Tested positive for Phenobarbital without taking it--what happened?

[kermit]

PLEASE HELP!

I tested positive for Phenobarbital during a urine drug screen (GC MS). I take Fioricet and Fiorinal (and have prescriptions). I have never experimented with drugs, take only what is give to me by my doctor, and have 3 years of "clean" tests from my health care provider (she only provides prescriptions with a clean urine test). I am such a boring person--no drinking, smoking, or illicit drugs. I am DESPERATE to find out if high doses of barbiturates can be mistaken during the GC MS process as Phenobarbital. The "positive" result is > 300, and I tested 310.

I am petite, 5'1" and weigh less than 100 pounds, although I doubt that it is a factor. I also have a pseudocholinesterase deficiency, again probably not a factor.

Since this issue, the company rescinded the job offer and I am unable to reapply for another job for at least 1 year. So, I am unemployed, cannot afford an attorney, and am 100% certain that I did NOT take phenobarbital.

PLEASE PLEASE if you can help, I would be very grateful.

THANK YOU!!!

[tinmuning]

Both Fioricet and Fiorinal can cause false positives on drug tests. If you're still on prescription for both drugs when the test was taken, you can show them the prescription. Ideally, the prescriptions should be shown before the test.

A false positive can occur with any test and questionable results should be repeated. As said in other drug test forums, a false positive result to phenobarbital is one of the most common occurrence.

[kermit]

THANKS for your post. With all that is out there about this being an error, I still lost the job and will be unable to reapply with the corporation for ONE YEAR. With all of the technology available, it would be very helpful if the medical review officers would do more to research questionable results when the "patient" has legitimate prescriptions and known errors exist. I am working on getting my name cleared so that I can reapply sooner. When the apology comes from the national lab comes I will post.