All drivers know that it is illegal to operate a motor vehicle while drunk. When it comes to prescription medications, many drivers question whether they are permitted to get behind the wheel. After all, medication prescribed by a doctor serves an important medical purpose and is not taken for recreation. Iowa has very specific rules about driving while on prescription medication, and all drivers should be aware of these laws so they remain in compliance. 

Zero tolerance rules about driving while medicated 

Drivers are only in violation of DUI laws when their blood alcohol content (BAC) exceeds .08%. With drugs, Iowa takes a zero-tolerance stance; any amount of any controlled substance or drug is considered a punishable offense. In order for law enforcement to prove a person was operating a vehicle while intoxicated, it must be shown the person was indeed operating the vehicle at the time and that the person was under the influence of drugs or the presence of drugs were found in a person’s blood or urine. 

Defense against OWI charges 

If a person is charged with an OWI as a result of driving while on prescription medication, there are possible defenses that can be used on their behalf. Using medication in accordance with a doctor or other medical professional’s instructions can be used as a defense if a person is found to have the presence of a drug after chemical testing. However, if the person also tests positive for alcohol, this defense will not hold. Also, this defense will not be applicable if the person was told by a doctor or pharmacist not to take the medication and operate a motor vehicle. 

Implied consent laws 

Regardless of the defense used, all drivers are beholden to implied consent laws when operating a motor vehicle. These laws stipulate that drivers must submit to chemical testing if requested by an officer who has a reasonable suspicion of intoxication. When drivers refuse chemical testing for the first time, they are subject to a mandatory 90-day revocation of their licenses, although revocation can last as long as a year. Second and subsequent refusals incur even harsher penalties.