Sodium polystyrene sulfonate (SPS, Kayexalate) has been used for decades to help lower potassium levels and manage hyperkalemia. It does this by exchanging sodium ions for potassium ions in the gut (primarily the large intestine). The compound is then removed from the body out through the stool. It has some risks and controversy associated with its use that begs the question, should SPS ever be used?
From a polypharmacy perspective, I would strongly encourage you to review the medication list prior to considering an agent to reduce potassium levels. I’ve seen numerous cases where medications that can cause hyperkalemia have been overlooked, or not reported by patients. I’ve outlined 7 common medication causes of hyperkalemia in a previous post.
With regard to SPS, first and foremost, there is a significant adverse effect that can occur from the use of this medication. While not common, there has been a demonstrated risk of intestinal necrosis (great board exam question!). This risk appears more elevated when used with sorbitol. Patient risk factors for this adverse effect include GI disorders such as constipation, ileus, Ulcerative colitis, etc. Other potassium-binding medications do not seem to carry this same risk.
In addition to the possible serious adverse effect of intestinal necrosis, questions have been raised as to how effective the medication is at treating hyperkalemia. In this letter to the editor several years ago, serious questions have been raised as to how beneficial the medication is as well as the risk that may be encountered when using this medication.
Lastly, we have newer options available. Sodium zirconium cyclosilicate (SZC) and patiromer are relatively newer agents that can be used to help effectively lower potassium levels. We previously did a deep dive and provided some comparisons between cation exchangers in the management of hyperkalemia that you need to review.
The situations I can think of where SPS would be considered would be situations of drug shortages or limited access to some of the newer agents and other modalities to manage hyperkalemia.
What do you think, should SPS ever be used in favor of newer options?
Did you enjoy this blog post? Subscribers are emailed new blog posts TWICE per week! In addition, you’ll get access to the free giveaways below. Over 6,000 healthcare professionals have subscribed for our FREE Giveaways. Why haven’t you?!
- 30 medication mistakes PDF
- 18+ Page Drug Interaction PDF
- 10 Commandments of Polypharmacy Webinar based on my experiences in clinical practice