Yes. You can be arrested for DUI or DWAI in Colorado after taking prescription medication, even when the medication was lawfully prescribed and taken according to directions. The central question is whether the medication, alone or combined with alcohol or another substance, affected your ability to drive safely.
A valid prescription can explain why a medication was in your system, but Colorado law does not treat lawful use as an automatic defense. A blood test showing a medication also does not automatically prove that you were impaired while driving. These cases often depend on the full picture, including the reason for the stop, driving behavior, body-camera footage, medical history, dosage timing, roadside testing, toxicology results, and the time between driving and sample collection.
The Law Firm of Mark S. Hanchey and Ben Peterson helps people in Colorado Springs and nearby areas understand drug-related DUI allegations, testing evidence, court procedures, and driver’s license concerns.
A lawful prescription explains why you had access to a medication. It does not automatically prevent a DUI or DWAI charge, and the medication’s presence does not automatically prove impairment.
Colorado DUI Law Covers Prescription Medication 
Colorado Revised Statutes section 42-4-1301 applies when a person drives under the influence of alcohol, one or more drugs, or a combination of substances. Colorado defines DUI as driving after consuming a substance that affects the person to a degree that makes the person substantially incapable, mentally or physically, of exercising clear judgment, sufficient physical control, or due care in the safe operation of a vehicle.
Colorado defines DWAI as driving after consuming a substance that affects the person to the slightest degree so that the person is less able than usual to exercise clear judgment, sufficient physical control, or due care while driving.
The statute also states that legal entitlement to use a drug does not, by itself, provide a defense to DUI or DWAI. An officer may make an arrest when the available facts establish probable cause to believe that a medication or combination of substances impaired the driver.
Colorado DUI statute:
https://colorado.public.law/statutes/crs_42-4-1301
For a focused explanation of drug-impaired driving, visit:
https://hancheylaw.com/colorado-springs-duid-lawyers/
For a broader explanation of Colorado DUI law, visit:
https://hancheylaw.com/understanding-colorado-dui-laws-what-you-need-to-know/
When you need legal help, Mark Hanchey and Ben Peterson are here to guide you through it all. One step at a time. Reach out today for legal support. Get The Law Firm of Mark S. Hanchey and Ben Peterson fighting for you.
With You Every Step of the Journey
Which Prescription Medications May Lead to a DUI Investigation?
Any medication capable of causing impairing side effects may become part of a DUI investigation. The medication does not need to be illegal, misused, or taken in a higher dose than prescribed.
Medication categories that may draw police attention include:
- Opioid pain medications
- Benzodiazepines prescribed for anxiety, seizures, or related conditions
- Sleep medications
- Muscle relaxants
- Certain antidepressants or antipsychotic medications
- Prescription stimulants
- Antihistamines and other medications that may cause drowsiness
- Combinations of prescription drugs, over-the-counter products, alcohol, or cannabis
The effects of a medication can vary from one person to another. A new prescription, a dosage change, limited sleep, illness, missed meals, or interaction with another substance may affect how a driver responds. Warning labels and instructions from a prescribing professional may be relevant, but they do not decide the legal case by themselves.
The National Highway Traffic Safety Administration warns that prescription and over-the-counter medications may affect judgment, coordination, alertness, and reaction time. Drivers should understand how a medication affects them before operating a vehicle.
How a Prescription Medication DUI Arrest May Begin
A drug-related DUI investigation may begin with a traffic stop, collision, or welfare check involving a parked vehicle. An officer may report lane drifting, delayed braking, an unusual turn, inconsistent speed, failure to respond to a traffic signal, or another driving pattern.
After speaking with the driver, the officer may consider observations such as:
- Speech, balance, eye appearance, or coordination
- Difficulty locating a driver’s license, registration, or insurance card
- Confusion about questions or instructions
- Statements about medication, dosage, or timing
- Prescription containers inside the vehicle
- Performance on roadside coordination exercises
- Information from passengers, witnesses, or medical personnel
- Body-camera or dash-camera footage
No single observation necessarily proves impairment. Anxiety, fatigue, pain, injury, a medical condition, poor lighting, uneven pavement, or unclear instructions may affect how a person appears during a roadside encounter.
Bridgette Carabajal I've had the pleasure of working with Mr. Hanchey on two occasions, and each interaction has been nothing short of exceptional. His professional demeanor, coupled with the outstanding support from his staff significantly alleviated any anxieties I had. I am thoroughly satisfied with the outcomes achieved. Should the need for legal representation arise in the future, Mr. Hanchey will undoubtedly be my first choice. Lucas Garcia Mark Hanchey has been excellent. I spoke with him last minute before my court date. He still showed up to court with me and was very caring and helped me before I had even officially hired him. I felt like he cared about me and my case. He knows his craft very well and you can tell that the judge and other attorneys respect him when he is in court. He is also very kind. I recommend him to anyone. An excellent attorney. Renee Braucht I had an amazing experience with the Hanchey Law Firm! Mr. Hanchey got me the absolute best result I could have imagined for my case. I can’t even tell you how many times I’ve heard, “wow, you must have had a really good lawyer!” when discussing the result. I live far from Colorado Springs, but I will forever make the trip for this firm when I need them! Highly recommend! David Walker I have needed to use a lawyer a couple of times over the past several years and have used Mark Hanchey. He is a very down to earth person who has always treated me with dignity and has always been straight forward. His staff has also been professional and friendly. Each time I used Mark Hanchey the result was a positive one. I also think his fees are reasonable. I cant say enough good about Mark Hanchey.
Can Police Use Field Sobriety Tests in Prescription Drug Cases?
Police may ask a driver to complete roadside exercises when alcohol is not the primary concern. Officers may use divided-attention tasks, eye examinations, balance exercises, and other observations when deciding whether probable cause exists.
