Seattle Drug-Related DUI Law

Driving under the influence in Washington is not limited to alcohol. You can be arrested and charged with DUI for driving under the influence of marijuana, illegal drugs, or even prescription medications.

If you have been arrested for a drug-related DUI in Seattle, you are facing serious penalties — including jail time, license suspension, and substantial fines.

Washington Drug DUI Law (RCW 46.61.502)

Under RCW 46.61.502, a person is guilty of DUI if they drive a vehicle within the state and:

  • Have a THC concentration of 5.00 nanograms per milliliter of whole blood within two hours of driving, OR
  • Are under the influence of or affected by any drug, including prescription medication.

Unlike alcohol cases, most drug DUIs do not rely on a defined numerical limit. With the exception of marijuana, prosecutors often proceed under an “affected by” theory — meaning the State argues you were impaired regardless of the amount in your system.

Types of Drug DUI Charges

Drug-related DUI charges may involve:

  • Marijuana (THC)
  • Cocaine
  • Methamphetamine
  • Opioids
  • Benzodiazepines
  • Prescription sleep aids or pain medication
  • Combination of drugs and alcohol

You can be charged even if the medication was legally prescribed.

How Drug DUI Arrests Happen

When officers suspect drug impairment, they may:

  • Conduct field sobriety tests
  • Request a Drug Recognition Expert (DRE) evaluation
  • Request a blood test

Unlike breath tests used in alcohol cases, drug DUIs usually require a blood draw. The accuracy of blood testing, chain of custody procedures, and timing of the test are critical issues in these cases.

Penalties for Drug DUI in Washington

The penalties for a drug-related DUI are the same as those for alcohol DUI under RCW 46.61.5055. Depending on your prior history, penalties may include:

  • Mandatory jail time
  • Fines up to $5,000
  • License suspension or revocation
  • Ignition interlock device requirement
  • Drug or alcohol evaluation and treatment
  • Probation supervision

You also have only 20 days from the date of arrest to request a Department of Licensing hearing to challenge your license suspension.

Defending a Drug DUI in Seattle

Drug DUI cases are often more complex than alcohol cases. Defense strategies may include:

  • Challenging the traffic stop
  • Questioning DRE evaluation methods
  • Attacking blood testing procedures
  • Examining whether the drug level actually caused impairment
  • Identifying constitutional violations

Because most drug DUIs rely heavily on officer observations and subjective assessments, these cases frequently present opportunities to challenge the State's evidence.

Call a Seattle Drug DUI Defense Lawyer

Being charged with a drug-related DUI does not mean you will be convicted. Early legal intervention can significantly affect the outcome of your case.

Call 206-222-3280 now for a free consultation. Available 24/7.