancer
Nitrogen mustard - covalently link alkyl group to chemical moieties in nucleic acids and proteins
Broad application in cancer chemotherapy
Absorbed well orally and do not accumulate in a particular tissue
Metabolised by cytochrome P450 in liver to active phosphoramide mustard

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17
Q

Doxorubicin

A

Anti-cancer
Anthracycline, bind non-covalently to DNA
Prevent replication and expression
Generate free radicals due to hydroxyquinone moiety –> DNA cleavage and lipid peroxidation
Inhibitor of type 2 topoisomerase
Antibiotic - intercalates into DNA (local injection)

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18
Q

Erlotinib

A

Orally active
Small molecule ligand that inhibits EGFR tyrosine kinase
(Lung cancer)

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19
Q

Erythromycin

A

14-membered Macrolide antibiotic
Targets 23S rRNA in 50S ribosomal subunit
Bind 23S rRNA at entrance to polypeptide export tunnel
Allow 6-8 oligopeptidyl tRNA build up before terminating
Competitive with lincosamide antibiotics
Can be bacteriostatic or bactericidal
Resistance - inactivation by enzymatic hydrolysis
Second choice for penicillin allergies
Gram +ve
Short elimination half life

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20
Q

Etoposide

A

Inhibitor of human type 2 topoisomerase
Resistance can be due to modified topoisomerases
Cancer

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21
Q

Fansidar

A

A combination of sulfadoxin and pyrimethamine
Against Plasmodium falciparum malaria
Used when chloroquine resistance is suspected and oral treatment is
appropriate

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22
Q

Fluconazole

A

Antifungal synthetic triazole
Inhibits enzymes in ergosterol biosynthesis
Affects membrane permeability and activity of membrane associated enzymes
Resistance due to active azole efflux and alterations in activity and amount of enzymes
Athletes foot and vaginal cadidiasis

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23
Q

Flutamide

A

Oral anti-androgen
Prostate cancer
Competes with testosterone and powerful metabolite, dihydrotestosterone
Prevents stimulation of growth of prostate cancer cells

24
Q

Fosfomycin

A

Inhibits cell wall biosynthesis

Inhibits pyruvyl transferase (transfers PEP to UDP-NAG in production of UDP-NAM-tripeptide)

25
Q

Fusidic acid

A

Affects protein synthesis
Binds and inhibits elongation factor G, preventing movement of 30S subunit along mRNA, blocking translocation
Narrow spectrum, for staphylococcal infections

26
Q

Goseraline

A

Decapeptide analogue of GnRH that binds tightly and disrupts endogenous hormonal feedback, causing down-regulation of
testosterone and estrogen production
Biochemical castration

27
Q

Imatinib

A

Specific inhibitor of a number of tyrosine kinase enzymes (c-kit , which is over-expressed in gastro-intestinal stromal tumours GISTs)
Inhibits BCR-ACL protein kinase activity, active in CML

28
Q

Isoniazid

A

Prevention and treatment of M Tuberculosis

Inhibits biosynthesis of Mycolic acid in cell envelope

29
Q

Leucovorin

A

Adjuvant in canver chemotherapy involving methotrexate
Used in combination with 5-fluorouracil
Salvage normal tissues from folate depletion
Readily converted to reduced folic acid derivatives
Does not require action of dihydrofolate reductase, so function as vitamin unaffected by inhibition of these enzymes

30
Q

Methicillin

A

ß-lactam antibiotic
Inhibit peptidoglycan-crosslinking transpeptidase enzymes by covalent and irreversible binding as a pseudosubstrate
Resistance with mecA gene, and fem which adds pentaglycyl crossbridge to PG, making it a better MecA substrate

31
Q

Methotrexate

A

Antimetabolite and antifolate
Inhibits folic acid metabolism
Folic acid antagonist
Inhibits dihydrofolate reductase
Similar to trimethoprim (bacterial) and pyrimethamine (protazoal)
Competes with folic acid for active transport into mammalian cells
Toxicity to normal tissues, so used with Leucovorin
Resistance based on enhanced expression of DHFR or reduced uptake from mutations in folate carrier

32
Q

Miconazole

A

Antifungal synthetic imidazole
Inhibits enzymes in ergosterol biosynthesis
Also active against Leishmania, due to ergosterol membrane

33
Q

Mitomycin C

A

Aziridine containing antibiotic that alkylates and cross-links DNA
Cross-linking of 2 G bases, preventing separation of strands
Selectively inhibits DNA synthesis in bacteria and tumour cells
Activated by reduction of the quinone group

34
Q

Mitoxantrone

A

Anthracycline
Anti-cancer
Modified structure so lack quinone type free radical generation
Resistance by drug efflux by transporters

