By George F. Indest III, J.D., M.P.A., LL.M., Board Certified by The Florida Bar in Health Law
In representing nurses and other licensed health professionals, we constantly discuss positive drug screenings, usually from employer-ordered drug testing, with our clients.  These clients include nurses, pharmacists, dental professionals, mental health counselors, therapists, etc.  Often these individuals need to remember that if they apply for a job with a new employer or are working for a large corporation or the government, they are subject to employer-ordered drug screenings.  Most problems arise when the professional has applied to a hospital or a placement agency for work in a hospital and they must submit to a pre-employment drug test.
The client often contends that the result is a false positive and that some other substance must be responsible for it.

A positive result for any drug for which you do not have a valid prescription from a physician, including marijuana, will cause you to be eliminated from consideration for a new job or terminated from a current position and a complaint against your professional license, which could cause you to lose it.  We are routinely called on to defend such situations.

Series of Blogs to Discuss Substances that Can Mimic Prohibited Drugs on Drug Tests.

In the years I have been doing this, I have encountered many cases in which other substances have caused a positive result for a prohibited substance on a drug screening test.

In this series of blogs, I intend to discuss some of the substances scientifically shown to cause false positives on employer-ordered drug screening tests.  This is the first in the series.

Over-the-Counter Medications Mimicking Amphetamines on Drug Tests.

Following is a discussion of substances that can cause a false positive for amphetamines on a urinalysis drug test.  This material comes from an article in Case Reports in Psychiatry published in 2013. (Ref. 1)
Many prescription pharmaceuticals and over-the-counter (OTC) medications have been previously reported in the literature to cause a false-positive result for amphetamines on urine drug screens. Many OTC medications have been reported in scientific literature to produce false positives for amphetamines on urine drug screenings, chiefly antihistamines.

The OTC medications that have been documented to and are well known as causing false positives for amphetamines on drug tests include nasal decongestants, Vicks inhaler, MDMA (3,4-Methylenedioxy methamphetamine;  commonly known as ecstacy, molly, mandy or X), and pseudoephedrine.  (Refs. 1-5)  Some of these are prohibited medications that cannot be prescribed and are only available as “street drugs” such as MDMA.

Prescription Medications Documented as Mimicking Amphetamines.

Prescription medications known to have mimicked amphetamines on testing include antipsychotics and antidepressants.  (Refs. 1 & 2)
The prescription medications known to cause false-positive amphetamine urine drug screen include fluoxetine, selegiline, ranitidine, trazodone, nefazodone, brompheniramine, phenylpropanolamine, chlorpromazine, promethazine, ephedrine, methamphetamine, and labetalol.  (Refs. 2-5)  However, the fact that the individual taking the drug test might have a prescription for one of these might cause the employer to disqualify the employee or potential employee from consideration for the job.
Bupropion (an atypical antidepressant that inhibits norepinephrine and dopamine re-uptake), is a drug used to treat depression and smoking cessation, but may also be used off-label to treat ADHD.  It has also been documented as causing false positive results for amphetamines on drug screenings.  (Ref. 6)
The drug atomoxetine has metabolites that are similar to those of amphetamines (phenylpropan-1-amine verses phenyl-propan-2-amine).  This could also result in a false positive on a urine drug screen.  (Ref. 1)


Other Discussions in Future Blogs.

In future blogs, I intend to discuss false positive claims associated with use of ibuprofen, amoxicillin, coca leaf tea, poppy seeds and other common substances and medications.  Stay tuned.

Contact Experienced Health Law Attorneys in Matters Involving PRN or IPN.

The Health Law Firm’s attorneys routinely represent physicians, dentists, nurses and other health professionals in matters involving PRN or IPN. Our attorneys also represent health providers in Department of Health investigations, before professional boards, in licensing matters, and in administrative hearings.

To contact The Health Law Firm, please call our office at (407) 331-6620 or toll-free at (888) 331-6620 and visit our website at


1. Fenderson JL, Stratton AN, Domingo JS, Matthews GO, Tan CD. Amphetamine positive urine toxicology screen secondary to atomoxetine. Case Rep Psychiatry. 2013;2013:381261. doi: 10.1155/2013/381261. Epub 2013 Jan 30. PMID: 23424703; PMCID: PMC3570929.
(Accessed on May 20, 2023.)
2. Brahm NC, Yeager LL, Fox MD, Farmer KC, Palmer TA. Commonly prescribed medications and potential false-positive urine drug screens. Am J Health Syst Pharm. 2010 Aug 15;67(16):1344-50. doi: 10.2146/ajhp090477. PMID: 20689123.
3. Vincent EC, Zebelman A, Goodwin C, Stephens MM. Clinical inquiries. What common substances can cause false positives on urine screens for drugs of abuse? J Fam Pract. 2006 Oct;55(10):893-4, 897. PMID: 17014756.
4. Rapuri SB, Ramaswamy S, Madaan V, Rasimas JJ, Krahn LE. ‘Weed’ out false-positive urine drug screens. Current Psychiatry. 2006;5(8):107–110. [Google Scholar]
5. Moeller KE, Lee KC, Kissack JC. Urine drug screening: practical guide for clinicians. Mayo Clin Proc. 2008 Jan;83(1):66-76. doi: 10.4065/83.1.66. Erratum in: Mayo Clin Proc. 2008 Jul;83(7):851. PMID: 18174009.
6. Reidy L, Walls HC, Steele BW. Crossreactivity of bupropion metabolite with enzyme-linked immunosorbent assays designed to detect amphetamine in urine. Ther Drug Monit. 2011 Jun;33(3):366-8. doi: 10.1097/FTD.0b013e3182126d08. PMID: 21436763.


About the Author: George F. Indest III, J.D., M.P.A., LL.M., is Board Certified by The Florida Bar in Health Law.  He is the President and Managing Partner of The Health Law Firm, which has a national practice.  Its main office is in the Orlando, Florida, area.  The Health Law Firm, 1101 Douglas Ave. Suite 1000, Altamonte Springs, FL 32714, Phone:  (407) 331-6620 Toll-Free: (888) 331-6620.

Current Open Positions with The Health Law Firm.  The Health Law Firm always seeks qualified individuals interested in health law.  Its main office is in the Orlando, Florida, area.  If you are a current member of The Florida Bar or a qualified professional who is interested, please forward a cover letter and resume to: [email protected] or fax them to (407) 331-3030.

“The Health Law Firm” is a registered fictitious business name of and a registered service mark of The Health Law Firm, P.A., a Florida professional service corporation, since 1999.
Copyright © 2023 The Health Law Firm. All rights reserved.