Are your medicines getting washed out during your dialysis session?

I have been suffering from sinusitis for the past month or so. I was prescribed antibiotics but to no avail. I was then referred to a pulmonologist who advised a CT scan of the Paranasal Sinuses and simultaneously put me on two potent antibiotics along with an anti-allergic medicine. I started taking all these medicines in the hope that the sinusitis would resolve.

One thing I have learnt in the past is that dialysis can remove some drugs rendering them useless. Whenever I am prescribed a new drug, I make it a point to refer to a guide such as this one or this one. These guides have a lot of very useful information about the drugs that get dialysed out during a dialysis session including information for Low Flux Hemodialysis, High Flux Hemodialysis and Peritoneal Dialysis.

So what do you do if a drug that has been prescribed can get dialysed out?

It all depends on when you are supposed to take the drug and when your dialysis session is. For example, if you have to take the drug after breakfast and you have your dialysis session in the morning, you should check with your doctor if you can take the drug after your morning session? Things can get tricky if your session is in the afternoon and you have to take the drug in the morning. What do you do then? What if you have to take the same drug in the evening? If your morning dose is going to get washed out during your dialysis session, then you will be getting only about 50% of the dose every other day (assuming you are getting thrice weekly dialysis).

One more option that is explored at times is to increase the dosage of the drug to account for the removal of the drug during dialysis. This is done assuming that the drug is removed only partially. However, this can be quite complicated as you would need to know how easily the drug is dialysed out and this information is rarely available.

All this can lead to serious problems.

While there are no easy answers, it is important that we be aware that the drugs we take can be removed during the dialysis session. Remember, there are thousands of drugs that doctors can prescribe to different patients and it is impossible for them to remember which drugs get dialysed out and which do not. It is up to us, the patients, to read up on this and have a meaningful discussion with our doctors. More often that not, doctors can come up with solutions for this on the lines above.

One important consequence of this is with Blood Pressure medications. Some patients report their Blood Pressure rising after a couple of hours of dialysis. One possible suspect in this case is that the Blood Pressure medications they are on could be getting dialysed out during dialysis. It could be worth exploring switching to a drug that does not get removed or tailoring the dose.

I realised when I referred to the files I linked to above that one of the antibiotics and the anti-allergic were removed during dialysis. I called my nephrologist and asked him what to do. He advised to change the time I take those medicines so that they get enough number of hours in the body and thus, an opportunity to act.

I am glad I did this because otherwise, I would not be getting the adequate dose of those drugs and my problem would take longer to resolve or may not resolve at all.