Many people assume that DUI charges only apply to alcohol or illegal drugs, but that’s not the case. In California, you can be charged with DUI if you are impaired by prescription or over-the-counter (OTC) medications, even if they were legally obtained and taken as directed.

So, how does the law treat these cases? What substances can lead to a DUI, and what should you do if you’re facing charges? Here’s everything you need to know.

DUI vs. DWI in California: Is There a Difference?

You might hear the terms DUI (Driving Under the Influence) and DWI (Driving While Intoxicated/Impaired) used interchangeably, but in California, the law only recognizes DUI. The state does not differentiate between DUI and DWI—any impairment from alcohol, drugs, or a combination of both is classified as DUI.

This means that whether you’re impaired by alcohol, illegal drugs, prescription medication, or even OTC cold medicine, the charge will still fall under California’s DUI laws.

California Law on DUI and Prescription/OTC Drugs

California law states that it is illegal to drive under the influence of any drug if it impairs your ability to operate a vehicle safely. The key factor is impairment, not whether the drug was legally obtained.

California Vehicle Code § 23152(f) makes it unlawful to drive while under the influence of any drug, including legally prescribed medication or OTC drugs.
California Vehicle Code § 23152(g) states that driving under the combined influence of alcohol and drugs is also illegal.

There is no legal threshold for drug impairment like the 0.08% BAC limit for alcohol. Instead, law enforcement officers determine impairment based on behavior, field sobriety tests, and chemical testing.

Even medications that are legally prescribed can slow reaction time, cause drowsiness, or impair judgment, making them risky for driving.

How Do Police Determine Prescription Drug Impairment?

Since there is no “legal limit” for drugs, officers use a variety of methods to assess whether a driver is impaired by medication, including:

1. Field Sobriety Tests (FSTs)

Officers may ask you to perform tests like the walk-and-turn, one-leg stand, or horizontal gaze nystagmus test to check balance, coordination, and reaction time.
Poor performance may be taken as a sign of impairment, but these tests are not always accurate—medical conditions, fatigue, or nervousness can affect the results.

2. Drug Recognition Expert (DRE) Evaluation

A Drug Recognition Expert (DRE) may be called to evaluate signs of drug impairment.
This includes checking pupil size, eye movement, pulse, blood pressure, and overall behavior.

3. Blood or Urine Tests

If drug impairment is suspected, a blood or urine test will be administered to detect the presence of medications.
However, these tests can only confirm the presence of a drug, not necessarily whether the driver was impaired at the time.

4. Driving Behavior and Physical Observations

Erratic driving (weaving, speeding, or slow responses) is often used as initial evidence of impairment.
Physical signs such as drowsiness, confusion, slurred speech, or delayed reactions may also be noted in a police report.

If you refuse a chemical test after being arrested, you could face an automatic one-year license suspension under California’s implied consent laws.

Common Prescription and OTC Drugs That Can Lead to DUI Charges

Many prescription and OTC drugs can impair alertness, coordination, and judgment—even when taken as directed. Some of the most common medications involved in DUI cases include:

Prescription Medications

Opioid Painkillers: Oxycodone, Hydrocodone (Vicodin), Morphine, Fentanyl
Anti-Anxiety Medications: Alprazolam (Xanax), Lorazepam (Ativan), Diazepam (Valium)
Sleep Aids: Zolpidem (Ambien), Eszopiclone (Lunesta)
Antidepressants: Tricyclic antidepressants (Amitriptyline, Doxepin)
Muscle Relaxants: Carisoprodol (Soma), Cyclobenzaprine (Flexeril)
ADHD Medications: Adderall, Ritalin (in high doses, can lead to erratic driving)

Over-the-Counter Medications

Antihistamines: Diphenhydramine (Benadryl), commonly found in cold and allergy medications
Cold & Flu Medications: NyQuil, DayQuil (especially those containing alcohol or sedatives)
Cough Syrups: Dextromethorphan-based cough medicines
Motion Sickness Pills: Meclizine (Dramamine), which can cause drowsiness

Even non-drowsy formulas can impair reaction time or focus in some individuals. Always read medication labels before driving.

Penalties for a Prescription Drug DUI in California

A DUI for prescription or OTC drugs carries the same penalties as an alcohol-related DUI. The severity of the punishment depends on prior offenses and whether injuries were involved.

First-Offense DUI (Misdemeanor)

Fines: $390 – $1,000 (plus court fees and penalty assessments)
Jail Time: Up to 6 months in county jail
License Suspension: 6 months (or 1 year if you refused a chemical test)
DUI School: Mandatory 3- to 9-month drug and alcohol education program
Probation: 3–5 years

Second or Third DUI (Within 10 Years)

Increased fines and mandatory jail time (minimum of 96 hours for a second offense, 120 days for a third)
Longer license suspension (2–3 years)
18- to 30-month DUI education program
Possible ignition interlock device (IID) requirement

Felony DUI (If Injury or Multiple Offenses)

State prison sentence (16 months to 4 years)
License revocation (4+ years or permanent in extreme cases)
High fines and restitution if injuries occurred

These penalties apply regardless of whether the drugs were legally prescribed—what matters is whether they impaired your ability to drive safely.

Legal Defenses for a Prescription Drug DUI

If you’re charged with DUI due to prescription or OTC drug use, there are several possible defenses:

1. No Actual Impairment

Simply having a drug in your system is not enough to prove impairment.
Your attorney may argue that you took the medication correctly and were driving safely.

2. Faulty Field Sobriety or DRE Tests

Field sobriety tests are subjective and can be affected by medical conditions, fatigue, or stress.
A Drug Recognition Expert’s assessment can be challenged if bias or mistakes were involved.

3. Blood Test Results Do Not Prove Impairment

Blood tests can detect drugs long after their effects have worn off.
A medical expert may testify that the levels detected were not enough to impair driving.

4. Lack of Probable Cause for Arrest

If the police stopped you without valid reason, evidence may be inadmissible in court.
An attorney may challenge whether the officer had probable cause to conduct a DUI investigation.

Final Thoughts: Know the Risks Before Driving on Medication

A DUI involving prescription or OTC drugs is just as serious as an alcohol-related DUI in California. Even if you legally obtained and correctly used the medication, you can be arrested and charged if it impairs your driving.

To reduce your risk:
✅ Read medication labels carefully for warnings about drowsiness or impaired driving.
✅ Avoid driving until you know how a new medication affects you.
✅ Ask your doctor if your prescription could impact driving ability.
✅ Use public transportation, rideshare, or a designated driver if feeling impaired.

If you or a loved one is facing a DUI charge for prescription or OTC drug use, it’s critical to seek legal guidance immediately. A skilled DUI attorney can assess your case, challenge the evidence, and fight for the best possible outcome.

What to Do If You’re Facing a Prescription Drug DUI Charge

At Jackson Bibby Awareness Group, we understand how overwhelming and stressful DUI charges can be. We offer state-approved DUI education programs designed to help individuals comply with court orders, fulfill DMV requirements, and move forward after a DUI conviction.

Why Choose Jackson Bibby?

✅ State-licensed DUI programs for first and multiple offenders
✅ Flexible scheduling with in-person and virtual options
✅ Supportive environment to help you complete your required program
✅ Convenient locations across California

Don’t wait until it’s too late! If you need to enroll in a DUI program, contact Jackson Bibby Awareness Group today.

📞 Call us now at (909) 792-6925

Can You Be Charged with DUI for Prescription or Over-the-Counter Drugs in California?