So what did the FDA do?

This is just a running series of potassium facts.

From Sterns' article on sodium polysterene sulfonate (Kayexalate) and its ineffectiveness for treating hyperkalemia:
Sodium polystyrene sulfonate (SPS), an ion-exchange resin designed to bind potassium in the colon, was approved in 1958 as a treatment for hyperkalemia by the US Food and Drug Administration, 4 years before drug manufacturers were required to prove the effectiveness and safety of their drugs.
From Watson's counter editorial on sodium polysterene sulfonate and that its reasonable safety and effectiveness:
When SPS resins were first introduced, dialysis was an in- frequent procedure, and loop diuretics were in development.
You mean loop diuretics had to be developed? There was a time before lasix? Mind blown.

More random potassium trivia. The risk of hyperkalemia in anuric dialysis patients rises twice as high if they are on ACEi or ARB. Colonic and skin potassium excretion?

This is the closest thing to proof I've seen for the old saw that hyperkalemia is better tolerated in dialysis patients.

From the same article, looking at recurrent episodes of hyperkalemia:
There were 70 individuals (0.21%) who had more than 20 events [in one year of reporting!, Only one episode per day allowed], and a greater proportion of these patients had CKD, ACE-I and/or ARB use, and diabetes than the general population with hyperkalemia.