I take 30 mg cinacalcet every other day. It is a very useful drug to bring the level of Parathyroid hormone (PTH), a very important hormone in the body whose chief function is to control the level of Calcium in the blood. I need to test the level of PTH in my blood regularly to figure out whether I need to modify any medication doses.
The trouble is I take cinacalcet every other day. So, it seems like the level of PTH might be going up and down depending on whether I have taken the drug or not. I am not sure of this. It just seems that way. There should be a few hours in the day after taking the drug when the level of the drug in the blood should be higher than otherwise. Which means the level of PTH should be lower during these few hours than otherwise. How do I figure out when I should be drawing my blood sample to ensure that I get a correct reading of my PTH level?
Similarly, I have recently started dialyzing with a high flux dialyzer every other day. I use a low flux dialyzer otherwise. High flux dialyzers give much better clearances and are also good at removing the so-called middle molecules which are known to cause severe problems in long term dialysis patients. Now, I draw my blood samples for regular tests every month. Should I draw the sample on the day I have dialyzed with the high flux or the low flux?!
Samples drawn after the high flux dialysis are bound to contain less toxins than those drawn after low flux dialysis!
I really have no clue about the answers to these questions.
If, on the other hand, I was taking cinacalcet every day or was dialyzing with the same dialyzer every day, there was no problem because every day is like any other day. Drawing blood on any day would give you the same result.