DUI Laws
DUI of Drugs (DUID) in California — Laws, Penalties, and Defenses
California's DUI law covers impairment by any drug — prescription, over-the-counter, or illegal. A DUID conviction carries the same penalties as an alcohol DUI. Learn how drug DUI cases are investigated and how to defend them.
By Michael P. Kade — Former LAPD Officer & Criminal Defense Attorney · Updated
Educational purposes only — not legal advice. This article provides general information about California DUI law and does not create an attorney-client relationship. Consult a licensed attorney for advice specific to your situation.
Key Takeaways
- —California Vehicle Code § 23152(f) makes it unlawful to drive under the influence of any drug
- —There is no per se BAC-style limit for drugs — the prosecution must prove actual impairment
- —Drug Recognition Evaluators (DREs) are used to identify drug impairment at the roadside
- —Prescription drugs can support a DUID charge even if taken as prescribed
- —Blood tests are the primary chemical evidence in drug DUI cases
When most people think of DUI, they think of alcohol. But California Vehicle Code § 23152(f) makes it equally unlawful to drive under the influence of any drug — including prescription medications, over-the-counter drugs, and illegal substances. A DUID conviction carries the same penalties as an alcohol DUI, but the investigation and the defenses are significantly different.
How Drug DUI Is Investigated
Unlike alcohol DUI, there is no roadside breath test for drugs. Officers who suspect drug impairment will typically call a Drug Recognition Evaluator (DRE) — an officer trained in a 12-step protocol developed by the LAPD and adopted by NHTSA. The DRE examines the driver's eyes, vital signs, muscle tone, and other indicators to form an opinion about whether the driver is impaired and, if so, by what category of drug. The DRE's opinion is admissible at trial, but it is also subject to vigorous cross-examination.
Chemical Testing in Drug DUI Cases
Because breath tests do not detect drugs, the primary chemical evidence in a DUID case is a blood test. If the officer suspects drug impairment, they may require a blood draw even if the driver already took a breath test for alcohol. The blood sample is analyzed for the presence of drugs and their metabolites. The presence of a drug in the blood does not automatically prove impairment — many drugs remain detectable in the blood long after their impairing effects have worn off, which is a critical defense argument.
Prescription Drug DUI
A valid prescription is not a defense to a DUID charge. If a prescribed medication impairs your ability to drive safely, you can be convicted of DUI even if you took the medication exactly as directed by your doctor. However, the prosecution must still prove that the drug actually impaired your driving — not merely that it was present in your system. Evidence that you took the medication as prescribed, that your doctor did not warn you about driving impairment, and that your driving was otherwise normal can all support a defense.
Marijuana DUI
Marijuana DUI is charged under Vehicle Code § 23152(f) and is addressed in a separate article on this site. The key challenge in marijuana DUI cases is that THC can remain detectable in the blood for days or weeks after use, long after any impairing effects have dissipated. The prosecution must prove actual impairment at the time of driving, not merely the presence of THC metabolites.
Penalties at a Glance
| Offense / Situation | Potential Penalty |
|---|---|
| First DUID conviction | Same as first alcohol DUI — fines, probation, DUI school, possible jail |
| DUID with injury | Felony — same as VC § 23153 alcohol DUI with injury |
| DUID + alcohol combined | Charged under VC § 23152(g); same penalties as standard DUI |
Penalties shown are general ranges. Actual sentences depend on the specific facts of your case.
How Attorney Kade Defends These Cases
- —Challenge the DRE's qualifications and the scientific validity of the 12-step protocol
- —Attack the blood test results — presence of a drug does not equal impairment
- —Present expert testimony on the pharmacokinetics of the specific drug involved
- —Argue that the drug was taken as prescribed and did not impair driving ability
- —Challenge the traffic stop and the officer's initial observations
- —Cross-examine the DRE on deviations from the required protocol
- —Present evidence of normal driving behavior prior to the stop
Frequently Asked Questions
While you are not legally required to have an attorney, a DUI conviction carries serious consequences — fines, license suspension, possible jail time, and a permanent criminal record. An experienced DUI attorney can challenge the evidence, negotiate with prosecutors, fight your DMV hearing, and potentially get charges reduced or dismissed. The cost of an attorney is almost always less than the long-term cost of a DUI conviction.
A California DUI case typically takes 3 to 12 months to resolve, depending on the county, the complexity of the case, and whether it goes to trial. Misdemeanor DUI cases in Los Angeles County often take 4 to 8 months. Felony DUI cases take longer. Your attorney can give you a more specific estimate based on the facts of your case and the court's current caseload.
After a DUI arrest: (1) Do not make any statements to police beyond identifying yourself. (2) Contact a DUI attorney as soon as possible — ideally within 24 hours. (3) Call the DMV Driver Safety Office within 10 days to request an APS hearing or your license will be automatically suspended. (4) Write down everything you remember about the stop, the tests, and the arrest while it is fresh.