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Do TKI's really cause magnesium loss?

I can't find the facts on this anywhere, yet I remember people saying the TKI's can mess with the body's absorption and metabolism of magnesium.  This, ostensibly, is what is behind the common side effect of muscle cramps.  I don't have those or any of the other symptoms of low magnesium, except for muscle weakness and fatigue.  I've investigated just about every possible reason for those, but have been wondering if malabsorption of magnesium might be it.  (I'm on dasatinib, btw.)  Does anyone have the science on this question?

Kat - do you take magnesium supplements now?

 

Some references:

http://www.ancient-minerals.com/magnesium-deficiency/causes-depletion/#m...

I was told by Dr. Cortes that Dasatinib can cause magnesium depletion.

 

Thanks, Scuba.  Did Dr. Cortes reference anything?   I just can't find any corroboration. 

No, I don't currently take any magnesium.  But I do take Sotalol, which is on the list of possibly causing this.  And Gleevec gave me abnormally high creatinine, which they are now thinking is a tubular "injury" of the imatinib.  Who knows. 

I guess I'll ask my PC if it's OK to supplement.  She won't be convinced I'm sure and I probably have a normal level and she won't buy it that that isn't defininitive.  Sigh.

Just in case anyone out there has high blood sugar levels due to diabetes, it turns out that high blood sugar levels can cause magnesium deficiency too.

My endocrinologist only mentioned this to me when I enquired about magnesium supplements to offset the loss from TKIs. No one ever mentioned it to me over the 38 years I've lived with diabetes, which in hindsight seems strange.

I'm just trying to take one tablet of MagMin per day. I've tried to find a magnesium taurate supplement like the one Scuba uses, which apparently is low on gastrointestinal side effects, but have had no luck tracking them down in Australia. Maybe I will order online...

Good luck Kat

Level of Magnesium in the blood does not reflect magnesium level in your muscles and tissues.

It is vital for the body to maintain electrolyte balance in the blood (PH control mostly). A deficiency in the blood can be life threatening. The body maintains blood levels by taking it from the muscles and tissues. And the blood only needs a few percent of total magnesium in the body. Blood tests are therefore misleading.

This is why a person can have perfectly fine blood levels and be very deficient in the muscles and organs. If your doctor does not know this, then time for a new doctor.

http://www.ancient-minerals.com/magnesium-deficiency/need-more/

Also - our food supply is losing magnesium. Plants is where we used to get our magnesium needs met easily -but modern farming has depleted the soils.

https://www.sciencedirect.com/science/article/pii/S221451411500121X

So even without taking a TKI - many in the population are in need of extra magnesium.

It's hard to overdose on Magnesium Your kidneys are very good at keeping it regulated. And a sure sign of too much magnesium long before it's a problem is diarrhea. No diarrhea - you're fine.

https://www.healthline.com/health/food-nutrition/magnesium-overdose-what...

I take between 250-500 mg per day. And have been doing this for years. No more muscle cramps or irregular heartbeats. My neighbor takes 800 mg of Magnesium per day for heart health reasons (family history of heart attacks).

Stay within this range of Magnesium and you will be fine.

A final thought - when an ambulance picks up a heart attack victim - the IV they put into you is a magnesium sulfate fluid. See link below to see why.

https://www.drwhitaker.com/request-a-magnesium-iv-for-heart-attack

This is a good link to add to those Suba has posted. Magnesium levels are pretty crucial to good health whether you take a TKI or not.

Sandy

http://www.nutritionalmagnesium.org/category/expert-articles/magnesium-deficiency-expert-articles/

Thanks, Sandy - I'll ask the docs.  I suppose it couldn't hurt to just take 250 mg of magnesium taurate a day.

I take 250 mg of Mg Taurate at night alone (just before sleep). In the morning usually another 125 mg.  As long as you space out the dose, your kidneys will take care of the rest.

It really is hard to overdose on Magnesium.

For comparison, Milk of Magnesia people take for stomach upset has 415 mg of Magnesium in a 5ml capfull.

Hi Kat,

ive been taking TKIs for 10 years now. About two months after starting in Gleevec, I started getting the bone pain/muscle cramps. My oncologist recommended taking a magnesium supplement, which would help with the pain. Over the years, I have increased my magnesium to about 500 mg. I started first with Slow Mag, and switched to the generic Mag 64 because of cost. I also take Doctors Best Magnesium Glycinate, which I also started my children on because as someone mentioned magnesium is low in our refined foods.

My mag level has been between 1.6-1.8 the last 10 years, with mostly at 1.6. I be learned to live with it, but I do get fatigued. In addition when I switched to Tasigna in 2010, I became hypothyroid, and have had difficulty in getting my thyroid adjusted which also depends on magnesium.

As I was searching for research on TKIs and magnesium, I found this site and joined. There are some articles on the web regarding the question you asked. Also monitor the normal range on your labs to see if you become low. There is a magnesium RBC lab for a more specific result. Unfortunately most insurance companies do not cover it.

i hoped I could be a help. Good luck and be involved in your care!

Angie

Thanks, Angie.  If I had the muscle/joint/bone pain or cramps, I would most certainly be on the magnesium supplement bandwagon by now.  I can only present the extreme muscle fatigue and weakness, and unmanageable and inexplicable weight gain.  Every time my PC checks my TSH it appears that I am inching out of normal range and into (wait for it) hyPERthyroid territory, and she prescribes me to take even less.  (I had a subtotal thyroidectomy in 1979 for benign adenomas.)  I joked with her the last time she lowered me:  Hey, why don't I just stop taking it altogether?  It doesn't appear that I even NEED a thyroid to produce the hormone.  It's all very strange, not what very many others report, and the picture is so murky that my various doctors just shrug.  I don't know whether to blame CML or TKIs.  But one thing I KNOW:  I'm inside a completely different body than I had before diagnosis, one that I don't recognize and one I can't control.  If my PC agrees, I may start looking at (first) magnesium supplements, and then all the other ones Scuba loves.  As Martin Luther King, Jr. said, "Hope is the final refusal to give up."  Your info was helpful!