When most people think of an OUI, they picture someone driving under the influence of alcohol or illegal drugs. What many don’t realize is that in Massachusetts, and many other states, you can be charged with an OUI, even if the substance impairing your driving is a legally prescribed medication.
This may come as a surprise to responsible patients who are simply following medical advice. But the law focuses not on whether the drug is legal—but whether it impairs your ability to operate a motor vehicle safely.
Clear Definition of OUI
An OUI (Operating Under the Influence) is a criminal offense involving the operation of a motor vehicle while impaired by alcohol, illegal drugs, or any substance that affects your ability to drive safely. According to Massachusetts General Laws Chapter 90, Section 24, this includes legal prescription drugs.
The Commonwealth doesn’t need to prove that the drug was illegal—only that it impaired your ability to operate a vehicle. However, for a conviction of OUI-Drugs, the state must also prove that the drug you were under the influence of falls into one of the categories outlined in the statute: narcotics, stimulants, depressants, or marijuana.
How Prescription Drugs Can Lead to an OUI
Many common medications can impair your judgment, slow you reaction time, or cause drowsiness—all of which can make it unsafe to drive. These include:
- Benzodiazepines (e.g., Xanax, Valium, Ativan)
- Opioid painkillers (e.g., Oxycodone, Hydrocodone)
- Sleep aids (e.g., Ambien, Lunesta)
- Muscle relaxants (e.g., Soma, Flexeril)
- Certain antihistamines and anti-anxiety medications
Even with a valid prescription, if an officer observes signs of impairment, you can be arrested and charged with OUI-Drugs.
What Happens If You’re Pulled Over?
If you are pulled over and suspected of being under the influence of a prescription drug, you may be asked to perform field sobriety tests. In some cases, a Drug Recognition Expert (DRE) may be brought in to evaluate you. Unlike alcohol-related OUIs, which often involve breathalyzers, drug-related OUIs rely on officer observations, physical signs of impairment, and possibly blood or urine tests.
One of the challenges with prescription drug OUI cases is the absence of a clear “legal limit” like there is for alcohol. This means the case often centers on whether your behavior and driving indicate impairment.
Possible Defenses
While having a prescription doesn’t automatically protect you from an OUI charge, there are valid defenses, such as:
- You weren’t impaired – officer observations are subjective and may be contradicted by video evidence or witness testimony.
- Lack of notice – if the medication didn’t include clear warnings about driving impairment, you may have a defense.
- Procedural errors – if the officer lacked proper DRE training or did not follow correct protocols during testing, the case may be challenged.
How to Protect Yourself
Here are steps you can take to reduce your risk of being charged with OUI while taking prescription medications:
- Read all warning labels and follow them.
- Avoid driving when starting a new medication or changing dosages.
- Never mix medications with alcohol, which can intensify effects.
- Listen to your body. If you feel “off,” don’t get behind the wheel.
The Bottom Line
Yes, you can be charged—and convicted—of OUI-Drugs in Massachusetts even if you’re taking medication exactly as prescribed. The key factor is impairment, not legality. If you’ve been charged with OUI involving prescription medication, it’s crucial to contact an experienced criminal defense attorney as soon as possible. These cases are complex, often hinging on subjective observations and medical evidence. A knowledgeable defense lawyer can help you navigate the legal system and build a strong defense.
At Gilman Law, we specialize in defending individuals charged with OUI in Massachusetts—including cases involving prescription drugs.
