Amoebiasis Clinical Case 10

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AmoebiasisClinical Case 10

• Ellen Marie de los Reyes

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• EF, a fresh college graduate, is applying for a
  job at a pharmaceutical company. Routine
  laboratory examinations were requested. Fecalysis
  revealed () E histolytica cyst. Patient is
  asymptomatic.

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1. Give your Diagnosis
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Amoebiasis

• An infection with Entamoeba histolytica produced
  by the ingestion of cysts in the organism
• In the intestines, the cysts develop into
  trophozoites that adhere to colonic epithelial
  cells by means of a lectin on the parasite

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Amoebiasis

• Lyses the host cell
• invades the submucosa and secretes IFN-?
  activated macrophages
• This will result in dysentery
• The parasite can invade the liver and can develop
  liver abscesses and an amoebic granulomas
  developing in the intestinal wall

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Symptoms

• gastrointestinal including diarrhoea, vomiting,
  abdominal pain or discomfort and fever.
• Duration few days to a few weeks but usually it
  is about two to four weeks.
• Most are asymptomatic
• has the potential to make the sufferer
  dangerously ill
• Infections that sometimes last for years may be
  accompanied by
• no symptoms (in the majority of cases),
• vague gastrointestinal distress,
• dysentery (with blood and mucus).

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Asymptomatic Infection

• the amoeba lives by eating and digesting bacteria
  and food particles in the gut.
• It does not usually come in contact with the
  intestine itself due to the protective layer of
  mucus that lines the gut.
• Disease occurs when amoeba comes in contact with
  the cells lining the intestine.
• secretes toxic substances, including enzymes that
  destroy cell membranes and allow it to penetrate
  and digest human tissues, resulting in
  flask-shaped ulcers in the intestine.

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Amoebiasis

• Amoebiasis is transmitted
• fecal contamination of drinking water foods
• direct contact with dirty hands
• sexual contact

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2. How would you manage this case?
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Main drugs

• Metronidazole
• Tinidazole
• Diloxanide
• These agents may be used in combination

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Drugs of choice for various forms of Amoeboisis

• Acute invasive intestinal amoeboisis resulting in
  acute severe amoebic dysentarygt metronidazole
  followed by diloxanide
• Chronic intestinal amoeboisisgtdiloxanide
• Heptic amoeboisisgtmetronidazole followed by
  dilxanide
• Carrier stategtdiloxanide

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3. Discuss the pharmacokinetics of the drug of
choice.
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Metronidazole

• Kills the trophozoites of E. histolytica by
  damaging the DNA by toxic oxygen products
  generated by thedrug
• But has no effect on the cysts
• Most effective drug available for invasive
  amoebiasis

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Pharmacokinetics

• Usually given orally
• Rapidly, completely absorbed
• Peak plasma concentration 1-3 hrs
• Half-life 7 hrs
• Distributed rapidly through the tissues reaching
  high concentrations in the body fluids and CSF
• Some are metabolized and most excreted in urine

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Unwanted effects

• Bitter taste in the mouth
• Minor gastrointestinal disturbances
• Dizziness, headache, sensory neuropathies
• Drug interferes with alcohol metabolism

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Tinidazole

• Similar to metronidazole
• Eliminated more slowly
• Half-life 12-14 hrs

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Diloxanide

• Effective against the non-invasive intestinal
  parasite
• Drugs have a direct amoebicidal action affecting
  the amoebae before encystment
• Given orally
• No serious adverse effects

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• And now we reached the end!
• Thank you!