You are here

Low drug concentration (nilotinib)

Categories:

Hello again,

testing time has just passed so I'm back for more info. My wife has recently had some less than ideal results. Here are PCR rest results for background:

9 months after dx: PCRU
12 months: 0.0074
15 months: o.oo73
18 months (most recent) 0.011

She has been taking nilotinib since diagnosis at 600mg daily, and has never missed a dose. For her most recent tests, the doctor also ordered a drug concentration test. The result was 406 ng/ml, which from what I understand is quite low. I should note that the blood was drawn in the morning 12 hours after her last dose, and that this was the first time she had done a blood draw before taking her medicine in the morning. Also at the time of her last test, her liver enzymes were elevated and her platelets were lower than the normal range, but each were normal in this latest test.

I was hoping that some of you might be able to shed some light on this situation. What factors could contribute to low concentration? Is the blip up cause for concern? And does the time of blood draw in relation to the time that medication is taken affect PCR results to a significant degree?

I would be very grateful for your thoughts and advice. Thanks!

Chris

Hi Chris

Id say firstly your wife is practically MMR4 (only out by a smidge) still. Some of us have taken decades to get to that level so that’s the 1st positive.

Secondly anything below MMR4 which your wife practically is (a tiny bit above) is indistinguishable to PCRU. She is still in an extremely safe area and has very very very low CML.

I don’t believe the dose on the day of a PCR test would make any difference personally. Absorbing the meds can fluctuate and I believe diet can have an impact has any of that changed recently for her? I find I get better results the crappier I eat ie lots of fattier foods. I realise on Nilotinib we have the fasting so not sure how that plays a part but it seems to ring true for me at least.

I wouldn’t worry at all about a single test. If another test shows a 0.5 log increase then it could be a mutation but you won’t know for sure until mutation analysis is performed. There are many reasons for rises and very rarely is that due to one of those so I would relax for now.

Another thought is she on any other medication that she wasn’t on before too? And was the PCR performed at the same lab as usual?

Al

Hi Chris,

"...For her most recent tests, the doctor also ordered a drug concentration test. The result was 406 ng/ml, which from what I understand is quite low. I should note that the blood was drawn in the morning 12 hours after her last dose, and that this was the first time she had done a blood draw before taking her medicine in the morning."

I think the fact that she had not taken her drug before the drug concentration test may well be relevant - but I am not expert in this so my logic may well be questionable - but as this was not a PCR test but rather a drug level concentration test so, to me, this result shows the 'trough' (lowest) level? 

Sandy