PHARM_ANTIPARASITICS

Question 1

MOA chloroquine?

Answer 1

intracellular heme accumulation; toxic

Question 2

moa quinine

Answer 2

DNA complexer; prevents strand separation

Question 3

MOA primaquine

Answer 3

free radical generators in plasmodium

Question 4

MOA pyrimethamine, proguanil

Answer 4

pyrimethamine, proguanil = DHFR inhibitors

sulfadoxine = dihydropteroate synthase inhibitor

combo of pyrimethamine w/ sulfadoxine sequentially blocks folic acid synth.

Question 5

MOA atovaquone-proguanil

Answer 5

inhibits mitochondrial ETC

Question 6

MOA artesunate, artemether

Answer 6

free radical generators in plasmodium

Question 7

MOA atovaquone

Answer 7

inhibits ETC

Question 8

what is the target for chloroquine?

Answer 8

blood schizonticide

Question 9

what is the target for mefloquine?

Answer 9

blood schizonticide

Question 10

what is the target for quinine?

Answer 10

blood schizonticide

Question 11

what is the only antimalarial drug that has activity against liver schizonts (vivax & ovale)?

Answer 11

primaquine

Question 12

what is the target of atovaquone-proguanil therapy?

Answer 12

blood schizonticide (falciparum)

Question 13

what is the target of artesunate, artemether?

Answer 13

blood schizonticide (falciparum) including multidrug resistant strains

Question 14

what is the target of proguanil?

Answer 14

slow acting blood schizonticide + prevents sporogeny in mosquito

Question 15

what is the target of pyrimethamine?

Answer 15

blood schizonticide

Question 16

what is the mechanism of resistance to chloroquine?

Answer 16

decreased intracellular &/or decreased intravacuolar drug accumulation

Question 17

describe the pharmacokinetic properties of chloroquine?

Answer 17

orally active high Vd-long persistance some hepatic metab., renal elimination

Question 18

describe the PK properties and metabolism of artesunate and artemether

Answer 18

oral; poorly water soluble, but levels achieved exceed cytotoxic requirement short half-lives wide TI

Question 19

explain the mechanism of hemolytic anemia induced by primaquine in african american males with G6PD deficiency

Answer 19

G6PD protects rbc from ROS, antimalarial causes buildup of ROS that is toxic

Question 20

describe the toxic adverse effect of chloroquine

Answer 20

Irreversible retinopathy, maculopathy, and macular degeneration

• most often after long-term or high-dose therapy
• regular opthalm. exam should be done for all pts getting long-term therapy & drug discontinued at 1st sign of any adverse rxn Abnormal ECG; prlonged QT interval

Question 21

which drug causes cinchonism?

Answer 21

quinine

Question 22

what are the most common symptoms occurring from long-term exposure to quinine?

Answer 22

Cinchonism: repeated headaches Nausea blurred vision tinnitus hearing impairment-deafness

Question 23

what are the drugs of choice for treating uncomplicated malaria/P. falciparum in a region of chloroquine resistance or unknown resistance?

Answer 23

atovaquone-proguanil artemether-lumefantrine quinine + doxy or tetracycline or clindamycin Melfoquine *if species not identified is subseq. diagnosed as P. Vivax or P. ovale then retreat with primaquine

Question 24

what are drugs of choice for all regions in treating p. malariae?

Answer 24

chloroquine or hydroxychloroquine

Question 25

what are the drugs of choice in all regions for treating P. vivax or ovale?

Answer 25

chloroquine or HC + primaquine

Question 26

what are the drugs of choice in treating P. ovale in regions with chloroquine resistance?

Answer 26

quinine + doxy or tetracycline atovaquone-proguanil + primaquine

Question 27

what are the drugs of choice for treating pregnant women with malaria?

Answer 27

chloroquine or hydroxychloroquine quinine + clindamycine OR mefloquine

Question 28

what are the drugs of choice for treating P. falciparum in all regions?

Answer 28

quinidine + one of the following: doxy, tetracycline, clindamycin contact CDC for artesunate followed by atovaquone-proguaanil, doxy, or mefloquine (clindamycin in pregn.)

Question 29

which antimalarial drug requires a loading dose to achieve effective plasma concentration?

Answer 29

chloroquine (has a large volume of distribution)

Question 30

which antimalarial drug most likely produces hemolytic anemia in a pt with G6PD deficiency?

Answer 30

primiquine but also: quinine

Question 31

which antimalarial drug is combined with proguanil (folate antagonist) to form an effective treatment for chemoprophylaxis of falciparum malaria?

Answer 31

atovaquone

Question 32

If you have a pt taking a drug for malaria with headache, vertigo, blurred vision, and tinnitus, what drug were they taking?

Answer 32

quinine (this is cinchonism)

Question 33

name the 4 sets of drugs that are used to treat uncomplicated chloroquine-resistant P. falciparum?

Answer 33

Atovaquone-proguanil Artemether-lumefantrine Quinine-doxycycline Mefloquine