Surprisingly, not all positive results from 5-panel drug tests indicate illicit drug use or substance abuse. (Learn more in Introduction to the 5-Panel Drug Test). A number of legitimately prescribed prescription drugs and over-the-counter (OTC) medications contain ingredients that can trigger false positives.

Both drug-induced impairment and false positives have serious consequences in the workplace. Because of this, employers and employees need to understand the issues surrounding the use of commonly prescribed and OTC drugs in the workplace.

Prescriptions and OTC medicines can generate false positives

The 5-panel drug test is the basic screen for drug use and abuse in the workplace. This test uncovers the presence of THC (cannabis), cocaine, opiates, amphetamines, and PCP in blood or urine. With the exception of PCP, all of these drugs can be legally prescribed to treat legitimate health conditions.

Most employers are aware that opiates and amphetamines can be prescribed to address legitimate injuries and health concerns. In these cases, the presence of opiates and amphetamines in their screen doesn’t automatically mean that the employee using them should be disciplined or dismissed. It may be possible to have employees continue working with reasonable accommodation that removes them from safety-sensitive duties while under a doctor’s care.

What’s less widely known is that some unexpected prescription and OTC medications can also trigger positive drug test results.

A few examples are listed below.

Prescription drugs that can show up in drug test results:

  • Bupropion (generic Wellbutrin) is an antidepressant that can generate a positive test result for amphetamine

  • Metformin (Glucophage) is commonly prescribed for type 2 diabetes but may test positive for amphetamine or methamphetamine

  • Ritalin (Methylphenidate), prescribed to treat ADHD, can show up as amphetamine, methamphetamine, or LSD

  • Zoloft (Sertraline), an antidepressant, has been known to test positive for benzodiazepines or LSD

OTC medications with problematic ingredients:

  • Robitussin and Delsym (Dextromethorphan) are cough syrups that can generate a positive screen for opiates and PCP

  • Benadryl, Tylenol PM, and Advil PM (Diphenhydramine) can test positive for methadone or PCP

  • Advil, Motrin, and Aleve (Ibuprofen and Naproxen) are common OTC anti-inflammatory pain meds that can show up as barbiturates, THC, or PCP

  • Sudafed (Pseudoephedrine), used for sinus and nasal congestion, can test positive for amphetamine or methamphetamine

These are just a few of the prescription and OTC drugs that can be problematic when present in the body while collecting a drug test sample. To be better informed, it’s best to always ask your doctor or pharmacist about the potential side effects, including effects on drug test results, whenever taking medication.

Prescription and OTC medicines can affect workplace safety

Many prescription and OTC medicines have side effects. Some of these side effects can disrupt worker performance and undermine workplace safety.

Prescription and OTC drug side effects to look out for include:

  • Shortened attention span

  • Disrupted concentration

  • Short term memory disruption

  • Slower reaction times

  • Loss of coordination

  • Loss of balance

  • Drowsiness

  • Agitation

Even without a positive drug test result, when an employee shows signs of any of these side effects, it’s important to intervene so that workplace safety is maintained. As you do this, be mindful of the requirements for reasonable suspicion and the worker privacy rights insured by the ADA.

Proactive steps employers can take

When it comes to preserving a drug-free workplace and preserving workplace safety, it’s best to be proactive rather than wait for an incident to occur. Two things employers can do are provide education to their employees and establish a strong and clear workplace drug policy.

Educate employees and managers

Members of your team need to be taught the potential dangers of impairment caused by prescription and OTC medicines in the workplace. While the dangers of illicit drug use and misuse have received a lot of publicity and may be top of mind, the dangers posed by prescription and OTC medication may not be so obvious. People need to understand both the potential dangers to workplace safety and risks to their employability that false positives and side effects pose.

Review and revise your drug-free and safe workplace policies

Make sure that all aspects of drug-free workplace and workplace safety policies are comprehensive and align with the current law. Consult an attorney familiar with labor law and Department of Transportation (DOT) regulations to help you do this.

Make sure policies are comprehensive, addressing fitness to work, reasonable accommodation, and worker privacy (as dictated under the ADA). Spell out how you, as the employer, will respond to potential false positives and impairment due to the use of prescription and OTC medication in the workplace. Be sure your employees and managers understand these policies and procedures.

Benefit from understanding and addressing prescription and OTC drugs in the workplace

Common prescription and OTC medicines can seem harmless. However, in the workplace, their use can cause impairment and/or result in positive drug test results. (Learn more in Prescription Drugs in the Workplace: Employer Rights vs. Employee Privacy Rights). This can have serious, long term consequences for both employers and employees.

By taking the time to understand and address the issues surrounding prescription and OTC medication, employers help insure workplace safety is maintained.