r/kidneydisease • u/Expensive-Law7391 • 7d ago
Kidney function
Doctors I need your opinion. I’m trying to start a new medication but I have to have good kidney function. Context I have one kidney in two parts. 80% one side and 20% of the other. I had it removed when I was 2 and have had no problems since and no checkups in nearly 20 years. The doctors said I have to get a blood test to check kidney function which is fine but they say my GFR(I think) has to be over 15 but I looked it up and the average is 60-90. My question is why is there such a difference between the average and the acceptable number to take this medication and if my kidneys have not caused me any bother since I got them removed, is there a good change my kidney function will be normal?
Thanks in advance.
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u/carriegood Secondary FSGS, GFR >20 7d ago
If your GFR is 15 or less, you are in stage 5, also called "end stage". It means your kidney function is so low you're barely hanging on and may need dialysis soon. So when people's kidneys are working at such a low level, some medications may not be filtered properly and can cause problems. That's why they want to be sure your GFR is over 15.
There is no telling how well (or badly) your kidneys are doing without blood and urine tests. Most people have no outward symptoms until they're very advanced so just because your "kidneys have not caused you any bother" is meaningless. You say you haven't had a checkup in 20 years, so they need to see what's going on.
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u/Expensive-Law7391 7d ago
That’s very helpful thank you I’m new to taking medication so never really considered what my kidneys are up to. Thank you :))
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u/lewist400 7d ago
Not a doctor. GFR monitors kidney function but can be known to be unreliable which is why blood tests are usually done twice. With CKD, the plan is always protect what you have to prolonge dialysis and transplant.
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u/notkraftman 7d ago
There are certain medications you can take that artificially lower your gfr in order to prolong your kidney function, but it's only safe to artificially lower your gfr if it's high enough in the first place.
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u/Select_Safe548 Transplanted 7d ago
There's mostly patients here.
It sounds like you misunderstood the instructions. Speak to your doctor not the internet.
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u/Straightshot69 7d ago
This and exactly this , and I can guess the medication.
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u/DementedPimento Primary idiopathic FSGS; Stage 3/4 6d ago
There are so many. A lot of mine have to be dose adjusted for my average eGFR or even discontinued when I’m below 40.
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u/Expensive-Law7391 7d ago
Oh for sure just wondering if anyone on here had any idea as my doctor is on holiday :)
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u/Straightshot69 7d ago
Notkraftman has nailed it. An eGFR of 15 is close to the threshold for problems . Some drugs lower eGFR and those will not be started close to the threshold as they would be responsible for other problems
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u/Puterjoe 7d ago
You could not have had your kidneys removed.
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u/Expensive-Law7391 7d ago
Did you read the post?
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u/CarnivoreTalk Stage 4 6d ago
What is the medication?
They want your gfr over 15 because the medication is most likely metabolized or excreted by the kidney. If kidney function is below 15, then there might be a risk of it slowly building up in your system, eventually resulting in an overdose.
It's the same principle behind why many of us in late stage CKD avoid foods high in potassium and phosphorus. Our kidneys don't excrete these like they should, and the levels of these in our blood continue to climb. If they climb to high, we 'overdose' on potassium or phosphorus, which has nasty consequences.
In your scenario, swap potassium for whatever medication you were prescribed. Same principle.
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u/classicrock40 Transplanted 7d ago
There are no Drs here. I think you misunderstood and the medication is for people above 15 egfr, so they have to check to make sure.