Antimalarials

Question 1

Pyrimethamine

Answer 1

folate antagonist

• binds dihydrofolate reductase
• prevents formation of purines + pyrimidines
• leads to failure of nuclear division

USE
= treatment of uncomplicated, chloroquine resistant, P. falciparum malaria and toxoplasmosis

Question 2

Quinine

Answer 2

haem polymerase inhibitor

• inhibits parasite’s ability to break down + digest haemoglobin ==> parasite starves OR builds up toxic lvls of partially digested Hb
• can act as a blood schizonticide

N.B. less effective + more toxic than chloroquine

USE
= treat life-threatening infections caused by chloroquine-resistant Plasmodium falciparum malaria

Question 3

Artemether

Answer 3

peroxide antimalarial
forms toxic oxygen + carbon centred radicals in parasite food vacuole

• used in combo w lumefantrine

Question 4

Effects of Artemether

Answer 4

• reduces no. of malarial parasites

- provides rapid symptom relief