Aetiology, Mechanism, Management of Antibiotic Associated Diarrhoea and Role of Probiotics

With the increasing use of antibiotics, self medication and easy availability of antibiotics over the counter, the number of potential victims of Antibiotic associated diarrhoeas (AAD), either in its mild form or serious sometimes fatal disorder may be a force to reckon with. Understanding the pathogenesis, high risk factors and means of prevention may help us rto avert or effectively treat this disorder. Antibiotic associated diarrhoea is caused by Clostridium difficile, Clostridium perfringens, Staphylococcus aureus, Klebaiella oxytoca, Candida spp and Salmonella spp. Nearly 25% AAD is caused by Clostridium difficile making it the commonest identified and treatable pathogen. Most mild cases of AAD are due to non-infectious causes which include reduced break down of primary bile acids and, allergic or toxic effects of antibiotic on intesrtinal mucosa and pharmacological effect on gut motility. The antibiotics most frequently associated with C. difficile associated diarrhoea are clindamycin, cephalosporin, ampicillin and amoxycillin. The most sensitive and specific diagnostic tesrt for C. difficile infection is tissue culture assay for cytotoxicity of toxin B. Commercial ELISA kits are available. Most of the times, discontinuation of the inciting antibiotic along with enteric precautions and isolation to prevent its spread, is sufficient. However at times, treatment with antibiotics like metronidazole, vancomycin may be required. Relapses may occur which may require re-therapy with metronidazole/vancomycin, or at times treatment with anion binding resins and probiotics. Probiotics have been shown to have a role in the prevention of AAD {recurrent cases}. In recent years, AAD has been increasing in frequency and severity due to the emergence of virulent strains.