Exam 6 - Antimalarial

Question 1

Malaria:

what are the different parasites?

Answer 1

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

Question 2

what vaccine is available for malaria?

Answer 2

noneee

Question 3

Life Cycle of Plasmodium Falciparum:

1. infected ______ inject _______

Answer 3

mosquito

sporozoites

Question 4

Life Cycle of Plasmodium Falciparum:

2. Sporozites migrate to the _____ where they become _______

Answer 4

liver;

merozoites

Question 5

Life Cycle of Plasmodium Falciparum:

3. Merozoites are released and invade ______

Answer 5

red blood cells

Question 6

Life Cycle of Plasmodium Falciparum:

4. Once the merozoite is in the red blood cel it becomes a _______

Answer 6

trophozoite

Question 7

Life Cycle of Plasmodium Falciparum:

Some merozoites can become ________ (not just trophozoite)

Answer 7

gametocytes

Question 8

Ways to prevent malaria?

Answer 8

Prevention: insect repellents/insecticides/bed nets

or Chemoprophylaxis

Question 9

what are some common malaria chemoprophylaxis

Answer 9

• atovaquone-proguanil
• chloroquine
• mefloquine
• primaquine

Question 10

how are antimalarial drugs classified?

Answer 10

based on what stage the drug kills the malaria bugs

Question 11

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

Answer 11

tissue schizonticides
blood schizonticides
gametocytocides

Question 12

tissue schizonticides: kill the ______ parasites

Answer 12

liver stage

Question 13

blood schizonticides kills ______ forms

Answer 13

erythrocytic

Question 14

gametocytocides: kill the _______ and block ______

Answer 14

sexual stages;

block transmission

Question 15

what are the 6 different antimalarial drug classes

Answer 15

artemisinin
4-aminoquinolines
8-aminoquinolines
atovaquone
antifolates
antibiotics

Question 16

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

Answer 16

LOW toxicity

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

Question 17

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

Answer 17

via heme-iron

form free radicals

Question 18

Artemisinin mechanism of resistance:

Mutations in _____ gene and causes _________

Answer 18

kelch 13; delays in progression through the life cycle

Question 19

how does kelch13 work against artemisinin?

Answer 19

it enhances the stress response/helps malaria resist the drug

Question 20

Artemisinin:

is active against what form of malaria?

Answer 20

blood schizonticide

Question 21

Artemisinin:

bolus or infusion is best and why?

Answer 21

bolus bc PEAK/MIC is how it works

Question 22

Artemisinin gets converted to ________ which is the active part

Answer 22

dihydroartemisinin

Question 23

what drugs are 4-aminoquinolines

Answer 23

quinine
chloroquine
mefloquine

Question 24

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

and what is that substiuients role

Answer 24

weak base

assists in drug accumulation via pH trapping

Question 25

Malaria and its mechanism: | it ingests _______ from host cells

Answer 25

hemoglobin

Question 26

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

Answer 26

free heme

Question 27

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

Answer 27

polymerize

Question 28

how do 4-aminoquinlones works

Answer 28

accumulate in the food vacuole and inhibit heme polymerization

Question 29

resistance seen against 4-aminoquinolones

Answer 29

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

Question 30

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

Answer 30

quinine

Question 31

MOA atovaquone?

Answer 31

selective inhibitor of malaria mitochondrial cytochrome bc1 complex

Question 32

MOA proguanil?

Answer 32

when convereted to cycloguanil -- selective inhibitor for DHFR-TS (dihydrofolate reductase thmidylate synthetase) and regular proguanil is synergistic with atovaquone

Question 33

MOA of artemesinin?

Answer 33

free radical

Question 34

MOA of chloroquine?

Answer 34

accum. in food vacuole/heme toxin build up

Question 35

MOA quinine?

Answer 35

accum. in food vacuole/heme toxin build up

Question 36

MOA of primaquine?

Answer 36

Produce H2O2 to kill plasmodium parasites

Question 37

MOA doxycycline?

Answer 37

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

Question 38

how is primaquine activated

Answer 38

CYP 2D6

Question 39

Contraindications of primaquine?

Answer 39

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

Question 40

Primaquine: high risk of _______ if G6PD deficiency

Answer 40

hemolysis

Question 41

key functional group in artemisinin?

Answer 41

endoperoxide

Question 42

ADEs of Quinine?

Answer 42

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

Question 43

ADEs of Primaquine?

Answer 43

hemolysis high risk avoid in breastfeeding women CIs:-granulocytopenia -concurrent use of other hemolytic drugs/drugs that suppress myeloid cell development

Question 44

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

Answer 44

primaquine

Question 45

Sxs of giardiasis

Answer 45

diarrheal disease

Question 46

Sxs amebiasis

Answer 46

diarrhea/flatulence/abdominal cramps

Question 47

drugs to treat toxoplasma

Answer 47

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

Question 48

drugs to treat amebiasis

Answer 48

paromomycin | idoquinol

Question 49

drugs to treat trichomonas

Answer 49

metronidazole

Question 50

Spectrum of Metronidazole?

Answer 50

Giardiasis trichamoniasis (anaerobes)

Question 51

Spectrum of Nitazoxanide?

Answer 51

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

Question 52

Spectrum of Paromomycin?

Answer 52

an aminoglycoside for INTESTINAL FORM of amebiasis and cryptosporidium

Question 53

MOA of nitazoxanide?

Answer 53

interferes with PFOR (pyruvate ferredoxin oxidoreductase) | inhibits anaerobic metabolism

Question 54

MOA of metronidazole?

Answer 54

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

Question 55

what bug causes river blindness

Answer 55

onchocerciasis

Question 56

what bug causes elephantiasis

Answer 56

filariasis

Question 57

what do benzimidazoles cover | ex: mebendazole, thiabendazole, albendazole

Answer 57

helminths

Question 58

MOA of Benzimidazoles?

Answer 58

bind to tubulin/inhibit formation of microtubules

Question 59

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

Answer 59

cestodes and treamtodes

Question 60

MOA of ivermectin

Answer 60

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

Question 61

Ivermectin is primarily used for ______

Answer 61

onchocercisasis

Question 62

MOA of pyrantel pamoate

Answer 62

worms are paralyzed/expelled depolarizing neuromuscular blocking agent/Ach/cholinesterae effects

Question 63

MOA of nifurtimox and benznidazole?

Answer 63

activated by NADH dependent mitochondrial nitroreductase generates nitro radical anions

Question 64

treatment of Giardia?

Answer 64

metronidazole | nitazoxanide

Question 65

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

Answer 65

Sleeping sickness: Cruz: American one Brucei: African

Question 66

Nifurtimox/Benznidazole: | covers what bugs

Answer 66

T.Cruzi/Brucei aka trypanosomiasis aka sleeping sickness