Diarrhoea metronidazole

Wilcox MH, Howe R Diarrhoea caused by Clostridium difficile Response time for treatment with metronidazole and vancomycin. J Antimicrob Chemother 1995,36 673-679. 

Antibiotic therapy is justified where there is suspicion of giardiasis (metronidazole) and bismuth subsalicylate is effective in acute travellers diarrhoea, as are agents such as ciprofloxacin. In tropical areas where there is suspicion of amoebic disease metronidazole should be given early. 

Adverse effects include nausea, vomiting, diarrhoea, myalgias and because of its serious side effects including cardiac arrhythmia, CHE and hypotension, they have been almost completely replaced by metronidazole. 

Clostridium difficile is a commensal Gram-positive anaerobic bacterium of the human intestine, found in about 2-5% of the population. C. difficile is the most serious cause of antibiotic-associated diarrhoea and can lead to pseudomembranous colitis, a severe infection of the colon, often resulting from eradication of the normal gut flora by antibiotics. Discontinuation of causative antibiotic treatment is often curative. In more serious cases, oral administration of metronidazole or vancomycin is the treatment of choice. The bacterium produces several known toxins, including enterotoxin (toxin A) and cytotoxin (toxin B), both of which are responsible for the diarrhoea and inflammation seen in infected patients another toxin, binary toxin, has also been described. 

Teasley DG, Gerding DN, Olson MM, Peterson LR, Gebhard RL, Schwartz MJ, Lee JT Jr. Prospective randomised trial of metronidazole versus vancomycin for Clostridium-difficile-associated diarrhoea and cohtis. Lancet 1983 2(8358) 1043-6. 

Colitis may result from various gut infections, especially amoebic colitis. Clindamycin, vancon cin or metronidazole may be used in treatment. The diarrhoea of colitis states may be treated with normal ANTIDIARRHOEALS, e.g. the opioids codeine, morphine, diphenoxylate and loperamide. The colic may respond to ANTISPASMODICS, e.g. the anticholinergics atropine, hyoscine, dicyclomine, propantheline. Meheverine is a direct-acting antispasmodic effective in some types of gut colic. 

Amoebiasis, due to infection with Entamoeba histolytica, is conveyed between humans by its cysts which are 10 microns in diameter. They survive well outside the body and are ingested in water and uncooked food. In the colon, the larger vegetative forms (trophozoites) emerge and cause chronic diarrhoea and, often, ulceration of the bowel wall. Unlike bacterial dysentery, this disease is seldom self-limiting without proper medication. Abscesses in the liver form a common complication. A ready cure can be effected with metronidazole (Section 6.3.3). 

Metronidazole is reduced xmder anaerobic conditions to a compound that prevents DNA synthesis. Adverse effects associated with metronidazole include nausea, diarrhoea, weight loss, abdominal pain, vomiting, headache, dizziness and metallic taste in the moutii. 

A 67-year-old woman with liver cirrhosis was treated with metronidazole (1.5 g daily) for Clostridium difficile associated diarrhoea [34 ]. She developed dysarthria and gait disturbance 27 days after initiation of treatment. Neurological examination showed ataxia, hypotonia and diminished tendon reflexes in the limbs. Electroencephalogram showed an 8-Hz backgroxmd a-rhythm with a small number of 9 bursts. Brain MRI revealed lesions in the cerebellar dentate nuclei and the splenium of the corpus callosum. The ataxic symptoms stopped after tiie discontinuation of metronidazole and follow-up MRI showed improvement of dentate lesion. 

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