Plasmodium Treatment

Question 1

Chloroquine phosphate

Answer 1

•Safe, low-cost, rapidly absorbed via oral route. Specific uptake by the
parasite, accumulates in food vacuoles
•Highly effective for blood schizonticide, but not effective for liver stage
parasites, moderately gameticidal
•Does not eliminate hypnozoites of P. vivax and P. ovale
•Prevents polymerization of Hb breakdown and lead to intracellular
accumulation of heme that is toxic to parasite
•Drug resistance is associated with P170 glycoprotein mutation

Question 2

Quinine and Quinidine (cinchona tree)

Answer 2

•First line drugs for P. falciparum, highly effective blood schizonticide
against all four types of plasmodia, gameticidal against P. vivax and P.
ovale, not active against liver parasites
•Complexes with double stranded DNA to prevent DNA replication and RNA
transcription RNA

Question 3

Mefloquin

Answer 3

•Recommended for chloroquine-resistant strains of P. falciparum, Strong blood
schizonticide against P falciparum and P vivax, but not active against hepatic
stages or gametocytes. The mechanism of action is unknown.

Question 4

Primaquin

Answer 4

•Effective against liver stage of all four species of plasmodia, effective for
hypnozoites of P vivax and P ovale, Gametocidal against all four species of
plasmodia, weak blood schizonticidal activity
•It forms quinoline-quinone metabolites that act as cellular oxidants.
•Often used in combination with a blood schizonticide, chloroquine

Question 5

Atovaquone

Answer 5

•A quinine derivative. Malarone, a combination of atovaquone and proguanil,
is highly effective for both the treatment P. falciparum malaria.
•Disrupt mitochondrial electron transport.

Question 6

Pyrimethamine and Proguanil

Answer 6

•Act against erythrocytic forms of all four human malaria. Not effective against
the persistent liver stages of P vivax or P ovale.
•Inhibitors of Folate synthesis

Question 7

Amodiaquine

Answer 7

•Closely related to chloroquine, low cost. May through the same mechanism as
chloroquine

Question 8

Artemisinin, artemether, dihydroartemisinin

Answer 8

-Contain endoperoxide
• In the presence of intra-parasitic iron, artemisine is converted into free radicals and other electrophilic intermediates which then alkylate specific malaria target proteins. Also through ATP inhibition
• World Health Organization lists amodiaquine plus artesunate as a recommended therapy for chloroquine resistant falciparum malaria in underdeveloped countries

Question 9

Antibiotics

Answer 9

• Tetracycline.
• Doxycycline.
• Clindamycin.
• Azithromycin.
• Fluoroquinolones.
Active against erytrocytic forms of all species.
Usually for chloroquine-resistant strains