DUI Drug Charges in Kentucky (Marijuana, Prescription,...

A DUI charge in Kentucky does not require alcohol. Under KRS 189A.010(1)(c), it is illegal to operate a motor vehicle while under the influence of any substance that impairs driving ability — including marijuana, prescription medications, and illicit drugs. Drug DUI cases present unique evidentiary challenges, and Clark + Harris represents clients facing drug DUI charges throughout Kentucky, including Lexington, Louisville, and every jurisdiction in between.

The Kentucky Drug DUI Statute

KRS 189A.010(1)(c) makes it unlawful to operate or be in physical control of a motor vehicle while under the influence of any other substance or combination of substances which impairs one’s driving ability. KRS 189A.010(1)(d) applies specifically to the presence of a Schedule I or II controlled substance. Unlike alcohol DUI, there is no per se threshold — the Commonwealth must prove actual impairment.

Marijuana DUI Cases

Marijuana DUI cases have grown in frequency as medical marijuana becomes more widely accepted and CBD and delta-8 products are increasingly available. Marijuana metabolites can be detected in blood days or weeks after use, long after any impairing effect has passed. This creates a challenge for the Commonwealth, which must prove impairment at the time of driving rather than mere presence of metabolites.

Key defense issues in marijuana DUI cases:

Timing of ingestion: Was the marijuana consumed hours, days, or weeks ago?
Tolerance: Regular users metabolize marijuana differently than occasional users.
Blood testing methodology: Kentucky State Police lab protocols and analyst credentials
Drug recognition expert (DRE) evaluations: These require specific training and protocol adherence

Prescription Medication DUI

Prescription drug DUI is particularly complex. Patients taking prescribed medications — opioids, benzodiazepines, antidepressants, sleep aids, muscle relaxants — may find themselves charged with DUI even when taking medications as prescribed. KRS 189A.010(1)(c) does not exempt legally prescribed medications if they impair driving.

Defenses often include:

Proper dosage and timing: Was the medication taken as prescribed?
Therapeutic level testing: Was the blood concentration within the therapeutic range?
Tolerance: Had the patient developed tolerance to the medication?
Officer training: Did the officer recognize potential medical conditions that mimicked impairment?

Illicit Drug DUI Cases

Illicit drug DUI cases involve substances such as methamphetamine, cocaine, heroin, fentanyl, and others. The Commonwealth typically proves impairment through:

Officer observations of behavior, speech, and physical appearance
Drug recognition expert (DRE) evaluations
Blood or urine testing
Admissions made by the defendant
Physical evidence of drug use found in the vehicle

Drug Recognition Experts

Kentucky has officers trained as drug recognition experts (DREs) under the International Association of Chiefs of Police protocol. DREs conduct a 12-step evaluation that includes breath testing, interview with the arresting officer, preliminary examination, eye examinations, divided attention tests, vital signs, dark room examinations, muscle tone assessment, injection site examination, suspect statements, opinion, and toxicology.

DRE evaluations are vulnerable to challenge on multiple fronts: certification, protocol adherence, and the subjective nature of many of the observations. We have successfully challenged DRE opinions in Kentucky DUI cases.

Blood Testing in Drug DUI Cases

Drug DUI cases typically rely on blood testing rather than breath. The blood must be collected by qualified personnel, preserved properly, and analyzed by a qualified laboratory. We review Kentucky State Police lab protocols, analyst credentials, chain-of-custody documentation, and the scientific reliability of the testing methodology.

Aggravating Circumstances in Drug DUI

All six aggravators under KRS 189A.010(11) apply to drug DUI cases, including the child passenger, refusal, and accident-resulting-in-injury aggravators. The BAC-specific aggravator does not apply to drug cases, but the refusal aggravator may apply if the driver refused blood testing.

Call Clark + Harris

If you have been charged with a drug DUI in Kentucky, the stakes are high and the evidence is complex. Call Clark + Harris at 859-474-0001 for a confidential consultation. Our attorneys defend drug DUI cases across Kentucky, from Lexington to Louisville to every rural courthouse in between.

Frequently Asked Questions

How soon should I contact Clark + Harris after being charged in Kentucky?

As soon as possible. Early representation protects your rights during questioning, preserves evidence, and often leads to better outcomes. Call 859-474-0001 — we respond promptly to new inquiries.

Does Clark + Harris represent clients throughout Kentucky?

Yes. We represent clients in all 120 Kentucky counties, both state District and Circuit courts, and federal courts in the Eastern and Western Districts of Kentucky.

What happens during a free consultation with Clark + Harris?

We review the specific charges and evidence, discuss available defenses, explain the likely process in the relevant court, and give you a clear roadmap of next steps — at no cost to you.

Related Resources

If this information applied to your situation, the following Clark + Harris guides may also be helpful:

DUI Drug Charges in Kentucky (Marijuana, Prescription, Illicit)