Can I Be Charged with DUI in Washington for Prescription Drugs?

When most people hear “DUI,” they think of alcohol or illegal drugs. But in Washington, the law takes a much broader view. You can be charged with driving under the influence even if the substance in your system was legally prescribed by your doctor. If that medication affects your ability to drive safely, it can still lead to criminal charges and you can Charged with DUI for Prescription Drug — and have serious consequences.

Driving Impaired Is the Core Issue — Not Just What You Took

Washington’s DUI statute doesn’t just cover alcohol. Under RCW 46.61.502, a person can be found guilty of DUI if they drive while under the influence of, or affected by, any intoxicating liquor, cannabis, or drug. That includes legally prescribed medications — even those taken exactly as directed.

What matters under the law isn’t whether the substance was legal or illegal. What matters is whether it impaired your ability to drive with the same caution and control as a sober person under similar circumstances.

Common Prescriptions That Can Lead to a DUI Charge

Many medications come with warnings about drowsiness, slowed reaction times, or dizziness. Even though these effects are well-known, people often assume that following the dosage instructions will shield them from criminal charges. Unfortunately, that’s not the case.

Prescription medications such as opioids, anti-anxiety medications like benzodiazepines, sleep aids, and even certain antidepressants can all impair your ability to drive. Even over-the-counter medications, such as antihistamines or nighttime cold remedies, can lead to DUI charges if they affect your coordination, focus, or alertness behind the wheel.

The short answer is no. While it’s important to show that you were taking your medication legally, a valid prescription does not protect you from a DUI charge in Washington. The court’s concern is whether your driving was impaired — not whether you were authorized to take the drug.

This can come as a shock to many people, especially first-time offenders or those managing chronic medical conditions. You may believe you were acting responsibly, but the law can still treat you as if you were driving under the influence of an illegal substance.

How Officers Detect Prescription Drug Impairment

Unlike alcohol, there is no simple breathalyzer test to detect most prescription medications. Instead, law enforcement often relies on a combination of field sobriety tests, behavioral observations, and, in some cases, evaluations by specially trained officers known as Drug Recognition Experts (DREs). Blood tests may be ordered to confirm the presence of a substance, but unlike alcohol or cannabis, there are no clear numerical thresholds for most medications. That means impairment is often a subjective judgment — and that opens the door for legal challenge.

A DUI involving prescription drugs can be legally complex and fact-specific. You may have been following your doctor’s instructions carefully and still find yourself facing a serious criminal charge. These cases require close attention to the facts, including your dosage, how the medication affects you individually, and whether law enforcement followed proper procedures during the investigation.

At the Law Office of Erin Bradley McAleer, we understand how frustrating and confusing this process can be. We regularly represent clients who are shocked to find themselves charged after doing what they believed was completely legal. Our job is to challenge those assumptions and build a strong defense based on the actual facts — not assumptions or shortcuts.

Facing a DUI Charge in Washington? Call Us Today.

If you’ve been charged with DUI in Clark County or Southwest Washington, and prescription drugs are involved, don’t wait to seek legal advice. The earlier you act, the more options we can preserve. Call the Law Office of Erin Bradley McAleer today for a free consultation and let us help you protect your record, your license, and your future.