Acute CHF exacerbations and CKD (why Bumex over Lasix)

[DrMetal]

Riddle me this: Why do we seem to prefer Bumex (over Lasix) as the agent of diuresis during an acute CHF exacerbation (in a patient with CKD, perhaps an acute AKI).

We know Bumex is more potent and it's bioavailability is higher than that of Lasix, but all that means is you can give a lower dose of Bumex (1-2 mg), vs the 20-40mg of Lasix. Ok, I know psychologically we feel better for giving the lower dose medication . . . but that aside, is there really any reason to give Bumex over Lasix? (they both work the same, loop diuretics, right?).

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[bobow98]

when there is severe CHF you get gut edema - this means poorer Lasix absorption probably.
We used to do torsemide as the preferred oral agent during my residency for the severe CHF folks and didn't use much bumex. Perhaps the uptodate page on cardiorenal might shed some light for you.
What do I know, I'm a simple oncologist. 🤷‍♂️

 

[DrMetal]

when there is severe CHF you get gut edema - this means poorer Lasix absorption probably.
We used to do torsemide as the preferred oral agent during my residency for the severe CHF folks and didn't use much bumex. Perhaps the uptodate page on cardiorenal might shed some light for you.
What do I know, I'm a simple oncologist. 🤷‍♂️

yeah, torsemide is a good choice for PO. Not sure why we don't use it as much.

what about IV Bumex vs IV Lasix? I see a lot of nephrologists preferring the IV Bumex. Literature doesn't seem to tout Bumex so much over Lasix (IV forms). pricewise: a 1-2 mg dose of IV bumex = ~$7-10 (using the lexicomp pricing, i dunno if accurate). 40 mg IV lasix about the same, maybe a little cheaper.

 

[NITRAS]

Where I did residency, we all used Bumex. Where I currently work, most of the cardiologist prefer torsemide. Both torsemide and Bumexa have superior bioavailability when your patient is volume up.

If you are using IV, it doesn’t matter and Lasix is cheaper. . . . At least that is what I have been told. It really isn’t that big of a deal. Nothing I’d argue with a cardiologist or nephrologist about.

 

[Drrrrrr. Celty]

yeah, torsemide is a good choice for PO. Not sure why we don't use it as much.

what about IV Bumex vs IV Lasix? I see a lot of nephrologists preferring the IV Bumex. Literature doesn't seem to tout Bumex so much over Lasix (IV forms). pricewise: a 1-2 mg dose of IV bumex = ~$7-10 (using the lexicomp pricing, i dunno if accurate). 40 mg IV lasix about the same, maybe a little cheaper.

It's all culture and familiarity. They all do the same thing. And in the end switching from bumex iv to bumex po doesn't make my interns have to think too hard.

 

[Chemist0157]

There's not much difference. Lasix response can be more variable than Bumex. I remember in fellowship one of the other fellows presented one study that did show some marginal benefit of Bumex compared to Lasix, but I can't find it. I believe it was based on the notion that Lasix is more reliant on albumin for delivery to the tubule compared to Bumex or torsemide.

 

[DrMetal]

If you are using IV, it doesn’t matter and Lasix is cheaper. . . .

That's what I thought. I often wonder why the nephrologists change my IV lasix to IV bumex (I don't argue the point, was just curious).

There's not much difference. Lasix response can be more variable than Bumex. I remember in fellowship one of the other fellows presented one study that did show some marginal benefit of Bumex compared to Lasix, but I can't find it. I believe it was based on the notion that Lasix is more reliant on albumin for delivery to the tubule compared to Bumex or torsemide.

Interesting, I couldnt find anything either. If that albumin association is true, I'd understand. Many of these patients also have hypoalbuminemia.

 

[ROBINHO]

Lasix has bioavailability problems in the ORAL formulation. IV lasix has good bioavailability.
Decision on Lasix IV versus Bumex depends on so many factors such as home dose of diuretic, kidney function .
If a patient is on Lasix 40 mg Po BID and they come in with CHF exacerbation you can escalate to lasix 100 mg IV BID ( using the DOSE trial protocol). In such a patient you can use Bumex but no strong reason.
If a patient comes in CHF exacerbation while on Torsemide 100 mg PO BID at home ( = Lasix 100 mg IV BID --* some sources use a different conversion for IV ) , that tells me that the diuretic threshold needs to be higher. In such as case, makes more sense to consider IV Bumex. If creatinine is higher then may make sense to to use the more powerful medication.

There may be some preferences depending on what institution.

 

[DrMetal]

Lasix has bioavailability problems in the ORAL formulation. IV lasix has good bioavailability.
Decision on Lasix IV versus Bumex depends on so many factors such as home dose of diuretic, kidney function .
If a patient is on Lasix 40 mg Po BID and they come in with CHF exacerbation you can escalate to lasix 100 mg IV BID ( using the DOSE trial protocol). In such a patient you can use Bumex but no strong reason.
If a patient comes in CHF exacerbation while on Torsemide 100 mg PO BID at home ( = Lasix 100 mg IV BID --* some sources use a different conversion for IV ) , that tells me that the diuretic threshold needs to be higher. In such as case, makes more sense to consider IV Bumex. If creatinine is higher then may make sense to to use the more powerful medication.

There may be some preferences depending on what institution.

I guess I'm asking a pharmacology question: how does IV Lasix differ from IV Bumex?

The albumin point above seems to be supported in the literature:
The added-up albumin enhances the diuretic effect of furosemide in patients with hypoalbuminemic chronic kidney disease: a randomized controlled study - BMC Nephrology

So if hypoalbumin, and many ckd patients are, makes sense to prefer IV bumex.
(Or give some albumin with IV lasix)