Common causes include kidney failure, hypoaldosteronism, and rhabdomyolysis. A number of medications can also cause high blood potassium including spironolactone, NSAIDs, and angiotensin converting enzyme inhibitors.There is no universally accepted definition of what level of hyperkalemia is mild, moderate, or severe. However, if hyperkalemia causes any ECG change it is considered a medical emergency due to a risk of potentially fatal abnormal heart rhythms and is treated urgently. Potassium levels greater than 6.5 to 7.0 mmol/L in the absence of ECG changes are managed aggressively. Several approaches are used to treat hyperkalemia. Other approved potassium binders in the United States include patiromer and sodium polystyrene sulfonate.Hyperkalemia, particularly if severe, is a marker for an increased risk of death. However, there is disagreement regarding whether a modestly elevated levels directly causes problems. One viewpoint is that mild to moderate hyperkalemia is a secondary effect that denotes underlying medical problems. Accordingly, these problems are both proximate and ultimate causes of death,

History
Regulatory
In the United States, regulatory approval of ZS-9 was rejected by the Food and Drug Administration (FDA) in May 2016, due to issues associated with manufacturing. On May 18, 2018, the FDA approved sodium zirconium cyclosilicate for treatment of adults with hyperkalemia.It was first practically synthesized by UOP in the late 1990s.
(reference -zirconium silicate and zirconium germate molecular sieves and the process of using the same, US Patent 5,888,472) the recognition of the unique ion exchange properties and the potential use to remove toxins from the body were identified shortly thereafter ("process for removing toxins from bodily fluids using zirconium or titanium microporous compositions, US Patent 6,332,985). References
Further reading
CADTH review

External links
"Sodium zirconium cyclosilicate". Drug Information Portal. U.S. National Library of Medicine.