Non-Alcohol-Related DUI

Generally, driving under the influence (DUI) is associated with alcohol; however, other substances—such as illicit drugs and prescription medication—can impair a person's driving ability, and driving while using these drugs isn't at all uncommon.

So, how do states handle driving while impaired (DWI) cases when it comes to illicit drugs or even prescription medicines?

Drugs & Impaired Driving

For purposes of this topic, we can categorize the drugs most commonly involved with impaired driving as illicit drugs, prescription medication, and the ever-controversial marijuana.

Illicit Drugs

When something is “illicit," it is illegal.

Common examples of illegal drugs include:

  • Cocaine.
  • Heroin.
  • LSD (“acid").
  • Methamphetamine.
  • MDMA (“ecstasy" or “molly").

These drugs impair your senses in numerous ways, varying from hallucination and delusion to nausea and tremors.

Prescription Medication

Prescription medicines that commonly impair driving include antidepressant medication, anti-anxiety medication, sleeping medication, pain medication, and even prescription-grade medications for allergies or common cold symptoms.

Just like illegal drugs, prescription drugs can cause a number of side effects that impair driving, such as:

  • Sleepiness.
  • Blurred vision.
  • Dizziness or fainting.
  • Delayed reaction times.
  • Problems focusing.
  • Nausea.
  • Tremors.

Understand that while prescription medicine is legal for the patient for whom it is prescribed, it becomes illegal when someone else abuses it.

Over-the-Counter Medication

For some ailments, such as allergies, the flu, or a cold, people opt for over-the-counter (OTC) medications. OTC medications can cause some of the same side effects as prescription medicines; therefore, they also can impair your driving.


If you're wondering whether it's legal for you to use marijuana, you're not alone.

Currently, marijuana is illegal on a federal level; however, some states have passed their own laws related to the growth, possession, and distribution, as well as the medical use of marijuana.

You can learn more about the current legality of marijuana from the Americans for Safe Access website; however, keep in mind that experts still recognize the impairment side effects of marijuana and, regardless of where you live (or have ingested the drug), driving while impaired by marijuana is illegal if you have more than a certain amount of the plant's active ingredient tetrahydrocannabinol (THC) in your system.

Determining Impairment Levels

Aside from states that measure the levels of marijuana in a person's system (see above), no standardized limit for drug impairment exists yet. Of course, similar tests can detect drugs in a person's system, which might help set a standardized limit in the future.

Because of the rise of drug-impaired driving, we can expect these issues to gain increased research, which will undoubtedly result in more concrete, standardized laws in coming years.

Drug-Impaired Driving Laws

As you can see by now, cracking down on driving under the influence of drugs has posed some challenges; however, the government is working to create some laws.

Although the exact definitions and implementations vary by state, the most common statutes so far include those that:

  • Require the drug to make the driver incapable of safe driving.
  • Require the drug to impair the driver's ability to drive safely.
  • Are considered zero tolerance laws, which means it's a criminal offense for the driver to have any drug present in his or her system.

Although the first two statutes are the most common, they pose problems because law enforcement and other government officials must prove the drug caused impaired driving; because the per-se statutes enforce zero tolerance, some government officials feel they help prosecute, convict, and possibly treat drivers who operate motor vehicles with drugs in their systems.

Unsurprisingly, penalties related to driving under the influence of drugs vary just as much as those related to alcohol.

We provide sources that might help you find information specific to your state:

Of course, you can always contact your driver license agency as well as any city, county, or state police officers for current laws in your area.

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