Exam 5 - Antimalarial Flashcards Preview

Therapeutics V Spring 2019 (P3 Spring) > Exam 5 - Antimalarial > Flashcards

Flashcards in Exam 5 - Antimalarial Deck (66):
1

Malaria:
what are the different parasites?

plasmodium falciparum***
plasmodium vivax*** - causes relapses
plasmodium ovale -- causes relapses
plasmodium malariae
plasmodium knowlesi
*** = most common

2

what vaccine is available for malaria?

noneee

3

Life Cycle of Plasmodium Falciparum:
1. infected ______ inject _______

mosquito
sporozoites

4

Life Cycle of Plasmodium Falciparum:
2. Sporozites migrate to the _____ where they become _______

liver;
merozoites

5

Life Cycle of Plasmodium Falciparum:
3. Merozoites are released and invade ______

red blood cells

6

Life Cycle of Plasmodium Falciparum:
4. Once the merozoite is in the red blood cel it becomes a _______

trophozoite

7

Life Cycle of Plasmodium Falciparum:
Some merozoites can become ________ (not just trophozoite)

gametocytes

8

Ways to prevent malaria?

Prevention: insect repellents/insecticides/bed nets
or Chemoprophylaxis

9

what are some common malaria chemoprophylaxis

-atovaquone-proguanil
-chloroquine
-mefloquine
-primaquine

10

how are antimalarial drugs classified?

based on what stage the drug kills the malaria bugs

11

what are the 3 different stages a drug could attack the malaria?

tissue schizonticides
blood schizonticides
gametocytocides

12

tissue schizonticides: kill the ______ parasites

liver stage

13

blood schizonticides kills ______ forms

erythrocytic

14

gametocytocides: kill the _______ and block ______

sexual stages;
block transmission

15

what are the 6 different antimalarial drug classes

artemisinin
4-aminoquinolines
8-aminoquinolines
atovaquone
antifolates
antibiotics

16

Artemisinin:
High or low toxicity?
Works fast or low?

LOW toxicity
and works fast (but also lasts not a long time..)

17

MOA of Artemisinin:
must be activated via _______
once activated it may form ________
and targets parasite proteins and lipids

via heme-iron
form free radicals

18

Artemisinin mechanism of resistance:
Mutations in _____ gene and causes _________

kelch 13; delays in progression through the life cycle

19

how does kelch13 work against artemisinin?

it enhances the stress response/helps malaria resist the drug

20

Artemisinin:
is active against what form of malaria?

blood schizonticide

21

Artemisinin:
bolus or infusion is best and why?

bolus bc PEAK/MIC is how it works

22

Artemisinin gets converted to ________ which is the active part

dihydroartemisinin

23

what drugs are 4-aminoquinolines

quinine
chloroquine
mefloquine

24

the -N group on the 4-aminoquinolines is a (weak or strong) (acid or base)

and what is that substiuients role

weak base
assists in drug accumulation via pH trapping

25

Malaria and its mechanism:
it ingests _______ from host cells

hemoglobin

26

Malaria and its mechanism:
it degrades hemoglobin to amino acids and _______ (which is toxic) in the food vacuole

free heme

27

Malaria and its mechanism:
Parasites ___________ heme into hemozoin to make it nontoxic

polymerize

28

how do 4-aminoquinlones works

accumulate in the food vacuole and inhibit heme polymerization

29

resistance seen against 4-aminoquinolones

-lack of accumulation of the aminoquinolone in food vacuole
-mutation in PfCRT1

30

Quinine or Chloroquine:
shorter half life and toxicity is worse aka it cannot be chemoprophylaxis

quinine

31

MOA atovaquone?

selective inhibitor of malaria mitochondrial cytochrome bc1 complex

32

MOA proguanil?

when convereted to cycloguanil -- selective inhibitor for DHFR-TS (dihydrofolate reductase thmidylate synthetase)

and regular proguanil is synergistic with atovaquone

33

MOA of artemesinin?

free radical

34

MOA of chloroquine?

accum. in food vacuole/heme toxin build up

35

MOA quinine?

accum. in food vacuole/heme toxin build up

36

MOA of primaquine?

free radical

37

MOA doxycycline?

targets apicloplast (plant like organelle that carries out many biochemical processes

38

how is primaquine activated

CYP 2D6

39

Contraindications of primaquine?

-granulocytopenia
-concurrent use of other hemolytic drugs/drugs that suppress myeloid cell development

40

Primaquine: high risk of _______ if G6PD deficiency

hemolysis

41

key functional group in artemisinin?

endoperoxide

42

ADEs of Quinine?

-cinchonism: tinnitis, HA, nausea, dizziness, flushing, visual disturbances
-stimulate uterine contractions
-hemolysis (G6PD)
-severe hypotension if too rapid of infusion

43

ADEs of Primaquine?

hemolysis high risk
avoid in breastfeeding women

CIs:-granulocytopenia
-concurrent use of other hemolytic drugs/drugs that suppress myeloid cell development

44

what drug is DOC for liver stages of P.vivax and P.ovale

primaquine

45

Sxs of giardiasis

diarrheal disease

46

Sxs amebiasis

diarrhea/flatulence/abdominal cramps

47

drugs to treat toxoplasma

1st line: pyrimethamine + sulfadiazene
alternative: atovaquone or pentamidine

48

drugs to treat amebiasis

paromomycin
idoquinol

49

drugs to treat trichomonas

metronidazole

50

Spectrum of Metronidazole?

Giardiasis
trichamoniasis

(anaerobes)

51

Spectrum of Nitazoxanide?

inhibits growh of sporozoites andoocysts of cryptosporidiu parvum and trophozoites of giardia lamblia

52

Spectrum of Paromomycin?

an aminoglycoside for INTESTINAL FORM of amebiasis and cryptosporidium

53

MOA of nitazoxanide?

interferes with PFOR (pyruvate ferredoxin oxidoreductase)
inhibits anaerobic metabolism

54

MOA of metronidazole?

free radicals/anaerobes have electron transport proteins with low redox potential

55

what bug causes river blindness

onchocerciasis

56

what bug causes elephantiasis

filariasis

57

what do benzimidazoles cover
(ex: mebendazole, thiabendazole, albendazole)

helminths

58

MOA of Benzimidazoles?

bind to tubulin/inhibit formation of microtubules

59

Praziquantel: spectrum covers 2 of the following - what are they?

cestodes
nematodes
treamtodes

cestodes and treamtodes

60

MOA of ivermectin

paralyzes microfilarie/binds to glutamate activated chloride channels on nerve muscle cells

61

Ivermectin is primarily used for ______

onchocercisasis

62

MOA of pyrantel pamoate

worms are paralyzed/expelled

depolarizing neuromuscular blocking agent/Ach/cholinesterae effects

63

MOA of nifurtimox and benznidazole?

activated by NADH dependent mitochondrial nitroreductase

generates nitro radical anions

64

treatment of Giardia?

metronidazole
nitazoxanide

65

what is the nickname for T.Cruzi and T. brucei

Sleeping sickness:
Cruz: American one
Brucei: African

66

Nifurtimox/Benznidazole:
covers what bugs

T.Cruzi/Brucei aka trypanosomiasis aka sleeping sickness