DUIs and Narcotics: What You Need to Know

Why drug-related DUIs are more common—and more complex—than most people think

When most people think of a DUI, they imagine someone being pulled over for drunk driving after a night at the bar. But in some situations, that’s only part of the picture. In Montana, and in many other states, a DUI can also involve narcotics—including both illegal drugs and legally prescribed medications.

That’s right: you can be charged with a DUI even if you haven’t had a single drop of alcohol.

What Is a DUI Involving Narcotics?

In Montana, it is illegal to drive under the influence of any substance that impairs your ability to operate a vehicle safely. That includes:

• Illegal drugs like methamphetamine, cocaine, or heroin
• Marijuana (yes, even if it's legally purchased)
• Prescription medications like Oxycodone, Adderall, Ambien, or Xanax
• Over-the-counter drugs that cause drowsiness or dizziness

Unlike alcohol DUIs—which are measured by your blood alcohol concentration (BAC)—there is no clear threshold or legal limit when it comes to drugs. This makes narcotics-related DUIs more subjective, and often, more difficult to prove or defend against.

How Do Officers Test for Drug Impairment?

Without a breathalyzer equivalent for narcotics, law enforcement officers rely on a combination of techniques:

• Observation: Slurred speech, bloodshot eyes, slow reaction times, or the smell of marijuana.
• Field Sobriety Tests: Walking in a straight line, standing on one leg, following a light with your eyes—these physical tests help officers gauge coordination and mental focus.
• Drug Recognition Experts (DREs): Some departments have specially trained officers who conduct detailed assessments to determine what type of drug may be in a person’s system.
• Blood or Urine Tests: These tests can detect the presence of narcotics in your body, though they don't always indicate when the drug was taken or how impaired you were while driving.

Common Misconceptions

One of the biggest misunderstandings we see at Ryan, Miller & Coburn is this:
“If I have a prescription, I’m safe.”

Unfortunately, that’s not true. Even legally prescribed medications can impair your driving, and if law enforcement believes you were unsafe behind the wheel, you can still be arrested and charged with DUI. Many prescription drugs have warning labels about operating heavy machinery for a reason—because they affect your ability to react quickly and think clearly.

Another misconception:
“It’s just marijuana—it’s legal now.”

While recreational marijuana is legal in Montana, driving under the influence of marijuana is not. Just like alcohol, you can enjoy it at home—but if you drive while impaired, you're putting yourself (and others) at risk, and you could face criminal charges.

What Are the Penalties?

Montana takes DUI charges seriously, and that includes drug-related DUIs. The consequences may include:

• Jail time (especially for repeat offenses)
• Fines
• License suspension or revocation
• Required drug education or treatment
• Community service
• Probation
• Ignition interlock devices (sometimes, even for drug DUIs)

If the DUI results in an accident, injury, or involves a minor in the vehicle, the penalties can increase significantly.

What Should You Do If You’re Charged?

If you’ve been charged with a narcotics-related DUI, the first step is simple: don’t panic—and don’t go it alone. These cases are complex, and a strong legal defense can make a big difference.

At Ryan, Miller & Coburn, we examine every angle of your case:

• Was the traffic stop legal?
• Were proper procedures followed during testing?
• Were your rights violated at any point?
• Is there enough evidence to support the charge?

We’ll look for inconsistencies, errors in the investigation, and any opportunity to challenge the prosecution’s case. Our goal is to protect your rights and help you move forward with the best possible outcome.

Driving under the influence of narcotics is a serious charge—but it’s also often misunderstood. Whether you’re dealing with prescription medication or facing charges related to marijuana or other substances, knowing your rights is the first step to protecting your future.

You don’t have to face this alone—and you don’t have to guess your way through the legal system. Let us guide you through it.

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