Discussions that mention klor-con

High & Low Blood Pressure board

I am taking a diuretic known as Furosemide.

As is common with loop diuretics, I have also been Rx'd a potassium supplement Klor-con. Suddenly the Klor-con was changed to Klor-con ER, the Extended Release formulation.

Is this the doctor's error? Is it serious?

I believe Furosemide although highly variable in individuals does its work within two hours and that the Klor-con ER would therefore likely be ineffective.

Anyone have any data or thoughts on this?
Note: I seem to have a vague recollection of having read a warning about this somewhere but I can't recall where and have not been able to find it by searching through anything readily at hand.