Driving and Drugs

Can I Be Charged for an OWI for Prescription Medication?

A person in the State of Iowa may be charged, and potentially convicted, of operating a motor vehicle while under the influence of a drug in addition to alcohol.  This includes prescription drugs as well as the better known illicit narcotics such as marijuana, cocaine, and other “street drugs.”

Iowa law prohibits an individual from operating a motor vehicle while “under the influence” of a drug, a combination of drug and alcohol, or with any amount of controlled substance present in their system. 

Prescription Medication OWI Defense

An affirmative defense to the “any amount” (legal limit) charge exists if the individual was taking the controlled substance/drug pursuant to a prescription and in accordance with the direction of the issuing doctor or pharmacist.  

Without Alcohol Consumption

If the person is charged with being “under the influence” of a drug, then the doctor or pharmacists prescription is only a defense if the individual was not instructed to refrain from operating a motor vehicle AND there I no evidence that alcohol had been consumed. 

With Alcohol Consumption

If there is evidence of alcohol being consumed then the charge turns into a combination of drug and alcohol offense which is treated the same as an ordinary operating while intoxicated charge.  An alcohol test result even below the legal limit can be used by the prosecution in an attempt to defeat a prescription defense to a driving while drugged case because it tends to show that some amount of alcohol had been consumed.  Consequently, admitting to officers “I was on prescription medication” is not helpful to a defense against a drunk driving charge if alcohol has also been consumed.

If the jury determines that the individual was legally “under the influence” of a combination of drug and alcohol, the individual can be convicted regardless of whether or not they had a valid prescription.  In these situations it is important not to make admissions to law enforcement that will negatively impact your case.  A knowledgeable attorney will also investigate the nature of this line of questioning by the officer in order to find ways to get any admissions suppressed or thrown out of court.


Have you been arrested or currently under investigation?

Contact Us

FREE Consultation

Local: 515-226-0500
Toll Free: 1-877-GRL-LAWS