Can I Get a DUI in Illinois By Driving on Prescription Medication?

Why Following Your Doctor’s Orders Isn’t Always a Legal Shield in DUI Cases

In Illinois, DUI laws are often associated with alcohol or illegal drug use. But what many drivers across Chicago have learned the hard way is that you can also be charged with DUI for driving after taking prescription medication. Even if that medication was legally prescribed and taken exactly as directed, you can still face arrest, prosecution, and serious criminal penalties.

Prescription medication DUI cases are not uncommon in Cook County courts. In fact, more officers today are being trained to spot signs of drug impairment, and prosecutors are increasingly pursuing these charges—even when there’s no evidence of alcohol or illegal substances.

If you’ve been charged with DUI based on a medication you legally take for pain, anxiety, ADHD, or sleep, you might feel confused or even betrayed by a system that’s supposed to protect people who follow the rules. But there is a path forward. And that path starts with understanding the law and getting the right legal representation as early as possible.

Legal Medication Can Still Lead to Criminal Charges

The key to understanding these cases is knowing how Illinois defines DUI. Under 625 ILCS 5/11-501(a)(4), a person is guilty of DUI if they are “under the influence of any other drug or combination of drugs to a degree that renders the person incapable of safely driving.”

The statute doesn’t care whether the drug is legal or not. The question is whether it impaired your ability to operate a vehicle. That includes medications prescribed by your doctor—even if you were told they were safe to use.

The most common types of medications involved in DUI cases include:

Benzodiazepines (like Xanax, Valium, or Ativan)
Opioid painkillers (such as Oxycodone or Hydrocodone)
Sleep aids (Ambien, Lunesta)
Stimulants for ADHD (Adderall, Ritalin)
Anti-anxiety or depression medications

Even over-the-counter medications like cold or allergy medicine can cause drowsiness and impair driving—leading to DUI arrests in some cases.

How Police Handle DUI Stops Involving Prescription Drugs

In Chicago, prescription drug DUI arrests often follow a routine traffic stop. An officer may notice erratic driving, speeding, lane drifting, or failure to signal. During the stop, if the officer observes slow responses, slurred speech, or confusion, they may begin a DUI investigation.

If there’s no smell of alcohol, the officer may start asking about drug use or prescription medications. Many drivers, trying to be honest, admit to taking something. That statement—though made in good faith—often becomes the cornerstone of the State’s case.

Unlike alcohol DUI stops, there may be no breathalyzer involved. Instead, the officer may request a blood or urine test. They may also involve a Drug Recognition Expert (DRE) to conduct a physical evaluation and look for signs of impairment.

If the officer believes the medication impaired your driving, they will arrest you and charge you with DUI.

What the State Needs to Prove

To convict you of DUI based on prescription drugs, prosecutors need to prove that:

You were in actual physical control of a motor vehicle
You were impaired by a drug (even a legal one)
The level of impairment made you incapable of driving safely

There’s no requirement for the prosecution to prove intoxication at a particular level, like with alcohol. There’s no “.08” threshold. Instead, the case usually hinges on subjective evidence: what the officer saw, what you said, how you acted, and what the drug test showed.

This gives your attorney a lot of room to raise reasonable doubt—but only if they understand how to take advantage of it.

Why These Cases Are Often Defensible

Prescription drug DUI cases can be difficult for the State to prove. That’s because:

Prescription medications affect everyone differently
There’s no “legal limit” for prescription drug levels in the bloodstream
Officers are not always qualified to assess drug impairment
Lab tests only show presence of the drug—not impairment
Behavior at the time of arrest may have other explanations (fatigue, anxiety, illness)

A knowledgeable DUI defense attorney can challenge each part of the State’s case. They can cross-examine the Drug Recognition Expert, scrutinize test results, and introduce alternative explanations for your behavior. They may also present expert medical testimony to show that your prescription dose was well within therapeutic limits and not likely to impair driving.

What Happens After You’re Arrested

Once you’re arrested for DUI in Chicago, you’ll typically be booked, fingerprinted, and given a court date. You may also face a statutory summary suspension of your driver’s license under 625 ILCS 5/11-501.1 if you refused chemical testing or if the results indicated drug presence.

At your first court appearance, the judge will advise you of the charges and your rights. From there, your attorney can file motions to contest the traffic stop, suppress evidence, and challenge the validity of the arrest.

The prosecution will provide police reports, lab results, and any other evidence they intend to use. Your attorney will evaluate this material and decide whether to negotiate a plea, pursue court supervision, or fight the charge at trial.

Penalties for DUI Based on Prescription Medication

The penalties for prescription drug DUIs are the same as for any DUI in Illinois. For a first offense, it is a Class A misdemeanor, which carries:

Up to 364 days in jail
A fine of up to $2,500
Driver’s license suspension
Court supervision (if eligible)
Mandatory drug or alcohol education
Possible ignition interlock device (if alcohol was also involved)

A second offense or DUI with aggravating factors may be filed as a Class 4 felony or higher, depending on the situation. Penalties increase sharply if you caused an accident, had a child in the car, or were driving on a suspended license.

Even without jail time, a DUI conviction will remain on your criminal record permanently and can affect employment, housing, insurance rates, and your professional reputation.

Building a Strong Legal Defense

A prescription drug DUI defense is built on three fronts: medical facts, legal arguments, and procedural challenges. Your attorney should look for:

Invalid or unlawful traffic stop
Inaccurate or incomplete DRE evaluation
Lack of clear signs of impairment
Alternative explanations for symptoms
Medication dosage and time of ingestion
Chain of custody issues with blood or urine tests
Absence of warnings on the prescription label

Many drivers take their prescriptions exactly as prescribed and remain fully capable of driving. But officers are not medical professionals, and their assessments are often flawed.

Your attorney may also seek to negotiate a reduced charge (such as reckless driving) or secure court supervision that avoids a conviction entirely.

Why You Need a Lawyer—Even If You Followed Doctor’s Orders

It’s easy to believe that the court will understand your situation. After all, you were just following medical advice. But prosecutors won’t drop charges just because you had a prescription. And judges won’t ignore police testimony without solid legal arguments.

If you try to represent yourself, or rely on a public defender with limited time, you may miss key opportunities to challenge the evidence. You could end up with a permanent record, loss of your license, and ongoing costs for years to come.

Hiring a DUI lawyer means putting someone on your side who knows how to dismantle the State’s case, protect your record, and help you move on without life-changing consequences.

Get Help From a Chicago DUI Attorney Who Understands Prescription Cases

At The Law Offices of David L. Freidberg, we’ve been defending clients in DUI cases for decades. We understand how prosecutors build prescription DUI charges—and more importantly, how to fight them.

We work with toxicologists, cross-examine DRE officers, and file aggressive motions to suppress flawed evidence. We handle cases throughout Cook County and the surrounding areas, including DuPage, Will, and Lake Counties.

Call Now – The Law Offices of David L. Freidberg Is Ready to Help

If you were arrested in Chicago for DUI, protect your future by contacting The Law Offices of David L. Freidberg. We have decades of experience handling DUI cases in Illinois. Our firm is available 24/7 to provide the legal defense you deserve.

Contact us today at (312) 560-7100 or toll-free at (800) 803-1442 for a free consultation. We’re available 24/7 to serve clients throughout Illinois, Cook County, DuPage County, Will County, and Lake County.