Prescription Drug DUIs in Colorado: Can You Be Arrested for Taking Legal Medication?

Many drivers in Colorado mistakenly believe that DUIs only apply to alcohol or illegal street drugs. The reality is that you can be arrested and convicted for driving under the influence of legally prescribed medication. Whether you are taking Ambien for sleep, Adderall for ADHD, or Vicodin for back pain, if the drug impairs your driving, you are breaking the law.

Police officers in Fort Collins, Pueblo, and Littleton are aggressively trained to look for signs of prescription drug impairment. Fighting a prescription DUI requires proving that your medication did not affect your driving. If you are facing these charges, searching our directory of United States Lawyers is the best way to find a legal advocate to defend your rights.

The Involuntary Intoxication Defense

One of the first questions people ask is: "Can I use involuntary intoxication as a defense?" Under Colo. Rev. Stat. § 18-1-804, involuntary intoxication is recognized as an affirmative defense when a person unknowingly ingests an intoxicating substance or suffers an unanticipated adverse effect. However, establishing this defense for a prescription DUI is exceptionally difficult.

Crucially, under Colo. Rev. Stat. § 42-4-1301(1)(e), the fact that a person is legally entitled to use a prescription medication does not constitute a defense against driving under the influence. Colorado courts hold that if a medication bottle displays a warning label advising against operating machinery, or if a physician cautioned about drowsiness, any resulting impairment is treated as voluntary rather than involuntary intoxication.

DRE (Drug Recognition Expert) Officer Evaluations

Because breathalyzers cannot detect prescription drugs, Colorado law enforcement relies on Drug Recognition Experts (DREs). These are officers who have undergone special training to identify physical signs of drug impairment. A DRE will check your pulse, look at your pupil dilation in a dark room, examine your muscle tone, and look for injection marks.

DREs will categorize your impairment into drug classes, such as central nervous system depressants (like Xanax) or stimulants (like Adderall). A skilled defense attorney will rigorously cross-examine the DRE in court, challenging their subjective conclusions and pointing out that medical conditions-not just drugs-can cause identical physical symptoms.

How to Suppress Flawed Field Sobriety Tests

Standardized Field Sobriety Tests (SFSTs)-like standing on one leg or walking a straight line-were scientifically developed to measure alcohol impairment, not prescription drug effects. If an officer arrests you for a prescription DUI based on these physical tests, your lawyer can file a motion to suppress this evidence. They can argue that a bad knee, age, nervousness, or the specific side effects of your legal medication (like a tremor) made it impossible for you to pass a test designed for alcohol.

Mixing Prescriptions With a Legal Amount of Alcohol

A common trap for drivers in Colorado is having one glass of wine at dinner while taking a prescribed anti-anxiety medication like Valium. Even if your blood alcohol content (BAC) is only 0.02-well below the 0.08 limit-the combination of alcohol and prescription drugs creates a powerful "synergistic effect." Prosecutors heavily target these cases, arguing that the mixture rendered you completely incapable of driving safely.

Step-by-Step Process in Colorado

A prescription DUI follows a distinct evidentiary path compared to an alcohol DUI, relying on blood chemistry rather than breath tests.

Step 1: The Blood Draw

If an officer suspects prescription drug impairment, they will request an evidentiary chemical blood test. The sample is submitted to an accredited laboratory or the Colorado Bureau of Investigation to screen for therapeutic and non-therapeutic levels of pharmaceuticals.

Step 2: Administrative and Criminal Driving Actions

Under Colo. Rev. Stat. § 42-2-126(3), the DMV does not initiate an administrative per se license revocation solely for prescription drug levels if the driver submitted to testing. Instead, license revocation for drug impairment under Colo. Rev. Stat. § 42-2-125 takes effect only upon a criminal conviction. However, if a driver refuses the chemical blood test, the officer issues Form DR 2638, Colorado, Department of Revenue, Express Consent Affidavit and Notice of Revocation, giving the motorist seven days to request an administrative hearing with the Colorado Department of Revenue, Denver to contest an automatic one-year revocation.

Step 3: Going to Court

You will appear in the county court where you were arrested, such as the Arapahoe County Court, Centennial or the Larimer County Court, Fort Collins. Your attorney will gather your medical records and prescriptions to build a defense that the therapeutic levels in your blood did not cause driving impairment.

How Much Does it Cost in Colorado?

Prescription drug DUIs are notoriously complex to defend.

How Long Does the Process Take?

Because blood tests for complex pharmaceuticals take longer to process than simple alcohol or THC tests, you may wait 2 to 4 months just for the toxicology results to return from the lab. From the date of the arrest to a final jury trial, the entire legal process generally takes 6 to 10 months in Colorado.

Frequently Asked Questions (FAQ)