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Flashcards in Malaria Drugs Deck (28):
1

Quinine (Qualaquin)

Class: Quinolone derivitive
Mech: Accumulate in parasite’s food vacuole, disrupt heme polymerization to hemozoin, yielding oxidative damage to membranes and digestive proteases
Thera: Prophylaxis, treatment of acute malarial attacks
Important SE's: Cinchonism, hypotension, hypoglycemia, abortion, arrhythmias
Misc: Also called quinidine (used in anti-arrhythmias)

2

Chloroquine (Aralen)

Class: Quinolone derivitive
Mech: Accumulate in parasite’s food vacuole, disrupt heme polymerization to hemozoin, yielding oxidative damage to membranes and digestive proteases
Thera: Prophylaxis, treatment of acute malarial attacks
Important SE's: Itching (Africans), retinitis (rare)

3

Hydroxychloroquine (Plaquenil)

Class: Quinolone derivitive
Mech: Accumulate in parasite’s food vacuole, disrupt heme polymerization to hemozoin, yielding oxidative damage to membranes and digestive proteases
Thera: Prophylaxis, treatment of acute malarial attacks

4

Mefloquine (Lariam)

Class: Quinolone derivitive
Mech: Accumulate in parasite’s food vacuole, disrupt heme polymerization to hemozoin, yielding oxidative damage to membranes and digestive proteases
Thera: Prophylaxis, treatment of acute malarial attacks

5

Primaquine (Primaryl)

Class: Quinolone derivitive
Mech: Forms quinolone-quinone intermediates that oxidize schizont membranes
Thera: Prophylaxis, treatment of acute malarial attacks, also prevent relapses
Important SE's: Hemolysis (G6PD deficiency), methemoglobinemia
Other SE's: Fever, nausea, vomiting
Misc: Only drug that inhibits exoerythrocytic schyzogony

6

Amantadine (Symmetrel)

Mech: Positive charge helps chloroquine overcome chloroquine-resistant malaria vacuoles; point mutations against amantadine return bacteria to chloroquine-sensitivity

7

Artesunate

Class: Artemisinin compound
Mech: Specifically and selectively inhibit SERCA of P. falciparum
Important SE's: Neurotoxicity, prolongation of QT interval
Misc: can use IV form for severe cases of malaria

8

Artemether

Class: Artemisinin compound
Mech: Specifically and selectively inhibit SERCA of P. falciparum

9

Lumefantrine

Class: Aminoalcohol
Thera: Used in combination w/artemether (called Coartem); want to avoid resistance!!
Misc: Also called benflumentol

10

Atovaquone (Mepron)

Class: Napthalene
Mech: Depolarizes parasitic mitochondria and inhibits their electron transport
Thera: Used in combination w/proguanil
Misc: use for prophylaxis and treatment of malaria due to P. falciparum, including chloroquine-resistant strains

11

Chloroguanide (Malarone)

Class: Antifolates
Mech: Dihydrofolate reductase inhibitors (human and parasite pathway)
Important SE's: Rare
Misc: Also called proguanil

12

Tetracycline (Tetracyn)

Class: Antibiotic
Thera: Severe malaria & chloroquine-resistant uncomplicated malaria

13

Clindamycin (Cleocin)

Class: Antibiotic
Thera: Severe malaria & chloroquine-resistant uncomplicated malaria

14

Doxycycline (Adoxa)

Class: Antibiotic
Thera: Severe malaria & chloroquine-resistant uncomplicated malaria
Important SE's: Photosensitivity

15

Characteristics of the five human forms of malaria?

1. P vivax: wide distribution, often involved in relapses
2. P falciparum: most lethal and common, much resistance to major drugs
3. P malariae: less common, could cause asymptomatic infections that can last for decades
4. P ovale: less common, involved in relapses
5. P knowlesi: thought to be just monkeys, but now some cases in humans

16

Clinical signs of malaria

1. Periodic episodes of chills and fevers
2. Usually enlarged liver and spleen
3. Identified parasites in blood smears

17

Frequency of febrile paroxysms:

Vivax: 2 days;
Malariae: 3 days;
Falciparum: irregular

18

Quinoline derivatives include

quinine/quinidine, chloroquine, mefloquine, primaquine

19

What is the only parenteral antimalarial available in the US?

Quinine/quinidine (latter with gluconate)

20

Chloroquine's uses and where is there sensitivity and resistance?

Prophylaxis and acute attacks;
sens: Central America, Saudi Arabia and Egypt;
resistance: a lot of Africa, Asia, South America

21

List how chloroquine works on cells with parasites (mechanism):

1. Chloroquine can't leave digestive vacuoles if there is a point mutation preventing chloroquine release
2. Chloroquine can be released if there is a mutation in that positive charge
3. Give amantadine (an antiviral) that can prevent CQ from exiting again, allowing for toxic complexes of chloroquine and heme to accumulate
4. If there's a mutation such that the channel is resistant to the amantadine, it becomes CQ sensitive again!!

22

SE's of mefloquine

Affects nervous system and causes psychotic effects

23

What does a drug take advantage of to get into a digestive vacuole?

Uses a pH gradient (going from 7.4 to 4.8 from the plasma, RBC cytoplasm, parasite cytoplasm, to food vacuole

24

Chemoprophylaxis: what do you use in four different areas

CQ-sens zone: chloroquine;
CQ-resistant zone: mefloquine, doxycycline, atovaquone/proguanil;
mefloquine-resistant zone: doxycycline, atovaquone/proguanil;
terminal prophylaxis: primaquine

25

For treatment of severe malaria, what protocol can you follow?

1. IV quinidine gluconate plus tetracycline, doxycycline, or clindamycin (ICU, cardiac function, parasitemia, glucose, Hb, electrolytes)
2. IV artesunate followed by atovaquone-proguanil, doxycycline (dlindamycin in pregnant women), or mefloquine
3. Exchange blood transfusion (if altered mental status, pulmonary edema, renal complications)

26

How to treat chloroquine sens strains?

1. P falciparum, malariae, or knowlesi by chloroquine phosphate with alternative hydroxychloroquine
2. P vivax, ovale: chloroquine phosphate and primaquine phosphate (with alternative hydroxychloroquine and primaquine phosphate)

27

How to treat CQ-resistant strains?

1. P falciparum: atovaquone-proguanil (alternatives artemether-lumefantrine, quinine sulfate plus either doxy, tetra, or clindo for children younger than 8 or preg, and mefloquine)
2. P. vivax: quinine sulfate and doxy or tetra, and primaquine phosphate, with alternatives atovaquone-proguanil + primaquine phosphate, or mefloquine and primaquine phosphate

28

To eradicate persistent exoerythrocytic parasites after clinical cure of acute attack by _____ or _____, what is the drug of choice?

Vivax or ovale; Primaquine phosphate