Drug-induced diarrhoea

Diarrhoea is a relatively frequent adverse event, accounting for about 7% o f all drug adverse effects, More than 700 drugs have been implicated in cau sing diarrhoea; those most frequently involved are antimicrobials, laxative s, magnesium-containing antacids, lactose- or sorbitol-containing products, nonsteroidal antiinflammatory drugs, prostaglandins, colchicine, antineopl astics, antiarrhythmic drugs and cholinergic agents. Certain new drugs are likely to induce diarrhoea because of their pharmacodynamic properties; exa mples include anthraquinone-related agents, alpha-glucosidase inhibitors, l ipase inhibitors and cholinesterase inhibitors. Antimicrobials are responsi ble for 25% of drug-induced diarrhoea. The disease spectrum of antimicrobia l-associated diarrhoea ranges from benign diarrhoea to pseudomembranous col itis. Several pathophysiological mechanisms rue involved in drug-induced diarrhoe a: osmotic diarrhoea, secretory diarrhoea, shortened transit time, exudativ e diarrhoea and protein-losing enteropathy, and malabsorption or maldigesti on of fat and carbohydrates. Often 2 or more mechanisms an present simultan eously. In clinical practice, 2 major types of diarrhoea are seen: acute diarrhoea, which usually appears during the first few days of treatment, and chronic diarrhoea, lasting more than 3 or 4 weeks and which can appear a long time after the start of drug therapy. Bath can be severe and poorly tolerated, In a patient presenting with diarrhoea, the medical history is very importa nt, especially the drug history as it can suggest a diagnosis of drug-induc ed diarrhoea and thereby avoid multiple diagnostic tests. The clinical exam ination should cover severity criteria such as fever rectal emission of blo od and mucus, dehydration and bodyweight loss. Establishing a relationship between drug consumption and diarrhoea or colitis can he difficult when the time elapsed between the start of the drug and the onset of symptoms is lo ng, sometimes up to several months or years.