Drugged Driving (Drug DUI) — Florida § 316.193

Florida Statute § 316.193 makes it a crime to drive under the influence of “any chemical substance set forth in § 877.111 or any substance controlled under chapter 893” — covering marijuana, cocaine, prescription opioids, benzodiazepines, and hundreds of other drugs. Unlike alcohol, there is no per se impairment limit for drugs. The prosecution must prove your normal faculties were actually impaired at the time of driving, and that proof usually turns on contested toxicology. Call (863) 774-4556 now.

Legally reviewed by Tonmiel Rodriguez, Board Certified Criminal Trial Lawyer — last reviewed June 2026.

How Does Florida’s DUI Statute Apply to Drugs?

Florida’s DUI statute, § 316.193, does not distinguish between alcohol and drug impairment. It prohibits driving “under the influence of alcoholic beverages, any chemical substance set forth in § 877.111, or any substance controlled under chapter 893” when that influence impairs the person’s normal faculties. Chapter 893 covers Florida’s entire schedule of controlled substances — Schedule I through Schedule V — and § 877.111 covers volatile chemical substances. The practical effect is that any drug, legal or illegal, prescribed or not, can be the basis for a DUI charge if the State can prove it impaired your driving.

The critical difference from alcohol DUI: there is no .08 equivalent for drugs. No per se limit. The State cannot simply point to a blood level and declare it presumptively intoxicating. They must prove actual impairment — meaning your normal faculties were impaired at the time you were driving. That requirement is a significant opportunity for the defense.

What Does the State Have to Prove in a Drug DUI Case?

To convict on a drug DUI under § 316.193, the State must prove beyond a reasonable doubt:

• You were driving or in actual physical control of a vehicle
• You were under the influence of a chemical substance listed in § 877.111 or a controlled substance under chapter 893
• The substance impaired your normal faculties — ability to see, hear, walk, talk, judge distances, drive, or act in an emergency

Element 3 is where drug DUI cases are won and lost. The State must connect the drug found in your system to actual impaired driving ability at the specific time you were behind the wheel. A positive test result is evidence — but it is not proof of impairment without more.

What Is a Drug Recognition Expert (DRE) and Can Their Testimony Be Challenged?

A Drug Recognition Expert is a law enforcement officer who has completed specialized training — typically 72 classroom hours plus field certification — in a 12-step evaluation protocol developed by the International Association of Chiefs of Police. The 12 steps include: breath test, interview of the arresting officer, preliminary examination, eye examination, divided attention tests, vital signs examination, dark room examinations (pupil size and muscle tone), nasal and oral cavity examination, and toxicology review.

DRE evidence is admitted in Florida courts, but it is not bulletproof. Peer-reviewed scientific literature has raised serious questions about the protocol’s reliability — including a 2020 NHTSA-sponsored validation study that found DRE conclusions about specific drug categories were accurate approximately 44–72% of the time depending on the drug category. That is a significant error rate for evidence used to convict people of crimes. I challenge DRE testimony by:

• Subpoenaing the officer’s training and certification records to identify any gaps
• Reviewing the evaluation documentation for deviations from the 12-step protocol
• Engaging toxicology experts to challenge the scientific validity of the methodology
• Presenting alternative explanations for every physical observation the DRE made

Can I Be Convicted of Marijuana DUI if I Wasn’t High When I Was Driving?

No — not based on metabolite detection alone. THC metabolites are detectable in urine for up to 30 days after use in regular users. The presence of THC-COOH (the inactive metabolite detected in urine) says nothing about whether you were impaired at the time of driving. Florida courts have recognized this distinction: impairment at the time of driving must be established by independent evidence beyond a mere positive test result.

Blood tests are more complex. Blood can detect THC (the active compound) more recently than urine, but there is no scientifically established blood concentration level that proves impairment in all individuals. Tolerance, frequency of use, body weight, and metabolism all affect the relationship between blood THC levels and actual impairment. Expert toxicology testimony is critical in marijuana DUI cases.

Does a Valid Prescription Protect Me From a Drug DUI Charge?

It is a defense — but not an automatic one. Florida Statute § 316.193 does not carve out an exception for lawfully prescribed medications. The defense argument is a two-part showing: (1) you had a valid prescription for the medication, and (2) you were not actually impaired at the time of driving. If both elements are established, the State should not prevail.

The challenge is that the State will argue the medication impaired you even if you followed the prescribed dosage. This is where medical expert testimony becomes critical — a physician familiar with the pharmacology of the specific drug, your dosage, and the evidence in your case can provide testimony about whether therapeutic doses of that medication cause the type of impairment the officer observed.

Blood Testing Issues in Drug DUI Cases

When a DUI arrest involves drug impairment, law enforcement typically seeks a blood draw rather than a breath test — because the Intoxilyzer measures alcohol only. Blood draws in Florida must comply with § 316.1932, which requires the draw be performed by specified medical personnel in a medically accepted manner. Violations of these requirements can result in suppression of the blood evidence.

Beyond the draw itself, I examine:

• Chain of custody — was the sample properly handled, labeled, refrigerated, and delivered to the lab?
• Lab accreditation and procedures — was the analyzing laboratory FDLE-certified? Were proper protocols followed?
• Sample integrity — was the tube properly preserved with the correct anticoagulant and fluoride? Degradation can affect drug levels
• Analyst qualifications — was the report prepared by a qualified forensic toxicologist?
• Retrograde and extrapolation issues — were any calculations made about drug levels at the time of driving versus the time of the draw?

What Are the Penalties for Drug DUI in Florida?

