Can You Get a DUI for Driving on Legal Drugs?

Most often, when we think about DUI charges, we think of driving while under the influence of alcohol or illegal substances. But, can you also be charged with a DUI for driving while on legally prescribed drugs?

While there are variations in each state’s laws, the answer is generally “yes” – you can get charged with driving while intoxicated for operating a vehicle while on prescription drugs. This is because states make a distinction between two types of DUI charges: “per se” and “impairment.” We will explain both below. The content of this article is for informational purposes only. It is not intended to give legal advice.

Per Se and Impairment Charges

In order to receive a DUI charge, the driver must be both:

  • Operating or driving a vehicle
  • Intoxicated or under the influence

These requirements lead to two different types of DUI charges: per se and impairment. It’s important to know the difference between both charges to understand why some medications, despite being legally prescribed to you, can be the cause of a DUI charge.

Per Se DUI Charge

A per se DUI is based upon the concentration of a substance in the driver’s blood. Typically, this will mean a driver’s blood alcohol count (or BAC). For example, in every state it is illegal to operate a vehicle with a BAC of .08% or higher.

Additionally, some states have established blood concentration limits for other substances – usually substances like marijuana, cocaine, and methamphetamine.

If a driver’s BAC or other substance concentration is over the state’s legal limit – whether they are visibly impaired or not – they will receive a DUI charge. It is important to note that, for per se DUIs, there is no need to prove impairment so long as the driver is over a legally established limit.

However, what happens when a driver is impaired by a drug but the substance is a legal substance? This is when an impairment charge is applicable.

Impairment DUI Charge

It is illegal to operate a vehicle while intoxicated or under the influence. According to every state’s laws, “under the influence” applies to more than alcohol or illegal drugs; it is also applicable to any substance that can cause impairment in a driver, including prescribed or over-the-counter medications.

In other words, if a police officer has reason to believe a person is driving while in an impaired mental or physical state, they can perform a substance test or even a field sobriety test. Poor performance during a field sobriety test is often used as evidence of driver impairment.

In cases where a driver’s substance tests come back clean, but they are still clearly impaired, the driver can still be charged with a DUI.

What Is Impairment?

There are many substances which can cause impairment in an individual, including prescription drugs.

The National Highway Traffic Safety Administration (NHTSA) defines impairment as any state under which an individual drives differently and less safely than they normally would. The NHTSA also states that even over-the-counter medicines can cause impairment and therefore result in a DUI charge.

Common signs of impairment to be mindful of include:

  • Extreme levels of drowsiness
  • Dizziness
  • Decreased hand-eye coordination and reaction time

If you are unsure whether or not you are impaired by a medication, the NHTSA cautions drivers: “if you feel different, you drive different.”

It is important to always be aware of warning labels on medication that advise the user to not operate heavy machinery or vehicles. Doing so can help prevent a DUI and, most importantly, keep you and others safe.

How Is Impairment Measured and Proven?

Since an impairment DUI does not solely rely on any form of blood concentration testing, the criteria for proving impairment typically consists of a field sobriety test or other tell-tale signs of intoxication, including:

  • Erratic driving
  • Unusual behavior
  • Slurred or noticeably slow speech
  • Red, glazed, or droopy eyes
  • Inability to focus or recall details

Some of the above items are also part of traditional field sobriety testing.

It is important to note that every state has impairment DUIs; however, states vary in the level of impairment for a DUI charge. In some states, a driver must only be proven to be intoxicated to the “slightest degree,” while in other states, a driver must be impaired to an “appreciable degree” in order to receive a DUI conviction.

Regardless of the degree to which a driver must be impaired, one thing is universally true: all states consider impairment, whether caused by an illegal or legal substance, to be a driving under the influence.

Prescription Drugs and Substance Abuse

Many people need to take prescriptions for a medical condition. However, prescription drugs can be abused. There are some noticeable signs of prescription drug abuse; a DUI charge is one of them. If you or a loved one has had one or more convictions for driving under the influence of drugs, it’s possible that a substance use disorder is the underlying cause.

If you suspect that you or a loved one has a problem with drugs or alcohol, contact a treatment center to learn how treatment can help prevent high-risk behaviors, such as driving under the influence.