DUI & Criminal Defense

2501 North 7th Street
Phoenix, AZ 85006

Prescription Drug DUI | Medication DUI | Arizona

Prescription Drug DUI | Medication DUI

The Ultimate Guide

Prescription Drug DUI Arizona

A Prescription Drug DUI in Arizona results from driving with a drug in your system while, either:

(1) being impaired

(2) without a prescription

(3) not using as precribed

“But I had a prescription!”

Obviously it’s illegal to drive impaired by oxycotine…even if you have a prescription. The same is true with marijuana or any other drug.  However, how would the police determine if you were impaired by a prescription drug?

No Universal Level of Impairment

It is generally accepted in the scientific community, that at an alcohol concentration of .08, just about everyone is impaired for the task of driving. However, the same is not true for drugs. Neuropharmacology has shown significant differences in the way alcohol and other drugs affect the body.

There is no such correlation for the amount of a drug in your blood (or urine) and impairment. The result of a chemical test is simply not capable of proving impairment.

“CAVEAT INTERPRETOR! As man does not live only by bread, so the toxicologist cannot interpret his results by numbers alone...”

Dr. Irving Sunshine, World-Renown Toxicologist Tweet

But What About the Therapeutic Range?

Blood Levels Drug DUI

The government often argues that a therapeutic level is evidence of drug impairment. They do this by reference to a drug’s therapeutic level.

A drug’s therapeutic level refers to either: (1) The dosage range or (1) Blood plasma / serum concentration usually expected to achieve desired therapeutic effects.

In more basic terms, the purpose of most psychiatric medications is get the person to her “normal” state of being.  That is a valid and desired medical purpose.

Panic Attacks

Think about the person who suffers from panic attacks.  Is it safer for that person to drive properly medicated (and unimpaired) with their medication or without?  I would prefer properly medicated.

When medication is achieving it’s desired result we know the person has the proper amount. At this point, the level of the drug in a person’s system is the therapeutic level. This level for any particular drug will vary from person to person. Contrary to how it is often presented by the prosecution, it is not evidence of impairment.

"As Prescribed"

If you took Valium the day before drove to work then the effects have long subsided.  While driving to work the next you no longer impaired by this drug. Keep in mind, the reason you were prescribed the medication was an anxiety condition.  So when the officer stopped you for speeding it was predictable that your condition was triggered by traffic stop by law enforcement.  The symptoms you’re exhibiting could easily be mistaken for impairment. If you medical provider prescribes


  • What facts show drug abuse or not taken as prescribed?
  • How would you know know if the medication was not taken as prescribed?
  • What records did the police seek? or not?
  • Is it a drug that requires a prescription? 
  • Was a refill required if the prescription was written a long time before consumption? 
  • If you went doctor shopping wouldn’t there be a record?

Now that the officer arrested you for DUI, mistakenly believing your were impaired by the medication, you have a defense. Assuming you can prove that the symptoms impairmement were not caused by a drug – then you have a legal defense that you had a valid prescription. Put another way, the law states it’s a defense to the allegation that there was a controlled substance in your system, if you have a valid precription.  

Prescription Drug DUI | ARIZONA

Frequently Asked Questions

How does Arizona define a prescription drug in a DUI case?

We all understand that “prescription” drugs are the medications your doctor have determined you need to treat some medical condition and have given you permission you to use. This is commonly done by giving you a written prescription or by a direct call from the medical provider to your pharmacy. However, in the case of driving under the influence laws, Arizona has given some additional legal meaning what we commonly consider as prescription drugs.

ARS 13-3401(28) provides that a “Prescription-only drug” does not include a dangerous drug or narcotic drug but means:

(a) Any drug which because of its toxicity or other potentiality for harmful effect, or the method of its use, or the collateral measures necessary to its use, is not generally recognized among experts, qualified by scientific training and experience to evaluate its safety and efficacy, as safe for use except by or under the supervision of a medical practitioner.

(b) Any drug that is limited by an approved new drug application under the federal act or section 32-1962 to use under the supervision of a medical practitioner.

(c) Every potentially harmful drug, the labeling of which does not bear or contain full and adequate directions for use by the consumer.

(d) Any drug required by the federal act to bear on its label the legend “

Another way to think about this is, a drug will fall within this legal definition if, the medical community has recognized it is safe when taken as prescribed by a doctor.


Yes.  Consider the person who was legally given morphine at a hospital for an injury.  They then drive home from the hospital while still impaired by the medication.  This is a textbook example of a case that started with legal drug use and then turned into a DUI.

No.  In the case of a DUI based upon the consumption of alcohol, Arizona has “per se” laws.  For example, it is illegal for a person to drive with an alcohol concentration of .08 (the makes a presumption that a person is impaired at this level).   This is not the case when it comes to a prescription drug DUI allegation.

This actually makes a lot of sense as, unlike alcohol, there is no universal level of impairment when it comes to drugs.  The way prescription drugs affect the human body is very different than alcohol.  Simply put, when it comes to prescription medications, there is no numerical definition of chemical impairment.

Driving with a prohibited drug in your system, in and of itself, is a violation of Arizona’s DUI laws.  This is technically true even if you are not impaired by the drug. 

Receiving two charges for prescription medication DUI is standard practice.

One charge alleges you were impaired while driving. The other charge claims you have a drug in your system that was either illegal or you did not have valid prescription for its use.

Receiving these two charges does not mean your case was worse than other Arizona prescription cases.  

A first offense DUI based upon prescription drug is a Class 1 misdemeanor and the penalties are the same as an alcohol DUI. 

Yes, but these cases should not be charged by the government.  Drugs like Ambien sometimes have unintended consequences that were not the result of a voluntary act.

You can get a DUI on Xanax. Xanax is common medication found in driving while under the influence of drugs cases.

Ready to fix this?
(602) 494-3444

Can you get a DUI for prescription medication?



2501 N. 7th Street | Phoenix AZ 85006 | (602) 494-3444