Drugs and Parasites- Antihelminthics, malaria, anti-protozoal drug Flashcards
Give an example of antihelminthics.
Mebendazole- to treat threadworm (intestinal nematodes) and Giardiasis (cardia lambia)
What are the most common micro-organisms cause malaria?
Plasomodium sp., P falciparum, P. viral, P. malaria, P. ovale (rare)
State the four sites of actions for malaria drugs.
1) used to treat acute attack
2) for radial care (P. virax and P. ovale)
3) for chemoprophylaxis
4) to prevent transmission
State the four types of malaria drugs.
1) Rapid acting- Schizonticide
2) Slow acting- Schizonticide
3) Tissue Schizonticide
4) Gametocide
Examples of Rapid acting- Schizonticide.
Chloroquine, Quinine, Artemisinin, Artrmisinin Therapy (‘Riamet’: Artemether + Lumefantrine; ‘Eurartesim’: Artenimol + Piperaquine)
Examples of Slow acting- Schizonticide
1) Pyromethaine + Sulphadoxine
2) Proguanil
3) Malarone (Atovaquone + Proguanil)
4) Antibiotics eg. Doxycycline- protein synthesis inhibitor; Clindamycin
Drug example of Tissue Schizonticide. States it’s mechanism and S/E.
Primaquine- for free radical damage by inhibiting electron transport chain at mitochondria (Radical Curative Activity).
S/E: cause haemolysis of G6PD- lead to black urine, mild jaundice, life-threatening anaemia and renal failure.
Drug example of Gametocide.
Primaquine- for free radical damage by inhibiting electron transport chain at mitochondria (Radical Curative Activity).
S/E: cause haemolysis of G6PD- lead to black urine, mild jaundice, life-threatening anaemia and renal failure.
NOTE: low dose (0.25mg base/kg) no risk of haemolysis and G6PD risk
Name the type of malaria vaccine.
RTS1S/ASO1: pilot trial at 2018
What does Chloroquine use for?
it is a Rapid acting Schizonticide. It causes lysis of parasite and RBC, leading accumulation of ion trapping, thus, parasite digestive vacuole (pH 4.5).
Name the type of resistance of Chloroquine. And what will be prescribed next?
PdCRT- P. Falciparum Chloroquine Resistance Transporter.
Prescribed next: verapamil, and concanamycin A.
What is the mode of actions for Artemisinin?
free radical-induced protein damaged, leading inhibition of Ca2+ dependent ATP-ase.
What is the mode of action for Proguanil?
It is a folate antagonist that inhibits DHFR.
> for prophylactic use with chloroquine
> potentiate ‘atovaquone’ activity against P. falciparum.
What is the mode of action of ‘Malarone’ (Atovaquone + proguanil)?
it targets plasmodial mitochondria to inhibit pyrimidine biosynthesis.
