Anti-malarials

Question 1

What is the population at risk to malaria?

Answer 1

3.3 billion (half the world population)

Question 2

What is malaria caused by?

Answer 2

Protozoan parasites of the genus Plasmodium. There are 5 species that infect man. Parasites are transmitted by females of Anopheles while taking blood.

Question 3

What 5 species infect man?

Answer 3

1. P. falciparum
2. P. vivax
3. P. malariae
4. P. ovale
5. P. knowlesi

Question 4

What is the Malaria life cycle?

Answer 4

Female injects sporozoites into blood.
Sporozoites go to liver.
Infection into RBC's
Merozoites form and burst
RBC's undergo asexual cycle
Gametocytes form and are passed on to the next mosquito

Question 5

What is the malaria control strategy?

Answer 5

• early diagnosis
• treatment with effective antimalarials
• selective use of preventative measures

Question 6

Why is Quinidine not used to treat malaria?

Answer 6

Because of its actions on the heart.

Question 7

What does Quinine do to treat Malaria?

Answer 7

Main alkaloid in bark. Active against erythrocytic stages of the parasites. Not clearly defined but:

• binds to DNA stopping synthesis of nucleic acids
• inhibition of haeme digestion

Question 8

What was one of the first synthetic antimalarials?

Answer 8

Pamaquine. (during WWI)

Question 9

What was Pamaquine active against?

Answer 9

Avian malaria (the model form), but now P. falciparum (the human form). It was toxic to humans.

Question 10

Name 8 synthetic antimalrials.

Answer 10

1. Chloroquine
2. Amodiaquine
3. Primaquine
4. Mefloquine
5. Pyronaridine
6. Proguanil
7. Sulfonamides
   * **8. Artemisinin Derivatives (need to use in combination to avoid resistance development)