Tymos and kidney function?

Posted by anewyorker @anewyorker, Aug 25 7:41am

Hi everybody,

I'm a 77-yr-old woman who's had osteoporosis for a long time. I started out on Fosamax, had a long (and stupid) medication holiday after about 8 yrs, then went on Prolia, which I took without complication for three years.

Last October I had a compression fracture of the L1 vertebra after tripping over my vacuum and landing on my spine. I began taking Tymlos in January and have basically been OK with it. I do get some side effects after the shot (sometimesheart racing, extra fatigue, and nausea), but I can live with that.

What I"m concerned about is that since going on Tymlos my kidney function has notably decreased, according to the most recent labs. BUN rose to 21 mg/dL from 15 in April, creatinine rose to .95 mg/dL from .84 and eGFR dropped to 62 from 72, both in February. My blood calcium level is 10, within normal limits. Albumin is unchanged and has been stable for years.

Obviously increasing age is a factor--I don't seem to be getting younger--but these changes are remarkable in such a short time. Creatinine is the only waste product that factors into eGFR.

I've searched but can't find anything online about any relationship between Tymlos and kidney function except in terms of elevated calcium levels possibly causing kidney stones, which is not my problem. Does anyone have any information on this?

I'm seeing my endocrinologist next week and of course will bring this up.

Thanks for your thoughts!

Interested in more discussions like this? Go to the Osteoporosis & Bone Health Support Group.

gently | @gently | Aug 25 10:07am

@anewyorker

windyshores | @windyshores | Feb 26 7:58am https://connect.mayoclinic.org/discussion/kidney-problems-while-taking-tymlos/
"Tymlos raises calcium levels for a few hours so make sure you test blood and urine before Tymlos.

It also lowers blood pressure for an hour or two which can affect testing for kidney filtration rates.

I would make sure to have a Cystatin C rather than a creatinine based GFR if you can: it is more stable."

There is an article somewhere about reducing the dose of Tymlos if it is affecting eGFR.

windyshores | @windyshores | Aug 25 11:30am

In reply to @gently "@anewyorker windyshores | @windyshores | Feb 26 7:58am https://connect.mayoclinic.org/discussion/kidney-problems-while-taking-tymlos/ "Tymlos raises calcium levels for a few..." + (show)

@gently that post of mine with its recommendation to "make sure to test blood and urine" and have a Cystatin C reflects my own experience and should have been written in that context only. I have a lowish creatinine based eGFR but my Cystatin C is better and my nephrologist told me it is more stable.

My calcium level was tested in blood before starting Tymlos along with a bunch of other standard blood tests. My urine was not tested. In some threads, people write about how their blood test was okay but not their urine calcium, and I should have referred to those people. I did not have a urine test. My blood calcium as at the high end of normal at 10.3 but I had no problems.

My understanding from my doctor was that Tymlos can cause kidney stones but not kidney damage. It is best to check this with a doctor.

Any time I catch slippage into giving medical advice, in any serious way, I contact the administrators and ask them to delete it. The post cited is borderline. If I could I would rewrite it.

I have never heard of reducing Tymlos to protect the eGFR. My doctors tell me the creatinine based eGFR is quite complicated and can be affected by many things, including low blood pressure, muscle loss- and that is why they do the Cystatin C for me. Perhaps @ gently can provide a link. The idea that Tymlos can reduce the e GFR might be needlessly alarming . A doctor with training on this could clarify.

anewyorker | @anewyorker | Aug 25 11:43am

Windyshores, that’s very interesting. I did turn up one journal article this morning, from 2019, that concludes that tymlos is safe for patients with various levels of kidney function impairment. So there you go.

The article is titled “Abaloperatide in patients with mild or moderate renal impairment : Results from the ACTIVE Phse 3 Trial.” The journal is. Urgent Medical Research and Opinion.

anewyorker | @anewyorker | Aug 25 11:44am

Current, not Urgent. Sorry.

windyshores | @windyshores | Aug 25 11:51am

In reply to @anewyorker "Windyshores, that’s very interesting. I did turn up one journal article this morning, from 2019, that..." + (show)

@anewyorker my creatinine-based eGFR dipped from 55 to 36 last fall. I had stopped Tymlos some time before. Now that it is tested more often, it really bounces around and is generally mid to high 40's. My GFR from Cystatin C has stayed stable in the low 50's. Nephrologist says the true value is probably somewhere in between.

I have low blood pressure which can throw off the creatinine based GFR, but I have always had low blood pressure. The kidney doctor checked for a cyst or infection in kidneys, did an echocardiogram (low heart function can also affect it) and basically theorized it might be my muscle mass loss. I also have lupus and high antibodies for scleroderma so damage from those was checked.

My kidneys were fine throughout my 2 years on Tymlos. I am only one person and we are all different so just sharing my experience. I still don't really know why mine dropped! I have been told to increase salt (low bp) and protein (muscles) which is the opposite of the usual kidney diet. Hope you can see a nephrologist! ps I have an L1 fracture too (and L2, L5, T12, T6, T4!) Having fractures may cause muscle loss since we don't lift and exercise as before!

anewyorker | @anewyorker | Aug 25 12:01pm

Windyshores, that’s quite a story. I’ve always had LBP - always did, and now I take a beta blocker to regulate superventricular tachycardia, which lowers it further. Never occurred to me that it might play a role in this business. OTOH, I’ve been taking it since 2015 and always had eGFRs in the 70s and 80s until now. So probably not a factor.