To Pee or Not to Pee: Diuretics in CKD

Yeah, absolutely right.

And I know that we often see in our primary care or our acute services, patients who were getting these important medicines, having them stopped, which then makes them in fact more unwell with increasing breathlessness or increasing edema, for example.

We see the patients on the wrong diuretic dose when they have CKD.

And finally, we know there are lots of concerns that the diuretics may be causing or worsening kidney disease.

So altogether, it's an area of uncertainty, particularly in primary care, which I hope that we can clarify a little bit more about in the next 15 minutes.

Yeah, clarify, Andrew, and not cause confusion.

That's our aim, isn't it? So I'm going to kick off with a really important fact, that fundamentally, diuretics do not cause kidney failure or chronic kidney disease, or only extremely rarely.

and they're not associated overall with the worsening or progression of chronic kidney disease.

And there are loads of studies out there showing that the most recent actually, and one of the largest was from California, very recently looking at 50,000 people with GFRs between 15 and 50 mils per minute, so chronic kidney disease.

And in that large cohort, neither the initiation of diuretics, nor continuation of diuretics, nor the type of diuretic, was associated in any way with chronic kidney disease progression or end-stage kidney disease after accounting for their underlying disease and their comorbidities.

So the diuretics were not the cause of any problems in a very large pool of people with chronic kidney disease.

That's a pretty strong start, Jeremy, and pleased you've highlighted that and reassured people.

But it is, of course, as long as these agents are used appropriately.

And Jeremy, I'm sure you'd agree that if used incorrectly, they can cause deterioration in kidney function simply by causing volume depletion.

And that is often the fear that many primary care clinicians have when they start these medicine.

And that paranoia is perhaps reinforced by the fact that we do know that if the patient starts a diuretic, their GFR often falls a bit, doesn't it, as their circulating volume changes.

That's exactly right, Andrew.

Both the bits of that sentence you just said.

Sure, if the patient's volume decreases too much, then, of course, they essentially get dehydrated.

And a small drop is what we're trying to achieve, is their volume overloaded patients.

So that's right.

Diuretic use in patients who are volume depleted is inappropriate and that can cause significant acute kidney injury, a kidney problem, but not when the patient's volume overloaded and we're trying to get them back down to the right volume.

In that setting, small drops in GFR are often seen and are not a problem.