Law Offices of M. Gabriela Guraiib

Navigating the Grey Area: Can You Be Charged With a DUI for Your Prescribed Medication?


There’s no doubt that driving while intoxicated is dangerous. Decades of studies and collected crash report data demonstrate that consuming alcohol and other intoxicants before driving significantly increases the rate of crashes. That’s why every state, including California, has strict laws regarding drunk and intoxicated driving. 

While the laws surrounding alcohol use and driving are clear, there is more ambiguity around other substances. For example, you could be charged with a crime for driving after taking certain substances, even if you have a prescription. 

If you have a prescription for substances like cannabis, amphetamines, or any other controlled drug, you should be prepared for legal scrutiny. Here’s what you should know about DUI charges for prescription medications and possible defenses against these charges.

Defining DUI and DWI in California

Two terms often describe charges for operating a motor vehicle while impaired by a substance. The first is driving under the influence (DUI), and the second is driving while intoxicated (DWI).

In some states, these terms refer to different crimes. For example, DWI is often used for non-alcohol-related incidents, while DUIs are reserved for alcohol use. However, in California, the term DUI is used for all intoxicated driving charges.

There are several reasons why someone can be charged with a DUI:

  • They were driving while their blood alcohol content (BAC) was over 0.08%.
  • They violated traffic laws with a BAC greater than zero.
  • They were driving under the effect of an illegal or controlled substance without a prescription.
  • They were driving while impaired by any substance, including prescribed or over-the-counter (OTC) medications.

The last point is important. Under certain circumstances, you can be charged and convicted for driving while using your normal medications. However, before you can be convicted, it must be shown that the substance prevented you from being able to drive safely.

Understanding Prescription Medications and Their Effects

If over-the-counter and prescription drugs are considered safe and legal, why are they potentially grounds for DUIs? It’s because they can reduce your ability to drive safely. After all, alcohol and recreational cannabis are legal in California, but you may not drive under their influence, either.

Most OTC and prescription drugs do not pose a problem. Substances like cholesterol medications, antibiotics, and non-psychoactive drugs rarely impact your driving ability. However, any drug that affects your central nervous system can potentially make you dangerous behind the wheel. These include:

  • Opioid pain relievers
  • Anxiety medications that include benzodiazepines
  • Certain anti-seizure and antiepileptic drugs
  • Certain antidepressants
  • Antihistamines
  • Sleeping pills
  • Muscle relaxants
  • Diet pills and stimulants

In short, anything that can make you drowsy, dizzy, distracted, or slow your reaction time can make driving dangerous. Most of these medications warn you not to operate heavy machinery while under their effects, but not all. It’s crucial to understand how a drug affects your body before getting behind the wheel so you don’t put others at risk.

Assessing Impairment and Establishing Liability

The law enforcement officer may assess you for impairment if you’re stopped for a traffic violation. However, this is more difficult for prescription medications than any other substance. There is no alternative to the Breathalyzer test for other substances that can be used in the field.

Instead, the officer will likely have you perform one or more field sobriety tests. These tests measure your ability to follow instructions and complete physical tasks. The problem is that only three field sobriety tests have been certified by the National Highway Traffic Safety Administration (NHTSA):

  • Horizontal Gaze Nystagmus (HGN)
  • The Walk-and-Turn (WAT)
  • The One-Leg Stand (OLS)

Additionally, these tests only indicate someone’s impairment level when administered correctly and in the proper conditions. As such, it is not uncommon for officers to report that someone was impaired due to faulty testing. 

If field sobriety tests are not sufficient, officers must bring potentially impaired drivers to have a urine or blood test performed. These tests can chemically detect prescription drugs in the body. Still, they are not perfect, and there is room for error.

Legal Defenses and Protecting Your Rights

If you have been charged with a DUI for driving while using your prescription medications, you can fight back with the help of a skilled defense attorney. Possible defenses your lawyer may use include:

  • You were not impaired. Testing positive for a prescribed substance cannot be the sole grounds for a DUI conviction if you were driving safely.
  • The substance was prescribed. If you are charged with a DUI because you test positive for a controlled substance and no other reason, a prescription can be enough to drop the charges.  
  • The tests were faulty. If the arresting officer did not perform the field tests correctly, they should not be used as evidence that you were impaired.
  • Your rights were violated. If you were stopped and searched without due cause, your Fourth Amendment rights may have been violated, and the case could be thrown out entirely.
  • You were not warned about the side effects. If the medication label and pharmacist did not warn you about the risks of driving while taking a medication, your attorney may argue you could not know it was dangerous.
  • You have an unexpected reaction. If you have a rare and unexpected response to a medication, such as fainting, dizziness, mania, or seizures, you did not knowingly drive while intoxicated, and your DUI charge may be dismissed.

Talk to an Expert Defense Attorney About Your Prescription Medication DUI Charge

The best way to avoid a DUI charge for your prescribed medications is to drive safely and understand how your prescriptions influence your abilities. However, if you have already been charged with a DUI, you should speak to an experienced defense attorney about your case. The Law Offices of M. Gabriela Guraiib team is available to help you. Contact our Redwood City, California, defense law firm today to discuss your situation. We can help you fight the charges and prevent your normal prescriptions from giving you a permanent criminal record.