These exercises do not measure the effects of every prescription medication. A person with a back injury, neurological condition, anxiety disorder, limited mobility, or vision problem may perform poorly for reasons unrelated to drug impairment. Video may confirm the officer’s description, contradict it, or reveal details that the written report does not include.
An officer may also request an evaluation by a Drug Recognition Expert, commonly called a DRE. A standardized DRE evaluation may include pulse readings, eye examinations, divided-attention tests, vital signs, muscle-tone observations, an interview, and a request for a toxicology sample. The protocol is intended to help the officer assess possible impairment, consider whether a medical condition may be involved, and identify a possible drug category.
A DRE opinion is evidence. It does not automatically establish guilt, and it may be evaluated against medical records, laboratory findings, video evidence, and other facts.
Information about the standardized DRE process is available from the International Association of Chiefs of Police:
https://www.theiacp.org/12-step-process
What Does a Positive Blood Test Mean?
Colorado’s Expressed Consent Law may require a driver to provide a blood, urine, or saliva sample when an officer has probable cause to believe that the driver operated a vehicle while impaired by one or more drugs and the requested test is reasonable. Prescription medication cases commonly involve blood testing.
A toxicology report may identify an active drug, a metabolite, or a reported concentration. For most prescription medications, Colorado does not use one universal numerical level that automatically proves impairment. The prosecution may try to connect the laboratory result with the officer’s observations, driving pattern, statements, medical information, and timing of the sample.
A defense review may ask:
- Was the sample collected, labeled, stored, transported, and tested correctly?
- Did the result identify an active substance, a metabolite, or both?
- How much time passed between driving and sample collection?
- Was the reported concentration consistent with prescribed use?
- Could another medication or medical condition explain the observations?
- Did the laboratory test for the substance the officer claimed caused impairment?
- Does the video support the officer’s written report?
- Did multiple substances complicate the toxicology interpretation?
- Did the laboratory use reliable procedures and appropriate quality controls?
- Is expert interpretation needed to explain what the result can and cannot establish?
A positive result can show that a medication or metabolite was present. It may not establish when the medication was taken, how strongly it affected the driver, or whether it caused unsafe driving.
Colorado Expressed Consent statute:
https://colorado.public.law/statutes/crs_42-4-1301.1
What Happens After a Prescription Medication DUI Arrest?
A Colorado DUI arrest can create two separate proceedings. The criminal case moves through the court system. A separate administrative proceeding may affect driving privileges through the Colorado Division of Motor Vehicles. The two tracks operate independently, so a criminal court date does not automatically protect a driver’s license.
Expressed Consent paperwork can include a short deadline. The Colorado DMV states that a driver may have up to seven days to request a hearing after receiving an Expressed Consent Affidavit and Notice of Revocation or a mailed Notice of Revocation. The deadline and procedure depend on how notice was issued, so every document should be reviewed promptly.
Colorado DMV Expressed Consent hearing information:
https://cdor.colorado.gov/express-consent-cases-procedures
The criminal case may involve an advisement, evidence requests, pretrial conferences, motions, negotiations, and trial preparation. Potential consequences depend on the charge, prior record, evidence, and aggravating facts. They may include jail, probation, fines and costs, useful public service, alcohol or drug education, treatment, license restrictions, and effects on employment or professional licensing.
For more information about possible DUID consequences, visit:
https://hancheylaw.com/understanding-the-legal-consequences-of-a-duid-conviction-in-colorado/
Possible Defense Issues in a Prescription Medication DUI Case
A valid prescription is relevant, but a defense usually requires more than showing a prescription bottle. The central question is whether the prosecution can prove every required element of DUI or DWAI with reliable evidence.
Potential defense issues may include:
- The officer lacked a lawful basis for the traffic stop or detention.
- The arrest was not supported by probable cause.
- The officer misinterpreted symptoms caused by illness, injury, fatigue, anxiety, or another medical issue.
- Roadside exercises were unsuitable for the driver or administered incorrectly.
- Body-camera or dash-camera footage does not support the written report.
- A medication was detected, but the evidence does not connect it to impaired driving.
- The blood draw, sample handling, or laboratory process was unreliable.
- The chain of custody contains gaps or documentation problems.
- The DRE opinion conflicts with medical records, video, or toxicology findings.
- The reported concentration requires expert interpretation.
- Another substance, medical event, or environmental condition better explains the observations.
No defense applies to every case. An attorney can compare the officer’s conclusions with the video, laboratory records, prescription history, medical information, and applicable law.
For more information about DUID defenses, visit:
https://hancheylaw.com/common-defenses-against-duid-charges-in-colorado/
What Should You Do After an Arrest?
Protect accurate information and avoid public explanations.
- Keep every citation, bond document, test notice, prescription record, pharmacy printout, and court paper.
- Write a private timeline showing when you took medication, ate, slept, drove, and encountered police.
- Preserve receipts, messages, location records, photographs, and witness information.
- Do not post about the arrest or the underlying events on social media.
- Do not stop or change prescribed medication without speaking with the prescribing medical professional.
- Follow every bond condition and attend every court date.
- Review DMV notices immediately.
- Avoid making additional statements about the case before receiving legal advice.
- Speak with a Colorado DUI defense attorney as soon as possible.
Speak With a Colorado Springs DUI Attorney
A prescription medication DUI arrest can be confusing, especially when you followed medical instructions. The Law Firm of Mark S. Hanchey and Ben Peterson can review the traffic stop, medical history, roadside testing, toxicology evidence, DMV paperwork, and criminal charge without promising a particular result.
The firm represents people in Colorado Springs, El Paso County, and nearby areas. It offers free consultations and provides criminal defense guidance based on the facts of each case.
