Does Lidocaine Ointment Cause False Positive Test Results For Cocaine?

Posted on Thu, 27 Aug 2015

Medically reviewed by Ask A Doctor - 24x7 Medical Review Team

Thu, 27 Aug 2015 Answered on

Fri, 18 Sep 2015 Last reviewed on

Question : This question is complicated. If I am on dialysis waiting on a transplant and also on pain management for several different issues and they have prescribed lidocaine ointment for me as well as my pain medication. If I put the lidocaine ointment on a tooth for I was having a toothache on the day of my swab test which I inform them about would I test positive for cocaine? I am confused over this result

Answered by Dr. Dr.Albana Sejdini Greca (1 hour later)

Brief Answer:
No,lidocaine ointment won't cause false positive cocaine test...

Detailed Answer:
Hi,

I am sorry for the situation you are in.

Lidocaine ointment itself won't cause a false positive cocaine drug test.
Kidney problems, especially kidney infection can cause a false positive testing.
Furthermore, if you have been using antibiotics (like penicillins) recently, those can also cause false positive cocaine drug test.

Try to relax and do not see it as a problem. You can repeat the testing after a few days.

All the best! Let me know if you have further queries!
Dr.Albana

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar