Comparison of Potassium Binders in the ER (KBindER)

Compare efficacy of 3 oral potassium binders (cation exchange resins) on lowering blood potassium, in hospital patients with acute hyperkalemia.

Adult patients presenting to the Emergency Room or currently hospitalized at UC Irvine (not in ICU level of care) with plasma potassium >5.5 mEq/L (who meet inclusion/exclusion criteria and provide written informed consent) will be randomized to a one-time dose of one of the following oral medications: Sodium polystyrene sulfate (SPS) Patiromer (Veltassa) Sodium zirconium cyclosilicate (Lokelma) Nonspecific laxative: polyethylene glycol 3350 (MiraLax) Participants will receive standard-of-care hyperkalemia therapy as well. Blood potassium will be checked at 2 and 4 hours after dose of study drug. Participants will complete a symptom and palatability questionnaire at 4 hours. The purpose of this research study is to determine the effects of various potassium binders (SPS, patiromer, zirconium) vs a non-specific laxative (MiraLax) in hospital patients found to have elevated blood potassium > 5.5 mEq/L. Hyperkalemia is a fairly common electrolyte disorder with varying levels of severity. Moderate hyperkalemia is in the range 5.5-5.9 mEq/L while severe hyperkalemia is ≥6.0 mEq/L or if patient is symptomatic: muscle weakness/paralysis or with EKG changes (e.g., peaked T waves, widening QRS, arrhythmias including ventricular fibrillation or asystole). Hyperkalemia is most commonly associated with kidney insufficiency, metabolic acidosis, and the use of medications such as renin-angiotensin-aldosterone system inhibitors. In an emergency, the main goal is to reverse adverse cardiac effects and shift potassium into cells using interventions such as insulin/glucose and albuterol. However, these are only temporary measures. To remove potassium from the body, agents or interventions that may be used include cation exchange resins (potassium binders), loop diuretics, or dialysis. For over 50 years the only available oral cation exchange resin has been sodium polystyrene sulfonate. In recent years, two new agents (patiromer and zirconium) have been approved by the FDA for chronic management of hyperkalemia. The cation exchange resins have not been studied head-to-head for acute hyperkalemia. This is a critical knowledge gap since acute hyperkalemia poses a significant burden on the healthcare system. In claims data analysis of 80,000 patients, half with hyperkalemia and half without, the patients with hyperkalemia had 4 times higher rate of inpatient admissions, 7 times longer average length of stay, and 30-day hospital readmission rate 14.21% vs 9.86% in the non-hyperkalemia cohort. The findings from our study will help inform decision-making guidelines for the treatment of acute hyperkalemia.

Participants will be randomized to one of four study arms. They will receive one dose of the study drug. One study arm is the nonspecific laxative MiraLax (one dose of 17g). Since constipation can contribute to hyperkalemia, this arm will study the effect of treating constipation instead of direct cation exchange for potassium in the gut.

Participants will be randomized to one of four study arms. They will receive one dose of the study drug. The potassium binder drugs of interest include sodium polystyrene sulfonate (one dose of 30g), patiromer (one dose of 25.2g), and sodium zirconium cyclosilicate (one dose of 15g).

Participants will be randomized to one of four study arms. They will receive one dose of the study drug. The potassium binder drugs of interest include sodium polystyrene sulfonate (one dose of 30g), patiromer (one dose of 25.2g), and sodium zirconium cyclosilicate (one dose of 15g).

Participants will be randomized to one of four study arms. They will receive one dose of the study drug. The potassium binder drugs of interest include sodium polystyrene sulfonate (one dose of 30g), patiromer (one dose of 25.2g), and sodium zirconium cyclosilicate (one dose of 15g).

The investigators will compare the change in blood potassium after administration of the study drug, in the acute setting.

The investigators will compare length of ER or hospital stay associated with each study drug, obtained from medical chart review.

The investigators will compare the effect of each study drug on blood calcium, phosphorus and magnesium levels, in the acute setting.

The investigators will assess whether dialysis was needed to manage hyperkalemia, and whether dialysis requirement was affected by the study drug given. This will be assessed from medical chart review.

Participants will complete a 1-page brief survey assessing for potential study drug side effects including bloating, nausea, diarrhea and palpitations (answers are yes/no). Participants will also rate the palatability of the study drug using a 1-5 scale, with 5 being the best score (most palatable and easy to swallow).

Inclusion Criteria: Plasma potassium > 5.5 mEq/L Age ≥18 years Patient able to provide written informed consent Exclusion Criteria: Recent bowel surgery Ileus or bowel obstruction Pseudohyperkalemia signs and symptoms, such as excessive fist clenching, hemolyzed blood specimen, severe leukocytosis or thrombocytosis Pregnancy Active psychiatric disorder Diabetic ketoacidosis or hyperkalemia caused by any condition for which a therapy directed against the underlying cause of hyperkalemia would be a better treatment option Dialysis session expected within 4 hours after randomization History of hypersensitivity to sodium polystyrene sulfonate resin or patiromer Concurrent use of sorbitol (due to increased risk of intestinal necrosis when used with sodium polystyrene sulfonate)

IPD will not be shared. De-identified dataset can be made available to other researchers, please contact PI Dr. Lau.

Leon SJ, Harasemiw O, Tangri N. New therapies for hyperkalemia. Curr Opin Nephrol Hypertens. 2019 May;28(3):238-244. doi: 10.1097/MNH.0000000000000500.

Betts KA, Woolley JM, Mu F, Xiang C, Tang W, Wu EQ. The Cost of Hyperkalemia in the United States. Kidney Int Rep. 2017 Nov 14;3(2):385-393. doi: 10.1016/j.ekir.2017.11.003. eCollection 2018 Mar.