Drug DUI is charged under the same statute and carries the same penalties as alcohol DUI under § 316.193:

• First offense: Up to 6 months in jail, $500–$1,000 fine, 6–12 month license revocation, 50 hours community service, 1 year probation, DUI school, ignition interlock if BAC was .15+ (though BAC doesn’t apply to drugs, interlock may still be ordered)
• Second offense within 5 years: Mandatory 10-day jail minimum, up to 9 months jail, $1,000–$2,000 fine, 5-year license revocation, mandatory ignition interlock for 2 years
• Third offense within 10 years: Third-degree felony, up to 5 years prison, $2,000–$5,000 fine, 10-year license revocation
• Mandatory adjudication on any DUI conviction — § 316.193(6) prohibits withheld adjudication

Frequently Asked Questions — Drug DUI in Florida

Can I be charged with DUI for drugs if I have a valid prescription?

Yes. Florida Statute § 316.193 does not exempt lawfully prescribed medications. However, a valid prescription is a meaningful defense: it establishes that your use was lawful, and the State must still prove your normal faculties were actually impaired at the time of driving. Lawful use plus no actual impairment equals no DUI — but establishing the absence of impairment requires medical expert testimony in most cases.

Is a positive marijuana urine test proof of DUI in Florida?

No. Florida law requires proof of actual impairment at the time of driving — not just the presence of THC metabolites. THC-COOH, the inactive metabolite detected in urine, remains detectable for up to 30 days after use and provides no information about impairment at a specific time. A positive urine test without additional evidence of impairment is insufficient to sustain a drug DUI conviction.

What is a Drug Recognition Expert and how do you challenge their testimony?

A DRE is a law enforcement officer trained in a 12-step protocol to identify drug impairment. The methodology is scientifically contested — accuracy rates in peer-reviewed studies range from 44–72% depending on the drug category. I challenge DRE testimony by attacking the officer’s training records, deviations from protocol, the scientific validity of the methodology, and by presenting expert toxicology testimony offering alternative explanations for the physical observations.

What drugs can lead to a DUI charge in Florida?

Any chemical substance listed in § 877.111 and any controlled substance under chapter 893 — including marijuana, cocaine, heroin, methamphetamine, prescription opioids, benzodiazepines, muscle relaxants, and sleep aids. There is no per se impairment limit for any of these drugs. The State must prove actual impairment in every drug DUI case.

Why is there no breath test for drug DUI?

Florida’s Intoxilyzer 8000 measures alcohol in breath — it does not detect drugs. For drug DUI, law enforcement relies on urine testing and blood testing. A urine result shows past use rather than impairment at the wheel, and even a blood level requires expert interpretation to connect it to actual impairment. Because there is no standardized per se limit, drug DUI cases turn on contested toxicology, which gives the defense more room to challenge the State’s proof than in a typical alcohol DUI.

Drug Categories and DRE Impairment Indicators

The DRE protocol is designed to identify impairment by seven drug categories: central nervous system (CNS) depressants, CNS stimulants, hallucinogens, dissociative anesthetics, narcotic analgesics, inhalants, and cannabis. Each category produces different physiological markers — pulse rate, pupil size and reaction, blood pressure, muscle tone, and eye movement — that the DRE is trained to associate with impairment by that drug class. The protocol is not designed to identify a specific drug or confirm a specific dose; it produces a category opinion at best.

The defense challenge is that many of the physical indicators the DRE attributes to drug impairment have innocent explanations: elevated pulse and blood pressure from anxiety during a police encounter; constricted pupils from bright light exposure; muscle tension from stress; slow pupil response from fatigue. The DRE protocol does not control for these alternative explanations and relies almost entirely on the officer’s subjective interpretation of observations that are simultaneously explained by non-impairment causes.

Metabolite vs. Active Impairment — Why the Distinction Matters

Drug DUI defense often turns on the difference between an active drug compound and its inactive metabolites. When your body processes a drug, it breaks it down into metabolites — chemical byproducts that persist in blood, urine, and other fluids long after the pharmacologically active compound is gone. A urine test detects metabolites. A blood test may detect either the active compound or its metabolites, depending on how much time has passed.

For cannabis specifically: THC (the active compound) has a blood half-life of approximately 3–12 hours. THC-COOH (the primary inactive metabolite detected in urine) has a half-life of 5–13 days in regular users. A person who used marijuana 3 weeks ago may test positive on a urine screen while having zero active THC in their blood and zero impairment while driving. For prescription opioids and benzodiazepines, similar dynamics apply — metabolites of many long-acting medications are detectable for days to weeks after the last therapeutic dose, while actual clinical impairment ends much sooner.

The relevance to Florida DUI law: the state must prove impairment at the time of driving. A metabolite in urine demonstrates past exposure — not current impairment. When the state’s evidence of drug impairment rests primarily on a metabolite-positive urine test, the defense has a strong scientific argument that no impairment was present at the time of driving.

Polydrug Impairment and Combination Drug Cases

Cases involving multiple drugs — or a combination of drugs and alcohol — present the most complex drug DUI scenarios. When two or more substances are found in a blood sample, the state may argue that the combination produced impairment even when individual drug levels were below any clinically significant threshold. That “polydrug” argument invites a direct response: the State cannot say which drug impaired the driver, at what concentration, or in what combination. Without expert pharmacology testimony establishing the combined effect of specific drugs at specific concentrations in this specific individual, the polydrug argument is speculation, not science. I engage a qualified forensic pharmacologist in polydrug cases to dismantle the state’s combination-effect theory at the expert level.

Related pages: Florida DUI Defense Overview | DUI With Injury | DUI Charge Reductions in Polk County | Driver’s License Restoration | Boating Under the Influence