Kexelate – still an important agent in the management of hyperkalaemia

Sodium polystyrene sulfonate (Kexelate) is a synthetic resin that theoretically exchanges sodium ions for potassium ions in the gut, thereby increasing potassium excretion in stool.

Its use in the management of hyperkalaemia has been brought into question recently, following a warning issued by the FDA.1 Consequently, many emergency medicine clinicians have advised against its use in the management of acute hyperkalaemia. Studies demonstrating serum potassium-lowering properties are small and poorly designed.2 , 3 Case reports demonstrating gastrointestinal tract (GIT) complications deal almost exclusively with Kexelate-sorbitol combinations,4 which are not generally used in South Africa. Sorbitol alone has been demonstrated to cause GIT complications in rats, while Kexelate alone has not.5 Sterns et al. summed up the situation with this statement: ‘Clinicians must weigh uncontrolled studies showing benefit against uncontrolled studies showing harm.’6

As there is a lack of high-quality studies we are guided by anecdotal evidence and expert opinion. The Groote Schuur Hospital Renal and Emergency Units have been using Kexelate for decades in the management of hyperkalaemia in both acute and chronic kidney disease. They have found it to be an effective and safe medication, with no known cases of serious GIT side-effects to date.

It must be stressed that the serum potassium-lowering effects of Kexelate are delayed owing to the mechanism of action. In the acute management of hyperkalaemia other agents (insulin, glucose) are of more importance for immediate effect. However, Kexelate should be given to these patients with a view to lowering serum potassium over the next 24 hours, while dialysis is being instituted or considered. We recommend that Kexelate be avoided in patients with prolonged bowel transit time, as these individuals are most at risk of GIT perforation.

Bradley Griffiths, MB ChB, DA (SA)

Medical Registrar, C15 Emergency Unit, Groote Schuur Hospital, Cape Town

Thomas Crede, MB ChB, FCP (SA), Dip HIV Management, DTM&H

Senior Specialist and Head, C15 Emergency Unit, Groote Schuur Hospital, Cape Town

Correspondence to: B Griffiths (bpgriffiths@gmail.com)