Flashcards in Malaria Treatment - Regal Deck (14)
1
Suppressive Prophylactic Treatment
Malaria: Chloroquine
2nd: Atovaquone/proguanil
Chloroquine-Resistant Malaria: Atovaquone/proguanil
2nd: Doxycycline or Mefloquine
2
Clinical status of Severe Malaria Disease
Most deaths from severe malaria occur within the first 24-48 hours, so we need a parenteral therapy that acts quickly
3
Why is Primaquine considered the "radical cure"?
It acts on the latent hepatozoite Exoerythrocytic forms of P. vivax and P. ovale
4
What type of plasmodium have the most resistance to treatment?
P. vivax
P. falciparum
5
What type of plasmodium have a persistent hepatic form?
P. vivax
P. ovale
6
Atovaquone/Proguanil
Atovaquone
MoA: depolarizes parasitic mitochondria and inhibits their electron transport
Selectivity: plasmodial electron transport
Toxicity: drug interactions
Proguanil (metabolite of atovaquone)
MoA: inhibits DHFR
Selectivity: plasmodial enzyme DHFR; slow onset
Toxicity: GI disturbances
7
Chloroquine
MoA: Disrupts sequestration of heme as hemozoin; keeps heme in toxic form
Selectivity: parasitized RBC concentrates Chloroquine 25x more than unparasitized RBC and accumulated in the acidic pH of food vacuole
Toxicity: visual accommodation, large doses = blindness
8
Doxycycline
MoA: Inhibits protein synthesis by binding to the 30S ribosomal subunit
Selectivity:
Toxicity: Photosensitivity Rash
9
Mefloquine
MoA: unknown; may disrupt sequestration of heme as hemozoin
Selectivity: Unknown
Toxicity: Neuropsychiatric reactions, N/V
10
Primaquine
MoA: unknown; reactive oxygen species or interfering with electron transport in the parasite
Selectivity: unknown; eradicates hypnozoite forms dormant in liver
Toxicity: N/V, leukopenia, hemolytic anemia w/ G6PD
11
Quinine
MoA: unknown; may disrupt sequestration of heme as hemozoin
Selectivity: unknown; used in chloroquine resistant P. falciparum
Toxicity: More toxic than chloroquine; tinnitus, blurred vision, headache, nausea, damage to vision, balance and hearing
12
Quinidine
MoA: unknown; may disrupt sequestration of heme as hemozoin; blocks Na and K currents (a fib treatment)
Selectivity: unknown; used in chloroquine resistant P. falciparum; given IV
Toxicity: Cardiac problems
13
Artemisinins and combinations (ACT = artemisinin-based combination therapy)
MoA: Heme iron acts on drug to produce free radical to damage parasite proteins; inhibits Ca2+ ATPase in P. falciparum
Don't use Artemisinins alone to avoid forming resistance.
14