Prescription Drug DUI – Laws, and Defenses

Driving under the influence of a legal drug in Arizona is not solely a defense for DUI.

Last year, the Arizona Department of Public Safety revealed that prescription drugs were increasingly being found in the blood and urine tests of individuals who have been pulled over or arrested in Arizona and suspected of DUI. Prescription drug abuse is a common problem all over the United States, but Arizona had the sixth highest prescription drug abuse rate for 2010-2011 of all the states.

Because they are prescribed by a doctor, people often do not realize that misused or abused prescription drugs can be as dangerous as illegal recreational drugs like heroin or cocaine. It is important to be aware, however, that you can be charged in Arizona with driving or being in physical control of a vehicle while on certain prescription drugs, or while a “metabolite” of the drug is in your body. Recent Arizona case holds that it does not matter whether you are actually impaired by the drug.

Even if you appear to be driving safely, the State can prove your guilt simply by proving that any drug that is listed on the schedule of “dangerous drugs”, “narcotic drugs”, or “prescription-only drugs” were in your system. Under Arizona Revised Statute 28-1381, there is a narrow safe harbor defense to a “driving on prescription-only drug charge” under A.R.S.28-1381 D: This is the case, if you were using a drug as prescribed by a licensed medical practitioner, including doctors, dentists, podiatrists and osteopaths. That means you can use this defense if you took the amount that was prescribed by a physician, but you may not be able to use it if you took more.

In a prescription drug case last year, the appellate court was asked to explain just what was entailed by this defense. Several issues were in question: Does the burden of proof to show beyond a reasonable doubt that the prescription drug use was not justified–also called a justification defense? Or is it the responsibility of the person accused to mount an affirmative defense in which he must prove that he did not abuse prescription drugs, but used them according to a doctor’s directions? Or is the lack of a prescription or use of the drug against what a prescription says a key element of the crime? If it is a key element of the crime, it is something the State must prove in order to secure a guilty verdict.

The defendant was initially charged in municipal court for driving with Methadone, Klonopin and Ritalin (prescription-only drugs) in his body. The latter of these two are drugs that are commonly taken daily in order to treat psychiatric conditions like ADD and anxiety. Like illegal recreational drugs, however, these common prescription drugs can have powerful effects on one’s attention span, motor skills and focus. Klonopin is sometimes even taken to treat insomnia.

Fannin challenges the superior court’s holding that A.R.S. § 28-1381(D) creates an affirmative defense requiring him to prove by a preponderance of the evidence that he was using the drug as prescribed by a medical practitioner.

The municipal court ruled that the defendant had to make an initial showing that provided by a preponderance of the evidence that he was taking the drugs as prescrbed by a medical practitioner under the law. If successful, only then would the burden of proof shift to the State to show “beyond a reasonable doubt” that he was not. The State filed a special action petition with the superior court challenging the municipal court’s ruling. The superior court agreed with the State that the defendant was raising an affirmative defense, which attempts to excuse a defendant of the criminal action, for which they would otherwise be held accountable. By doing this, it places the burden of proof on the defendant.

The defendant appealed, asking the appellate court to answer the question of what kind of defense the safe harbor for prescription drugs was. The appellate court reasoned that the defense here was an exception to the general rule that it is a crime to drive with prescription-only drugs in one’s system. But the court established that A.R.S. 28 – 1381 (D) was in fact an Affirmative Defense. But the defendant failed to mount an Affirmative Defense. Relief was not granted on that basis.


Criminal law and defense can be a complex area in which fine distinctions are made. If you are arrested for driving with prescription drugs in your system, the entire burden of proof lies with you and your attorney. A knowledgeable criminal defense attorney may be able to poke holes in the State’s case against you. Contact the Law Offices of James Novak at (480) 413-1499 for help.

Additional resources

Drugs A-Z List

Prevent Prescription Drug Abuse (Attorney General)

Arizona Department of Public Safety

MORE BLOGS

Arizona’s Medical Marijuana Law Stands Ground, Arizona Criminal Defense Attorney Blog, June 4, 2013
Marijuana DUI: The Impact of Montgomery V. Harris in Arizona, Arizona Criminal Defense Attorney Blog, March 13, 2013

Contact Information