35
Q

Nevirapine

A

Anti-HIV
Non nucleoside reverse transcriptase inhibitor
Used in HAART therapy
Bind and denature catalytic site of enzyme

36
Q

Penicillin

A

Bactericidal
B-lactam antibiotic
Selective toxicity and large therapeutic index
Inhibit PG cross-linking transpeptidases by forming a slowly hydrolysing covalent acyl enzyme intermediate
Contains B-lactam and thiazolidine ring
Resistance by B-lactamases and penicillin-binding proteins

37
Q

Prednisone

A

Synthetic corticosteroid prodrug, converted by liver to prednisolone
Inhibits growth of lymphocytes in leukemias

38
Q

Pyrimethamine

A

Inhibits dihydrofolate reductase in plasmodium falciparum

Anti-protazoa

39
Q

Rifampin

A

Bactericidal, inhibit RNA synthesis
Binds B-subunit of DNA dependent RNA polymerase (tight but non-covalent)
Directly blocks elongating RNA chain - prevents initiation of RNA synthesis
Synthesis in progress at time of exposure is unaffected
Intrinsic resistance by fungi, because drug does not readily enter envelope, so concentration is low
Used to treat mycobacterium infections

40
Q

Saquinavir

A

Inhibit HIV protease, essential for viral replication and release of virus particles
Used in HAART therapy

41
Q

Streptomycin

A

Aminoglycoside, affects protein synthesis, acts on 30S subunit
Binds the 30S subunit near the A
site for aminoacyl-tRNA binding
Cause disruption in decoding and translational accuracy, decrease in the fidelity of translation
Nephrotoxicity and ototoxicity
Gram negative rods

42
Q

Sulfadoxin

A

Sulfa drug, competitively inhibits dihydropteroate synthase in plasmodium

43
Q

Sulfamethoxazole

A

Antimetabolite antibiotic
A sulfa drug; p-aminobenzoate analogue
Competitively inhibits dihydropteroate synthase in the biosynthesis of tetrahydrofolate
(methyl carrier required for synthesis of dTMP).

44
Q

Suramin

A

Used for human trypanosomiasis
Does not contain toxic metal, so high therapeutic index
inhibits glycerol-3-phosphate oxidase and NAD+-dependent glycerol-3-phosphate dehydrogenase
Interferes with the reoxidation of NADH, and inhibits ATP synthesis

45
Q

Tamoxifen

A

Orally-active oestrogen receptor antagonist used in the treatment of breast cancer
Signal transduction inhibitor
Attenuates transcription of estrogen responsive genes involved in breast cancer
Exerts estrogen agonist effects in other tissues such as bone and uterus

46
Q

Taxol

A

Causes assembly of microtubules from tubulin dimers
Causes stabilization of ordinary cytoplasmic microtubules and the formation of abnormal bundles of microtubules
Taxane, mitotic inhibitor

47
Q

Tetracycline

A

Bacteriostatic antibiotic
Polyketide antibiotic; binds to 16 rRNA in 30S subunit of ribosome and inhibits the movement of aminoacyl-tRNA into the A site
Effective against a wide range of bacteria, and are first-line drugs against mycoplasma and cholera
Drug toxicity associated with binding of calcium in bones and teeth.
Resistance - specific tetracycline efflux transporters

48
Q

Topotecan

A

Inhibit human type 1 topoisomerase

Ovarian and lung cancer

49
Q

Trastuzumab

A

A humanised monoclonal antibody against the human epidermal growth factor receptor 2 (HER2) in breast cancer
IV once a week
Can cause cardiac dysfunction

50
Q

Trimethoprim

A

Antimetabolite antibiotic

Inhibits dihydrofolate reductase in folic acid biosynthesis (tetrahydrofolate)

51
Q

Valinomycin

A

Antibiotic acting on cytoplasmic membrane
Ionophoretic capacity
Electroneutral, but carries single +ve charge of K+
A cyclic peptide antibiotic that binds K+, and facilitates K+ diffusion across the membrane

52
Q

Vancomycin

A

Glycopeptide antibiotic
Binds pentapeptidyl tails in PG repeating unit terminating in D-Ala-D-Ala
Prevents transpeptidation
Effective against Clostridium Difficile and used IV for Gram +ve cocci

53
Q

Vinblastine

A

Vinca alkaloid
Antimitotic drug
Anti-cancer

54
Q

Zanamivir

A

Inhibits neuraminidase, a glycoprotein enzyme, of Influenza A and maybe B
Enhance viral aggregation and inhibit release from the host cells

55
Q

Zidovudine AZT

A

Nucleoside reverse transcriptase inhibitor
Thymidine analogue
Used in HAART treatment

MODA List 1 (8 decks)

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