A 52 year old woman is admitted to the hospital for treatment of community acquired pneumonia. She is started on Levofloxacin and Azithromycin. On day 5 she developed painless watery loose stools.

1. What is the cause for her diarrhea?
  1. Amebiasis
  2. Giardiasis
  3. Clostridium difficile infection
  4. Clostridium botulinum infection

Answer: The answer is (c). This woman has antibiotic associated diarrhea. It is frequently seen after systemic antimicrobial therapy in hospitalized patients. It is caused due to toxin production by clostridium difficile. Amebiasis and Giardiasis are more common in the community setting.

 

2. Her treatment includes all the following except

  1. Stopping Levofloxacin
  2. Metronidazole oral
  3. Vancomycin oral
  4. Metronidazole IV

Answer: The answer is (a). There is no need to stop the Levofloxacin in case of antibiotic associated diarrhea. The target of treatment should be to eradicate clostridium difficile for which the ideal drugs are oral metronidazole and oral vancomycin. In severe cases IV Metronidazole can be used. But IV vancomycin is not of value.

 

3. The investigation to clinch the diagnosis in this case would be:
  1. Stool culture for clostridium
  2. Blood culture for clostridium
  3. Stool for clostridium toxin A
  4. Stool for clostridium toxin C

Answer: The answer is (c). The diagnosis of clostridium difficile associated diarrhea is clinched by the presence of clostridium difficile toxin A in the stool. There is a slight possibility of false positive test result. In cases where treatment is refractory or if the toxin assay in the stool is negative but the clinical features suggest the diagnosis of clostridium difficile associated diarrhea, the stool culture may be performed. Blood culture is of no value.

 

4. In cases of antibiotic associated diarrhea which is refractory to Metronidazole and oral Vancomycin all of the following measures should be taken except

  1. Tapering dose of high dose oral vancomycin
  2. Cholestyramine
  3. Rifampicin
  4. Mupirocin oral tablets

Answer: The answer is (d). Recurrent and resistant clostridium difficile diarrhea is common. Well-established treatment regimens for this condition are lacking. Pulsed and tapered dose of vancomycin is used. Adjunctive therapy with oral rifampicin, bacitracin or toxin binding resins like cholestyramine is also used.

 

5. Which of the following measures have to strictly avoided in this condition.

  1. Anti motility agents
  2. Anti emetics as they are toxic
  3. Oral rehydration solutions as they can osmotically worsen the diarrhea
  4. Antibiotics, as they are the root cause for this problem

Answer: The answer is (a). Anti motility agents have to be avoided in this condition as they can cause retention of the toxin in the colon and thus cause toxic colitis. This can lead to toxic dilatation of colon and perforation.