What Causes False Positive Result For Amphetamines On Drug Test After Taking Methyldopa?

Posted on Thu, 3 Sep 2015

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

Thu, 3 Sep 2015 Answered on

Thu, 24 Sep 2015 Last reviewed on

Question : I am 9 weeks pregnant and I have never taken drugs in my life. I tested positive for amphetamines on a drug test last week. The midwives clinic I am attending is threatening to call social services. All I take is Methyldopa, over-the-counter prenatal vitamins, over-the-counter folic acid, and over-the-counter cetirizine (generic for Zyrtec). Can either of these test positive for amphetamines and what should I do? I will not allow anyone to take my baby for something I have not done.

Answered by Dr. Aarti Abraham (3 hours later)

Brief Answer:
Methyl dopa can test positive.

Detailed Answer:
Hello
Thanks for writing to us with your health concern.
Methyl dopa at times is reported to cause a false positive test for amphetamines.
In all probability, you might have had a screening urine test.
Any reliable laboratory will easily differentiate between the two, so please insist on having that done,
All the best,
Please feel free to discuss further.

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