Anti Ameobic Drugs

Question 1

Classification

Answer 1

1. luminal amoebicides: Act on trophozites
   a. amides - Diloxanide furoate & nitazoxanide.
   b. 8-Hydroxyquinolines: Iodoquinol
   c. Antibiotics: Tetracyclines, paromomycin.
2. Tissue amoebicides:
   a. Nitroimidazoles: Metronidazole, timidazole
   b. Emetine group : Emetine, dehydroemetine
   c. 4-Aminoquinoline : Chloroquine

Question 2

Metronidazole

Answer 2

MOA- enters microorganisms and the nitro group of drug accepts electrons from ferredoxins which converts to highly reactive nitro radical which inturn damages microbial DNA. Results in death of organism.

Drug interactions:

1. Potentiates anticoagulant effect of warfarin
2. Prolongation of prothrombin time
3. Potentiates lithium toxicity by decreasing renal clearance

Uses:

1. Ameobiasis
2. Trichomonas vaginalis
3. Giardiasis
4. Anaerobic infections

Question 3

Treatment regimen for ameobiasis

Answer 3

1. For asymptomatic carriers:
   Luminal ameobicide is used.
   Diloxanide furoate/ paromomycin.
   Tab. Diloxanide furoate 500mg 10days
2. For intestinal ameobiasis:
   Metronidazole + Tinidazole + luminal agent

Tab. Metronidazole 400mg TDS
Tab. Diloxanide furoate 500mg TDS

3. For severe amoebic dysentery and extraintestinal ameobiasis:
   Metronidazole + luminal agent

Metronidazole 500mg i.v infusion for 6hrs

4. Hepatic ameobiasis:
   Chloroquine 500 mg BD for 2 days