AMEBIASIS

AMEBIASIS-TREATMENTS

Amoebiasis is caused by an organism known as Entamoeba histolytica a parasite resembles the water-bearing nonparasitic organism Amoeba.

The Life Cycle
The life cycle of this organism is composed of six stages as follows:-
1.Ingestion of cysts
2.Formation of trophozoites in the intestinal lumen
3.Trophozoites penetration into the intestinal wall
4.Trophozoites multiplication inside the colonic wall.
5.Invasion into the system
6. Infective cysts expelled in feces.
Amebicides are classified as follows:-
1.Mixed
These are active both against the internal and external of the system.e.g.Metronidazole (Flagyl)
2.Luminal
These are active at the extra systemic level that is at the luminal level.e.g.
1.Diloxanide Furoate(Furamide)
2.Paromomycin(Humain)
3.Iodoquinol(Diodoquin)
4.Tetracyclin  
3.Systemic
These are acting at a systemic level only. Not active on the lumen.e.g
1.Emetin
2.Dihydroemein
3.Chloroquine
Metronidazole (Mixed)
Metronidazole is generally toxic to amoebae, anaerobes anoxic/hypoxic cells
Action
Metronidazole is forming a cytotoxic compound which is formed by a redox reaction with the ferredoxin radical present in the nucleus of the parasite. 
Can be taken by oral or IV
Metronidazole is widely distributed in our body's all compartment including seminal, vaginal fluids, saliva, and brain system.
Metabolized in the liver. The metabolism is rapid if given with phenobarbital.
Side effects
1. Disulfiram like reaction happened if alcohol is consumed concurrently like flushing, tachycardia, nausea, thirst, chest pain, vertigo, and low blood pressure
2.Stomach pain, vomiting
3.Metallic taste
4.Warfarin synergism
5.Discoloration of urine
6.Dizziness, vertigo, numbness.
Metronidazole is not safe during pregnancy and lactation. It teratogenic
Dilaxonide Furoate (Luminal)
The action mechanism is unknown
Can be given oral only
It is 90% absorbed into the system
The unabsorbed portion is active inside the lumen
Used in combination with metronidazole to eradicate both systemic and luminal infections.
Side effects
1.Flatulence
2.Dry mouth
3.Pruritus
4.Urticaria
Paromomycin (Luminal)
It is an aminoglycoside antibiotic causes protozoal cell leakage. It also reduces the intestinal flora which is the food for the amoebae 
Can be given oral only
Not much absorbed systemically and hence more powerful than Diloxanide Furoate.
Side effects
GI distress
Diarrhea
Systemic absorption may result in headaches,rash, etc.
Iodoquinol(Luminal)
Used for asymptomatic amoebiasis only
Side effects
Headache
Fever
Diarrhea
Tetracyclin(Luminal)
It is not acting directly on the amoeba but destroying the intestinal flora and thereby devoiding of the amoeba's main food source.
Can be given by oral only
Dairy foods that contain calcium and antacids that contain aluminum and magnesium should not be given within one hour of the administration of tetracycline as they may reduce its absorption by forming chelates.
Children younger than 8 years and pregnant women should not be treated tetracycline.
Emetin and Dehydroemetin
They inhibit protein synthesis of the amoeba cell.
They distributed widely in the body tissues.
Long half-life.Slow excretion. It can be given by injection only.
Because of their severe toxicity these drugs are used only under doctor's supervision.
Side effects
1.Cardiotoxicities like arrhythmia and CHF
2.Neuromuscular weakness
3.GI distress
4.Dizziness
5.Rash
6.Pain at the injection site