ORG MED Q3 LEC FINALS

Which Plasmodium species is characterized by fever recurring every 24 hours and is the most common cause of malaria in Southeast Asia, especially Malaysia?

• Plasmodium falciparum

• Plasmodium vivax

• Plasmodium knowlesi

• Plasmodium malariae

In the malaria life cycle, what is the stage called when merozoites first infect red blood cells and start feeding?

• Sporozoite

• Gametocyte

• Schizont

• Trophozoite

Which stage of the malaria parasite is targeted by primaquine as a radical cure?

• Sporozoite and schizont hepatic stages only

• Only erythrocytic trophozoite stage

• Both exo-erythrocytic (liver) and gametocytic stages

• Only gametocytes inside red blood cells

What is the toxic byproduct produced when the Plasmodium parasite metabolizes hemoglobin, which quinine disrupts from being detoxified?

• Hematin

• Tetrahydrofolate

• Heme-oxygenase

• Ferritin

Which stereochemical centers on quinine are crucial for its antimalarial activity, and what is the effect of modifying the C9 hydroxyl group?

• C2, C4, C6, C7; Modifications improve activity

• C3, C4, C8, C9; Modification reduces activity

• C1, C5, C8, C10; Has no effect

• C3, C5, C8, C9; Modification enhances toxicity

Hydroxychloroquine differs from chloroquine primarily by what structural modification, and how does this affect its pharmacokinetics?

• Addition of a chlorine atom on C7; shorter half-life

• Hydroxyl group on the N-ethyl side chain; longer half-life in the body

• Removal of the quinoline ring; more toxic

• Addition of trifluoromethyl groups; poorer absorption

Which antimalarial drug is associated with neuropsychiatric adverse effects such as seizures, and what is a key functional group responsible for this drug’s uniqueness?

• Chloroquine; Chlorine at C7

• Primaquine; Peroxide group

• Mefloquine; Trifluoromethyl moieties at 2’ and 8’

• Lumefantrine; Lipophilic side chains

In the malaria parasite’s life cycle, which of the following statements about gametocytes is FALSE?

• Male gametocytes are targeted by some anti-malarial drugs to block reproduction

• Gametocytes infect red blood cells before mosquito uptake

• Gametocytes develop within the liver cells

• Gametocytes are picked up by female anopheles mosquitoes during a blood meal

Which antimalarial agent is the natural product isolated from Artemisia annua and features a unique endoperoxide bridge essential for its activity?

• Quinine

• Artemisinin

• Pamaquine

• Halofantrine

Which combination drug inhibits the reduction of folic acid to tetrahydrofolate, crucial for Plasmodium DNA synthesis?

• Sulfadoxine and Pyrimethamine

• Atovaquone and Proguanil

• Chloroquine and Hydroxychloroquine

• Artemether and Lumefantrine