Employers today commonly require new employees to submit to and pass a drug test before starting work. However, certain medications such as those used to treat chronic pain, can result in a failed drug test because they are opiates or narcotics. If you fail a drug test because you had medications in your system for which you have a prescription, a company typically can’t rescind a job offer, but exceptions exist.

Purpose of Drug Testing

The purpose of employee drug testing is usually to ensure that workers are not drug addicts. It’s a way for companies to protect themselves from employees who may come to work stoned and steal from the company to feed their addictions. While a wide variety of medications that would show up on an employment drug test can be used to obtain a high, people with certain medical conditions obtain them legally and need them to function.

What to Do

If you test positive for a drug approved by the United States Food and Drug Administration and you have a doctor’s prescription for it, you can provide a copy of the prescription, or a note from your doctor, to the company as proof that you’re not using drugs illegally. A better approach, however, would be to let the agency conducting the drug test know before the screening of any medications you use that might show up on the test. That way you don’t have to explain later to the employer why you tested positive.

When Offers Can Be Rescinded

Even when you have a doctor’s prescription for a medication that shows up on a drug test, an employer can sometimes legally rescind a job offer. For instance, if you take oxycodone for severe, chronic pain and you received a job offer, the employer may be within its right in rescinding the offer if the position was airline pilot. That’s because it’s not recommended that heavy machinery be operated while on the medication. It can produce foggy thinking and impaired reaction time, and those side effects can put passengers in danger. Additionally, an employer is not under obligation to hire someone who uses medical marijuana with a doctor’s prescription, because although some states allow the drug’s use medicinally, it is not approved by the U.S. Food and Drug Administration to treat any condition and is prohibited by the Controlled Substances Act.

When Offers Must Stand

If you can provide proof that you have a prescription for a medication and the medication does not hinder your ability to perform the job you were hired, the employment offer must stand. The Americans with Disabilities Act makes it illegal for companies to discriminate on the basis of a disability, and rescinding an offer because a person uses a medication needed to treat a medical condition constitutes disability discrimination.