Creatinine levels in drug screens

Our company does pre-employment and random drug screening for DOT qualified employees as well as non-DOT employees.

The drug screen results notice that we receive from the lab states a number to represent the urine creatinine level. It says that cutoff/expected values are 20.0 - 300.0 mg%. I am amazed at how many we receive that are 'low' or 'high' with levels such as 12.2 or 351.1. (I received 4 today!) Our policy does not address the creatinine levels. I see that DOT says we have the option of requesting a retest, but that's about all it says about this issue.

Do any other companys address this, or is it basically ignored and the only result that counts is negative or positive?


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  • This happens to us all of the time. Our drug testing place says that it could be due to people taking muscle builders / drinking shakes or not drinking enough water. Also, they have stated it may indicate diabetes. So, if the ONLY thing on the drug test results is +/- on the creatine, we just ignore it. However, if the drug test shows dilution or a possibility of adulterants (i.e. nitrates or chromates) then we have an immediate retest.
    We have found it helpful to call people the day before the drug screen (we only give 24 hrs notice if its for a pre hire) and give them some guidelines (i.e. do not drink excessive amounts of water or eat a couple of pounds of poppy seeds, etc.).
  • Lorrie,

    In conjunction with the creatinine level, look at the "specific gravity." The person may be a health nut and simply have low toxicity. The specific gravity will be different if the person bought a gallon of herbal tea (as an adulterant that can be bought at GNC for the very purpose of passing a drug test.)

    The lab that conducts the testing should be able to advise you more clearly on the results.

    Here, a "dilute" sample is considered an unsatisfactory result and the offer is withdrawn.

  • Thanks for the information. I went back and looked at the 5 results I just received. One was normal, two were high creatinine, and two were low creatinine. Of the two low: one did not mention specific gravity but I was surprised to see that one did, and next to that it says *dilute specimen*, which I had not even noticed. I guess I expected it to be highlighted or somehow more obvious.

    Boy am I learning!

    You mentioned that you withdraw an offer when you receive a dilute specimen, what about if it is a random? Do you pay for a retake, or I have heard some say they offer a retake at the employee's expense.

    Thanks again for everyone's information. This forum is so helpful!
  • In some states, you are allowed to regard a diluted or adulterated specimen as a "fail". I believe DOT allows you to do this with an adulterated specimen, but I'm not sure on diluted.
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