Anti-Malaria drugs

Question 1

Which two species can remain dormant in the liver?

Answer 1

vivax and ovale

Question 2

which is the most lethal form of plasmodia?

Answer 2

falciparum

Question 3

can you get falciparum in the brain?

Answer 3

yes

Question 4

is p. ovale rare or common?

Answer 4

rare

Question 5

What drugs are considered blood schizonticides?

Answer 5

chloroquine/hydroxychloroquine

quinine sulfate and quinidine gluconate

doxycycline

clindamycin

artemisinin

Question 6

if chloroquine resistance, what is the recommended therapeutic regimen?

Answer 6

artemisinine based combination therapy (ACT) with either:

1. Artesunate + atovoquone/proguanil

OR

artemether-lumefantrine

2. quinine + doxy/tetra or clinda
3. artesunate + mefloquine
4. artesunate + sulfadoxine-pyrimethamine

Question 7

what is the mechanism of action for chloroquine?

Answer 7

concentrated w/in plasmodia in RBCs.

Interferes with lysosomal degradation of Hb

Question 8

describe the absorption of chloroquine

Answer 8

well absorbed in GI but inhibited by Mg and Ca

Question 9

where does chloroquine accumulate?

Answer 9

in melanin rich tissue: skin and retina

Question 10

This drug has the following adverse effects:

retinal and corneal toxicity.

some ototoxicity

hemolysis (G6PD deficiency)

QT prolongation

Answer 10

chloroquine

Question 11

what are contraindications for chloroquine?

Answer 11

psoriasis and porphyria

Question 12

When should you consider artemisinin combination treatment?

Answer 12

for uncomplicated chloroquine resistant falciparum and vivax species

Question 13

when treating chloroquine resistant malaria, which ACT therapies are recommended

Answer 13

artesunate + atovoquone-proguanil

OR

artemether + lumefantrine

Question 14

when should you use artesunate + mefloquine?

Answer 14

drug of last resort

Question 15

when should you use artesunate + sulfadoxine-pyrimethamine?

Answer 15

empirical therapy or IPT in pregnancy

Question 16

which drugs are folate metabolism inhibitors?

Answer 16

Proguanil and pyrimethamine-sulfadoxine

Question 17

On what forms of malaria do folate metabolism inhibitors work?

Answer 17

erythrocytic forms

Question 18

Sulfadoxine is a sulfa drug, which means you should be concerned for…

Answer 18

hypersensitivity and toxicity

Question 19

describe the absorption of atovaquone-proguanil…

Answer 19

taken orally with fatty foods

Question 20

proguanil is a prodrug that is converted to what and has what activity…

Answer 20

cycloguanil, DHF reductase inhibitor

Question 21

describe the mechanism of action of atovaquone…

Answer 21

interferes w/ ETC and ATP/pyrimidine synthesis by blocking DHF metabolism

Question 22

What side effects of atovaquone-proguanil require discontinueation?

Answer 22

rash, fever, vomiting, diarrhea

Question 23

with what drug should lumefantrine be administered?

Answer 23

artemether

Question 24

what are the adverse effects of lumefantrine?

Answer 24

headache, prolonged QT

Question 25

when should you consider using Quinidine?

Answer 25

complicated, chloroquine resistant plasmodia

Question 26

What drugs do you combine with quinidine and why?

Answer 26

doxy, tetra, clinda to reduce length of tx and adverse effects

Question 27

describe the serious side effects of quinine/quinidine

Answer 27

cinchonism

antiarrhythmia

QT elongation (esp. w/ mefloquine)

GI sx

Hemolysis in G6PD

Question 28

which antibiotic is given for prophylaxis to MDR malaria?

Answer 28

doxy

Question 29

which abx is preferred to treat malaria?

Answer 29

tetracyclines

Question 30

where is mefloquine absorbed and what is its bioavailability?

Answer 30

GI with bioavailability > 85%

Question 31

Why can mefloquine be administered in a single dose?

Answer 31

very slow bile/fecal elimination

Question 32

describe the toxic effects of mefloquine

Answer 32

myocardial depression

seizures

aggravate latent psychosis

vivid dreams

Question 33

for whom should you not administer mefloquine?

Answer 33

Pregnant

hx of mental illness or epilepsy

combination w/ quinine

Question 34

pyrimethamine + sulfadoxine is used when?

Answer 34

empirical and preventative therapy in pregnant women

Question 35

what is pyrimethamine + sulfadxine combined with?

Answer 35

artesunates to prevent resistance

Question 36

Why is pyrimethamine + sulfadoxine off the market in the US?

Answer 36

serious adverse effects and fatalities due to SJS/TEN

Question 37

what are the two tissue schizonticides?

Answer 37

primaquine, tafenoquine

Question 38

is primaquine active in erythrocytic forms?

Answer 38

no, only exoerythrocytic

Question 39

after cure, what else is primaquine used for?

Answer 39

terminal prophylaxis

Question 40

primaquine is contraindicated for which patients?

Answer 40

SLE, RA-graunulocytopenia

Question 41

what is a serious adverse effect of primaquine for which population?

Answer 41

hemolytic anemia for those with G6PD deficiency.

Question 42

can you give primaquine to those with G6PD deficiency?

Answer 42

yes-low dose once weekly for 8 weeks

Question 43

why shouldn’t primaquine be administered to pregnant/breastfeeding women or infants < 6mo?

Answer 43

fetal hemolytic anemia

Question 44

for what stages and tissue forms is tafenoquine active?

Answer 44

all stages and tissue forms

Question 45

Describe the half life of tafenoquine and what can result due to this…

Answer 45

long half life, single dose treatment

Question 46

at what ages is tafenoquine approved for clinical cure and radical cure?

Answer 46

clinical: 18 yo
radical: 16 yo

Question 47

For people with G6PDD or unknown G6PDD status, what drug can you consider for radical cure?

Answer 47

Tafenoquine

Question 48

besides radical cure of vivax and ovale, what else is tafenoquine approved for?

Answer 48

terminal prophylaxis