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Nilotinib and potassium

Hi all,

I was diagnosed with CML just over 2 months ago at the age of 57. I had a bone marrow biopsy to confirm it but the consultant was so sure of the diagnosis that she put me on Imatinib straight away (literally on the same day of my blood test). I had no problems with it, but after a week and after reading all the relevant papers I could find (I am a biologist and this was my way to come to terms with the news) I asked to switch to Nilotonib. My Sokal score was quite high 1.35 and the consultant agreed to the change.
The results have been quite impressive - I had a blood test today and WBC, RBC and platelets are all normal.. However, later in the afternoon the doctor called me worried about the high potassium level of my blood (6.4) and I was admitted urgently to the oncology ward. I had another blood test and an ECG and this time it was all normal so I was allowed home.
Has anybody had similar problems?. I have no other side effects from nilotinib and I feel really well. I know that high potassium levels can cause irregular heart beat. My resting heart beat is rather low, 50-52 and I occasionally have extra systole when it feels like my heart has skipped a beat. The ECG however are always normal with normal QT intervals
I was advised to carry on taking nilotinib but I need to be particularly aware of any changes to my heart rhythm

Thanks for any advice

Luisa

Hi Luisa, welcome to this forum and website. I hope you find it helps you with how you manage your therapy.

I agree that given your sokal score with your choice to change therapy with a 2nd generation TKI- the only other one that NICE has approved for 1st line (dasatinib is only available through the Cancer Drug Fund).
However, nilotinib does have a issue with QT intervals- as you have mentioned. However, given that your further tests proved normal it might be that the initial impact of nilotinib has and will continue to stabilise.

You might like to check your magnesium levels too. Low magnesium can also cause the symptom you describe as 'feels like my heart has skipped a beat'. Some months ago I was suffering from this quite badly- every night on lying down. It is quite distressing I must say. However, I restarted supplementing magnesium- I use a topical oil/cream which I find is easy to include in my daily routine. The symptoms of skipped heart beat lessened over the next couple of weeks and stopped altogether after around 3/4 weeks.

It might be worth a try.

If you look at earlier posts on magnesium on this forum you will find lots of links. If you can't then let me know and I will post them again.

Good luck with your therapy- hope you do not need to reconsider, but you might be able to access dasatinib through the CDF if you continue to have this side effect with nilotinib.

Best wishes,
Sandy

Hi Sandy,
Thanks for your reply. I found a bit strange (and a bit worrying)that Mg deficiency cannot be picked up in a blood test. There is a risk associated with nilotinib and low Mg and K levels but if the Mg levels cannot be accurately measured how do we know if one is at risk or not?
If I want to supplement my Mg intake wouldn't it be easier to take some multivitamins/minerals rather than using the oil?

On a different note and after reading some of the other posts regarding energy level, exercise, etc I wonder if I'm very lucky or a bit irresponsible. I refuse to have my life changed by CML and so I carry on doing exactly what I was doing before - I work full time, I do yoga, play badminton, swim, walk, etc I did not feel ill before the diagnosis (I walked 12 miles in the Yorkshire Dales the day before finding out that my WBC was 277,HGB 88, platelets 650!) and I don't feel ill now. Perhaps I'm still in denial.....I hope not

Best wishes

Luisa

I Luisa,

You might like to take a look at the following link- one of many resources about Magnesium deficiency etc. but an 'easy' read.

I prefer to use the transdermal method of supplementing with this.. I take a lot of Vits/minerals etc. so another tablet would be one too many for me.... and also magnesium is not easily absorbed in the gut.

http://drsircus.com/medicine/magnesium/magnesium-deficiency-symptoms-dia...

I am glad your energy levels are good ;o) yes maybe you are lucky- I am sure you are not irresponsible! Keep on doing what your doing.

Best wishes,
Sandy

Not so sure about all that blurb about Mg, being almost the cause of every known disease, etc. It sounds to me like a ploy to get people to buy whatever Mg supplement he sells. Sodium bicarbonate(baking soda) to treat cancer, heart disease, etc? - complete and utter rubbish!
A good diet with plenty of green vegetables, seeds, nuts and some chocolate is a much better way to get enough Mg.
Please let's have information based on serious science and not on unfounded statements

Luisa, it is entirely up to the individual to accept or reject information such as that on sites such as Dr. Sircus and others. There are plenty of links on this and other sites that are based on 'serious science', although I would argue that you will never have total consensus between either doctors or scientists.

I do not agree that all information that is outside the mainstream is 'utter rubbish' and I would point out that only a decade or so ago many researchers involved in the area of CML totally rejected Brian Druker's early research that by targeting the protein kinases would be either safe or effective in treating CML.

I do not know of any 'serious scientific' published research that 'proves' that eating green vegetables, seeds, nuts and chocolate will give you enough magnesium for optimal health. But I too am capable of making an informed choice about how I maintain my own health and will continue to provide links to both mainstream medical research as well as CAM.

I appreciate that you might not agree and wish you well in any way you wish to continue to support your own health. I expect the same from you.

Best wishes,
Sandy

Hi Sandy,
Fair enough comment on your part - apologies - no offence intended. I still think Dr Sircus's website is very misleading but from now on I'll keep my opinions to myself.

Regards

Luisa