anti-protozoa malaria_flashcards
What is malaria, and what are the five species of Plasmodium that cause it?
Malaria is a mosquito-borne parasitic disease caused by: 1. P. falciparum (most dangerous). 2. P. vivax. 3. P. malariae. 4. P. ovale. 5. P. knowlesi (less common).
What is malignant tertian malaria, and what species causes it?
Malignant tertian malaria is caused by P. falciparum, with a life cycle of 48 hours, and fever occurs every third day. It is the most dangerous type.
What is benign tertian malaria, and what species causes it?
Benign tertian malaria is caused by P. vivax. Its life cycle is 48 hours, with milder attacks than P. falciparum and characterized by relapses that may last up to 2 years.
Which species causes malaria with periodicity and relapses similar to P. vivax?
P. ovale, which is milder and more easily cured.
What species causes quartan malaria, and how long is its life cycle?
P. malariae, with a life cycle of 72 hours.
What is unique about malaria caused by P. knowlesi?
Fever occurs every 24 hours.
Which species of Plasmodium have a dormant hepatic stage (hypnozoites)?
P. vivax and P. ovale have a dormant (resting) hepatic stage, known as hypnozoites.
What are the 4-Aminoquinolines used in antimalarial treatment?
Chloroquine and Hydroxychloroquine.
What drugs fall under the category of Quinoline Methanol for antimalarial treatment?
Mefloquine and Quinine.
Name the three subcategories of antimalarial antifolates with examples.
a) Biguanides: Proguanil (Chloroguanide).
b) Diaminopyrimidines: Pyrimethamine.
c) Sulfonamides & Sulfones: Sulfadoxine, Dapsone.
What is the role of 8-Aminoquinolines in antimalarial treatment, and name an example?
Used for latent stage treatment. Example: Primaquine.
What are the ‘other’ antimalarial drugs used?
Tetracyclines (e.g., Doxycycline), Clindamycin, Halofantrine, Artemisinins, Atovaquone.
What is the pharmacokinetics (P/K) of Chloroquine?
Well absorbed and widely distributed. Concentrated in parasitized cells and tissues. Excreted in urine (70% unchanged, 30% as metabolites). Excretion is increased by acidification of urine.
What is the primary mode of action of Chloroquine?
a) Prevents polymerization of heme released from hemoglobin to hemozoin. b) The free heme lyses the parasite cell membrane, causing death. c) Concentrates in vacuoles and increases pH, reducing the parasite’s ability to utilize hemoglobin.
What contributes to resistance to Chloroquine?
Resistance appears due to: Increased efflux of the drug from parasite vesicles, decreased uptake, and increased metabolism of Chloroquine by the parasite. P. falciparum is resistant in many parts of the world.
