Expert: Dr.Paul Skett - 5/7/2008

Question
I am successfully living with chronic pain, college full-time with a 4.0 average, my writing is being published, I walk several miles every day. I take Methadone 30mg. 4x/day and have for years. At my last urine screen, my pain specialist said that my methadone level was low. I have not taken my meds any differently than I always do, my LFT's are perfect, there has been no change that I can identify of any kind. What could cause my urine to show decreased levels of Methadone (besides the obvious testing error)? And how common are testing errors anyway? I see my specialist once a month (next Wednesday) and would like to have some suggestion as to what could have precipitated the difference. Thank you.

Answer
Hi, Elizabeth,

First congratulations on living a full and active life despite what must be difficult pain management!!

I wouldn't worry too much about a temporary drop in methadone urine concentrations - it is the blood levels that give you the pain relief - I assume you have not noticed any decrease in pain relief.

The concentration of methadone in urine depends on the acidity of the urine and really has little to do with blood levels - it is just a more convenient way of making sure there is still methadone in your system.

Urine acidity can change significantly quite quickly - different foods etc.

If you detect a decrease in pain relief, however, then you should report this to your physician who will adjust the dosage.

Hope this sets your mind at rest and good luck!!

Paul