What Drugs Will Disqualify Drivers from Operating Commercial Vehicles?

The connection between DOT drug tests and prescription drugs can be a muddy one, especially with the upcoming Clearinghouse-II.

Many CDL drivers take prescriptions on a regular basis to treat ailments or help with diagnosed medical conditions. However, due to strict DOT drug testing requirements, many wonder whether a particular drug will cause them to fail a drug test and disqualify them from getting behind the wheel. This is an especially concerning situation since the FMCSA Drug and Alcohol Clearinghouse-II will soon revoke the CDL/CPL privileges of drivers with "prohibited" statuses in the Clearinghouse database.

Plain and simple, there are drugs (both legal and illegal) that commercial drivers are prohibited from taking according to federal regulations. But in other cases, the answer isn't as clear, and it depends on the opinion of both the prescribing doctor and the DOT medical examiner.

To find out which prescription drugs CDL drivers are allowed to take, we need to take a closer look at which drugs they're tested for. 

The DOT Drug Test Panel

Drivers who are required to be enrolled in a DOT drug and alcohol testing program will be tested during the pre-employment process, and then periodically afterward, for the following substances:

• Marijuana 
• Cocaine 
• Amphetamines (Amphetamine, Methamphetamine, MDMA, MDA) 
• Opioids (Codeine, Morphine, Heroin, Hydrocodone, Hydromorphone, Oxycodone, Oxymorphone) 
• Phencyclidine (PCP)

It probably goes without saying that a positive truck driver drug test result for any illegal substances included on the DOT drug test panel – or a prescription medication that wasn’t prescribed by a medical doctor – will result in a violation of DOT drug testing regulations and must be reported to the DOT Clearinghouse.

Even though the drugs on the Opioid panel are legal when used under the care of a physician, they are considered disqualifying by the DOT because of their ability to impair reaction time and focus.

Even with a prescription, a driver's drug results will likely be marked “Negative with Safety Concern” by a Medical Review Officer (MRO), who will defer them to their employer (and likely their prescribing physician) regarding their ability to drive safely.

Drug Use & DOT Physical Exams

A driver's drug use will inevitably come up during the DOT physical exam process, which occurs at least every two years for most drivers. At the beginning of the examination, the driver will be required to disclose all the medications and supplements they take, whether or not they’ve been prescribed by a doctor.

One thing to keep in mind during this process is the DOT disqualifying drugs list which prohibits the use of any narcotic, amphetamine, or habit-forming drug by a CMV driver unless the prescribing physician clears the driver for duty and writes a letter to the medical examiner that gives the driver clearance to drive.

It’s important to note that the medical examiner's professional opinion can still declare the driver unfit to drive based on their medication usage, even if the prescribing doctor's letter says the opposite.

What Drugs are Prohibited by the DOT?

According to the DOT, any driver that takes a controlled substance that is included in 21 CFR 1308.11 (391.42(b)(12)), or other habit-forming drug, is medically unqualified to drive.

Some of the most commonly known medications on the list are:

• Amphetamine
• Codeine
• Fentanyl
• Hydrocodone
• Methadone
• Morphine
• Marijuana

The entire DOT medication restrictions list can be found here.

What if I have a prescription for a DOT-prohibited medication?

If any of your drivers take any medications included on the list of disqualifying medications for CDL drivers, they will need a letter from their doctor that clears them to drive before their next DOT physical exam.

If their doctor cannot provide the letter, they may need to reconsider their pain management or medical condition treatment plan to include non-opioid medications, so they can legally and safely drive on behalf of your company and won't need to worry about their DOT drug test and prescription drugs.

DOT Approved Medication List 2024

In most situations, medications are approved by prescribing doctors and Medical Examiners on a case-by-case basis. The FMCSA has also made some recent changes to previously disqualifying medications. 

• Anti-depressants
• Smoking-cessations, such as varenicline (Chantix)
• Muscle relaxer cyclobenzaprine (Flexeril), depending on the driver's side effects
• Short-acting anxiolytics (anxiety relievers), such as Lunesta and Ambien, dependent on the timing of the driver's use