Can You Take Bumex And Lasix Together?
In our latest question and answer, our pharmacist discusses the problem of combining Lasix and Bumex.

Question
I’m taking bumetanide 1mg and furosemide 20 mg from 2 different doctors. Should I be taking both since they are both basically Lasix?

Answered by Dr. Brian Staiger, PharmD
Medical Content Reviewed By HelloPharmacist
Staff
Last updated Mar 29, 2025
Key points
- Bumex (bumetanide) and Lasix (furosemide) are both loop diuretics and are generally not combined together.
- If you have received prescriptions for both medications from different doctors, it is important to clarify with them or consult with your pharmacist to ensure the appropriate medication regimen. Therapeutic duplication should be addressed before taking both medications.
Quick Answer
Bumex (bumetanide) and Lasix (furosemide) are generally not combined as they are both loop diuretics. If you received prescriptions for these from two different doctors, be sure to speak with them to clarify or at the very least speak to your pharmacist so they can help clear up what your medication regimen is supposed to be.
Detailed Answer
As mentioned in the 'quick answer', Bumex and Lasix are both loop diuretics. In fact, Bumex is structurally related to Lasix but Bumex is about 40 times more potent on a milligram-to-milligram basis.
Loop diuretics, overall, have a similar effect on the body when given at equivalent doses. For instance, if a person with normal kidney function takes 40 mg of furosemide, it would be roughly the same as taking 1 mg of bumetanide.
Dosing does need adjusting in certain situations, however. For example, if someone has impaired kidney function, the ratio changes to around 20:1 for furosemide and bumetanide due to increased clearance of bumetanide outside the kidneys in these individuals.
Now, it would be very unlikely that two loop diuretics are used together but it's certainly not uncommon that diuretics from different classes are used together due to what is known as diuretic resistance.
Diuretic Resistance
Diuretic resistance is a common problem, especially in the treatment of severe congestive heart failure (CHF) when excess fluid builds up in the body.
Loop diuretics, like Bumex and Lasix, may become less effective over time due to an adaptation of a specific part of the kidney called the distal tubule. Studies in animals have shown that when loop diuretics are given, the distal tubule adapts by becoming more efficient at reabsorbing sodium.
This means that even with the diuretic, the kidneys still hold on to more sodium and water, leading to the persistence of fluid retention.
To overcome diuretic resistance, doctors have found that combining different types of diuretics can be helpful.
One effective combination is using a loop diuretic along with a thiazide diuretic (such as hydrochlorothiazide), which works on a different part of the kidney called the distal tubule. By targeting multiple areas, these diuretics can work together to enhance the removal of excess fluid from the body.
Use Of Lasix And Bumex
So, circling back here, while it's relatively common practice to use two different diuretics from different classes in certain situations, it's not common to use two from the same class (like Lasix and Bumex) since they work the same way, and in the same part of the kidney.
Without more information or context, it seems like you have a situation where two different doctors are prescribing the same kind of drug for your condition without communication with one other.
On the surface, it looks like a therapeutic duplication that should be addressed before you start taking both meds.
Final Words
Thanks for contacting us and I hope this helped!
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Dr. Brian Staiger, PharmD
- 1779 views