Taking medication as prescribed does not necessarily prevent a DWI charge in Minnesota. Some prescription medications can cause impairment, meaning they can affect alertness, coordination, reaction time, or judgment. Minnesota’s driving while impaired (DWI) laws apply to drugs as well as alcohol, and certain controlled substances can create additional legal issues for drivers.
A lawful prescription may be relevant to a case, but it does not automatically prevent an arrest or charge. Understanding how Minnesota handles drug-related DWI offenses can help Lake Elmo drivers understand when prescription medication and driving may overlap.
How Prescription Medication Can Lead to a Minnesota DWI
Minnesota law provides different grounds for a DWI involving controlled substances, which are drugs regulated by law. Two are particularly important in prescription-medication cases:
- Driving while under the influence. A person can face a DWI charge when a controlled substance or its metabolite affects the person’s ability to operate a vehicle safely. A metabolite is a substance produced as the body processes a drug. A valid prescription does not authorize impaired driving.
- Driving with certain controlled substances present. Minnesota law also generally prohibits driving when a person’s body contains any amount of a Schedule I or Schedule II controlled substance or its metabolite, subject to statutory exceptions and defenses.
Schedule I and Schedule II are legal classifications for controlled substances. Schedule I generally includes substances classified as having no currently accepted medical use, while Schedule II includes substances that may have accepted medical uses but are subject to strict controls. Some prescription medications, including certain opioid pain relievers, are classified as Schedule II.
Detection and impairment are not necessarily the same. Detection means testing can identify a drug or metabolite in the body, while impairment means the drug affects the person’s ability to drive safely. Depending on the drug, it may remain detectable after some of its effects have diminished.
How Is Prescription Drug Impairment Evaluated?
Prescription-drug cases do not have one numerical impairment threshold that applies to every medication. The evidence instead depends on the legal basis for the charge and the circumstances of the investigation.
Law enforcement may consider driving behavior, statements, physical observations, and performance on field sobriety tests, which are roadside exercises used to observe possible signs of impairment. Blood or urine testing may also be used to identify drugs or their metabolites.
A positive chemical test can identify the presence of a substance, while observations from the stop may bear on whether the medication affected the person’s ability to drive. A lawyer can review the reason for the stop, the officer’s observations, testing procedures, the substance identified, and other evidence relevant to the charge.
When Can a Valid Prescription Provide a Defense?
Minnesota law provides an affirmative defense to the offense based on the presence of a Schedule I or Schedule II controlled substance when the defendant proves the substance was used according to a prescription issued for that person. An affirmative defense is one the defendant has the responsibility to establish rather than an element the prosecutor must prove.
The defendant must establish this defense by a preponderance of the evidence, meaning it is more likely than not that the medication was used according to the prescription. Prescription records and other evidence about how the medication was used may therefore be important.
A prescription does not permit impaired driving. If the allegation is that the medication actually impaired the person’s ability to operate the vehicle, having a valid prescription does not by itself resolve that issue.
Prescription Medication and Implied Consent
Prescription use can also be relevant in Minnesota’s implied consent process, the legal framework governing chemical testing and certain driver’s license consequences for suspected impaired driving. Minnesota law provides a prescription-use affirmative defense during judicial review, a court proceeding in which a judge reviews the license action. However, that defense does not apply if the court finds by a preponderance of the evidence that the prescribed substance impaired the person’s ability to drive.
The criminal DWI case and driver’s license proceeding therefore should not be treated as interchangeable. The issues can depend on the substance involved, how it was used, and the evidence of impairment.
Reviewing a Prescription Drug DWI in Lake Elmo
A prescription-drug DWI can involve several questions. An attorney may need to review:
- Why the traffic stop occurred and what the officer observed.
- What medication or controlled substance testing identified.
- Whether the medication was used according to a valid prescription.
- Whether there is evidence that the medication impaired driving.
- How field sobriety and chemical testing were conducted.
- Whether separate driver’s license proceedings or deadlines apply.
A driver taking prescribed medication in Lake Elmo, Woodbury, or elsewhere in Washington County may face questions about both the presence of the medication and its effect on driving. Identifying the legal basis for the charge can help determine which evidence and defenses may be relevant.
Coodin Law Office, LLC is a Minnesota law office that represents people facing DWI and other criminal charges. If you have been charged with a prescription-drug DWI or have questions about related driver’s license consequences, contact our law office to discuss your circumstances with an attorney.