Someone I know tested positive for cocaine on drug test at work. What can cause a false positive?

My drug was not positive but it shows 11 in ng/mL

Hey fred5ner,

The following link lists substances that will cause a false postive for cocaine:

https://www.drugs.com/article/false-positive-drug-tests.html

Scroll down the list and yes you will see that quinine (in tonic water) can cause a false positive for cocaine. He can check his other medications against this list also. There are references included if he needs proof to give to the boss.

Best wishes,

Laurie

Tonic water is now known to be dangerous to the heart.

Drug tests nowadays are pretty specific. He should ask for a second test to confirm, as one of several things may have occurred:

He may have broken his nose, or recently had surgery or a procedure involving the nasopharynx... in which case, he may have actually been given cocaine and not realized it.

He may be on a pain med that contains cocaine (i.e., Brompton's Solution, a mixture of morphine and cocaine) and not realize it contains cocaine.

He may drink tea containing coca leaves, and have a non-false positive result.

The lab may have messed up the test... It does happen; they are human.

(It might be helpful to have a complete list of meds... including herbals)

Good luck!

-cooksii