Most people associate DWIs with alcohol, but prescription drugs can also lead to charges. Many medications impact coordination, reaction time, and judgment, making it unsafe to drive. If law enforcement believes a driver is impaired, a DWI charge can follow—even if the drug is legally prescribed.
How prescription drugs cause impairment
Certain medications affect the central nervous system, leading to drowsiness, dizziness, or confusion. Opioids, muscle relaxers, and sleep aids can slow reaction times. Anxiety and depression medications may cause drowsiness or blurred vision. Even over-the-counter drugs like antihistamines can impact driving ability.
Missouri’s DWI laws and prescription drugs
Missouri law prohibits driving under the influence of any substance that impairs driving ability. A blood test can detect prescription drugs, and officers can arrest someone if they show signs of impairment. Unlike alcohol-related DWIs, there is no legal limit for prescription drugs, so charges depend on observed behavior and test results.
Defenses against prescription drug DWIs
A valid prescription does not protect against a DWI charge, but defenses exist. If the driver took the medication as directed and was not impaired, they may challenge the charge. Officers must prove impairment, not just the presence of medication. Improper testing or an unrelated medical condition could also serve as a defense.
Avoiding a prescription drug DWI
Drivers should read medication labels and follow warnings about drowsiness or dizziness. Combining medications or using them with alcohol can increase impairment risks. If a new prescription causes side effects, driving should be avoided until its effects are known. Speaking with a doctor about alternatives or dosage adjustments may help prevent impairment.
Prescription medications can affect driving ability, and Missouri law does not differentiate between legal and illegal substances when it comes to impairment. Understanding medication effects and driving responsibly can help avoid legal trouble.