HYPERKALEMIA AND DIARRHEA IN A PATIENT WITH SURREPTITIOUS INGESTION OF POTASSIUM SPARING DIURETICS

We report a patient who presented with the unusual combination of chro nic diarrhoea and hyperkalaemia. The patient was admitted to our hospi tal after repeated negative evaluations elsewhere including explorator y laparotomy. The patient had a long history of diarrhoea with hypokal aemia which was documented on several occasions in the past. Several m onths before admission to our hospital for evaluation of diarrhoea the patient developed hyperkalaemia. Her daily stool output reached 1200 g and her serum potassium was as high as 6.0 mmol/l. Extensive evaluat ion revealed surreptitious ingestion of the diuretics triamterene, hyd rochlorothiazide and spironolactone as the cause of hyperkalaemia and diarrhoea. In addition, she had melanosis coli which was interpreted t o be the consequence of surreptitious ingestion of anthraquinone-conta ining laxatives in the past although no current laxative intake could be proven. We postulate that diarrhoea in our patient was mainly due t o the decreased sodium absorption in the small intestine and colon cau sed by diuretics. Serum aldosterone levels were more than eight times the upper limit of normal. Increased aldosterone levels presumably aro se secondary to volume contraction and sodium chloride depletion, but presumably were not able to affect renal and colonic electrolyte trans port because of blockage of mineralocorticoid receptors by spironolact one. Thus, the unusual combination of diarrhoea and hyperkalaemia resu lted.