HealthCareMagic is now Ask A Doctor - 24x7 | https://www.askadoctor24x7.com

question-icon

What Causes False Positive For On A Drug Screen For Marijuana?

default
Posted on Mon, 7 Jul 2014
Question: I recently tested positive for thc on a drug screen. I have not smoked marijuana since 1986, Two days after the MRO notified me of results, I discovered that my wife had given me two of her phenegran pills when I was nauseaus. I did not know what she gave me was a prescription drug. How can I reslove this?
doctor
Answered by Dr. Jonas Sundarakumar (1 hour later)
Brief Answer:
Request for hair follicle test

Detailed Answer:
Hello and welcome to Healthcare Magic. Thanks for your query.

Promethazine (Phenergan) is known to cause false positives on a drug screen for Marijuana. In your situation, I would advise you to inform the MRO about your recent intake of Phenergan pills. You can request him to do a hair follicle testing which would be more specific for detecing Marijuana. A negative hair follicle test would be sufficient to prove that the urine drug screen was only a false positive.

Wish you all the best.

Regards,
Dr. Jonas Sundarakumar MBBS., DPM., MRCPsych.(U.K.)
Consultant Psychiatrist
Note: For more detailed guidance, please consult an Internal Medicine Specialist, with your latest reports. Click here..

Above answer was peer-reviewed by : Dr. Prasad
doctor
Answered by
Dr.
Dr. Jonas Sundarakumar

Psychiatrist

Practicing since :2003

Answered : 2190 Questions

premium_optimized

The User accepted the expert's answer

Share on

Get personalised answers from verified doctor in minutes across 80+ specialties

159 Doctors Online

By proceeding, I accept the Terms and Conditions

HCM Blog Instant Access to Doctors
HCM Blog Questions Answered
HCM Blog Satisfaction
What Causes False Positive For On A Drug Screen For Marijuana?

Brief Answer: Request for hair follicle test Detailed Answer: Hello and welcome to Healthcare Magic. Thanks for your query. Promethazine (Phenergan) is known to cause false positives on a drug screen for Marijuana. In your situation, I would advise you to inform the MRO about your recent intake of Phenergan pills. You can request him to do a hair follicle testing which would be more specific for detecing Marijuana. A negative hair follicle test would be sufficient to prove that the urine drug screen was only a false positive. Wish you all the best. Regards, Dr. Jonas Sundarakumar MBBS., DPM., MRCPsych.(U.K.) Consultant Psychiatrist