Anti-Malaria drugs Flashcards
Which two species can remain dormant in the liver?
vivax and ovale
which is the most lethal form of plasmodia?
falciparum
can you get falciparum in the brain?
yes
is p. ovale rare or common?
rare
What drugs are considered blood schizonticides?
chloroquine/hydroxychloroquine
quinine sulfate and quinidine gluconate
doxycycline
clindamycin
artemisinin
if chloroquine resistance, what is the recommended therapeutic regimen?
artemisinine based combination therapy (ACT) with either:
- Artesunate + atovoquone/proguanil
OR
artemether-lumefantrine
- quinine + doxy/tetra or clinda
- artesunate + mefloquine
- artesunate + sulfadoxine-pyrimethamine
what is the mechanism of action for chloroquine?
concentrated w/in plasmodia in RBCs.
Interferes with lysosomal degradation of Hb
describe the absorption of chloroquine
well absorbed in GI but inhibited by Mg and Ca
where does chloroquine accumulate?
in melanin rich tissue: skin and retina
This drug has the following adverse effects:
retinal and corneal toxicity.
some ototoxicity
hemolysis (G6PD deficiency)
QT prolongation
chloroquine
what are contraindications for chloroquine?
psoriasis and porphyria
When should you consider artemisinin combination treatment?
for uncomplicated chloroquine resistant falciparum and vivax species
when treating chloroquine resistant malaria, which ACT therapies are recommended
artesunate + atovoquone-proguanil
OR
artemether + lumefantrine
when should you use artesunate + mefloquine?
drug of last resort
when should you use artesunate + sulfadoxine-pyrimethamine?
empirical therapy or IPT in pregnancy
which drugs are folate metabolism inhibitors?
Proguanil and pyrimethamine-sulfadoxine
On what forms of malaria do folate metabolism inhibitors work?
erythrocytic forms
Sulfadoxine is a sulfa drug, which means you should be concerned for…
hypersensitivity and toxicity
describe the absorption of atovaquone-proguanil…
taken orally with fatty foods
proguanil is a prodrug that is converted to what and has what activity…
cycloguanil, DHF reductase inhibitor
describe the mechanism of action of atovaquone…
interferes w/ ETC and ATP/pyrimidine synthesis by blocking DHF metabolism
What side effects of atovaquone-proguanil require discontinueation?
rash, fever, vomiting, diarrhea
with what drug should lumefantrine be administered?
artemether
what are the adverse effects of lumefantrine?
headache, prolonged QT
when should you consider using Quinidine?
complicated, chloroquine resistant plasmodia
What drugs do you combine with quinidine and why?
doxy, tetra, clinda to reduce length of tx and adverse effects
describe the serious side effects of quinine/quinidine
cinchonism
antiarrhythmia
QT elongation (esp. w/ mefloquine)
GI sx
Hemolysis in G6PD
which antibiotic is given for prophylaxis to MDR malaria?
doxy
which abx is preferred to treat malaria?
tetracyclines
where is mefloquine absorbed and what is its bioavailability?
GI with bioavailability > 85%
Why can mefloquine be administered in a single dose?
very slow bile/fecal elimination
describe the toxic effects of mefloquine
myocardial depression
seizures
aggravate latent psychosis
vivid dreams
for whom should you not administer mefloquine?
Pregnant
hx of mental illness or epilepsy
combination w/ quinine
pyrimethamine + sulfadoxine is used when?
empirical and preventative therapy in pregnant women
what is pyrimethamine + sulfadxine combined with?
artesunates to prevent resistance
Why is pyrimethamine + sulfadoxine off the market in the US?
serious adverse effects and fatalities due to SJS/TEN
what are the two tissue schizonticides?
primaquine, tafenoquine
is primaquine active in erythrocytic forms?
no, only exoerythrocytic
after cure, what else is primaquine used for?
terminal prophylaxis
primaquine is contraindicated for which patients?
SLE, RA-graunulocytopenia
what is a serious adverse effect of primaquine for which population?
hemolytic anemia for those with G6PD deficiency.
can you give primaquine to those with G6PD deficiency?
yes-low dose once weekly for 8 weeks
why shouldn’t primaquine be administered to pregnant/breastfeeding women or infants < 6mo?
fetal hemolytic anemia
for what stages and tissue forms is tafenoquine active?
all stages and tissue forms
Describe the half life of tafenoquine and what can result due to this…
long half life, single dose treatment
at what ages is tafenoquine approved for clinical cure and radical cure?
clinical: 18 yo
radical: 16 yo
For people with G6PDD or unknown G6PDD status, what drug can you consider for radical cure?
Tafenoquine
besides radical cure of vivax and ovale, what else is tafenoquine approved for?
terminal prophylaxis
