Setareh Law
March 11, 2026
Most people associate impaired driving with alcohol or illegal drugs, but millions of Americans take prescription medications every day that carry warnings about drowsiness, dizziness, blurred vision, and slowed reaction time, all of which can make operating a vehicle just as dangerous. When a driver causes an accident while under the influence of a legally prescribed medication, the legal question of liability is more nuanced than many victims realize, and understanding it can be the difference between full compensation and an uphill battle.
If you were hurt by a driver impaired by prescription medication, you deserve answers and strong legal representation. Setareh Law has recovered over $250 million for injured Californians and brings 60+ years of combined experience to every personal injury case we handle. Our attorneys understand how impairment from any source, including prescription drug impairment, affects liability and how to build a compelling case on your behalf.
The Scope of Drug-Impaired Driving in California
Prescription medication impairment is a growing traffic safety concern that often goes underdiscussed. According to UC Berkeley’s Safe Transportation Research and Education Center, there were 751 people killed in drug-involved traffic crashes in California in 2021 alone, and drugs can affect driving skills by slowing reaction time, decreasing coordination, increasing aggressive driving, impairing cognitive function, and causing drowsiness.
These are precisely the side effects listed on the warning labels of countless common prescription medications, including opioids, benzodiazepines, antihistamines, sleep aids, muscle relaxants, and certain antidepressants. The fact that a drug is legally prescribed does not make its effects on driving ability any less dangerous.
How California Law Treats Prescription Drug Impairment
California law does not distinguish between legal and illegal substances when it comes to impaired driving. Under California Vehicle Code Section 23152, it is unlawful for any person to drive a vehicle while under the influence of any drug, including a legally prescribed one, if that drug impairs their ability to drive with the ordinary care and caution of a sober person. This means a driver who causes an accident while impaired by their prescribed medication can face criminal DUI charges and, separately, civil liability for all damages they caused. The prescription itself is not a defense.
What “Impairment” Means Under Civil Law
In a personal injury claim, the standard for proving impairment is distinct from the criminal DUI threshold. A victim does not need to show the driver was criminally intoxicated to establish civil liability. They need to show the driver failed to exercise reasonable care while operating a vehicle, and that the medication’s effects on the driver’s judgment, reaction time, coordination, or alertness contributed to that failure. Medical records, prescription labels, toxicology reports, and police reports documenting the driver’s behavior at the scene can all serve as powerful evidence in a civil case.
Common Prescription Medications That Impair Driving
Many widely prescribed drug classes carry explicit warnings against operating heavy machinery or driving. Opioid painkillers such as oxycodone and hydrocodone are among the most well-documented driving hazards, causing sedation and slowed reflexes even at therapeutic doses. Benzodiazepines prescribed for anxiety and sleep disorders, such as Xanax and Valium, similarly depress the central nervous system. Sleep aids, including zolpidem, are notorious for residual impairment that extends well into the following morning. Even some antihistamines, blood pressure medications, and muscle relaxants carry impairment warnings. A driver who gets behind the wheel knowing their medication causes these effects, or who ignores their doctor’s or pharmacist’s explicit driving warning, has made a choice that exposes them to significant civil liability.
Building the Evidence Chain
Establishing that a driver was impaired by prescription medication at the time of the crash requires careful investigation. The following types of evidence are typically pursued in these cases:
- Toxicology results: blood or urine tests conducted after the accident can identify the presence and concentration of specific prescription drugs
- Prescription records: evidence that the driver was prescribed a known impairing medication close in time to the accident
- Pharmacy and warning documentation: records showing the driver was informed of the medication’s effect on driving
- Medical records and expert testimony: a medical expert can explain how the specific drug at the likely concentration in the driver’s system would have impaired their ability to drive safely
- Police and accident reports: officer observations of the driver’s appearance, behavior, and statements at the scene can corroborate impairment
This type of evidence-building requires experience and resources that a skilled personal injury attorney brings to the table.
How This Affects Your Personal Injury Claim
When a distracted or impaired driver causes a crash due to prescription medication side effects, the full spectrum of damages remains available to the injured victim. Medical expenses, lost wages, future care costs, and pain and suffering are all recoverable in a California personal injury claim.
In cases involving severe physical trauma such as brain injuries, the financial and personal toll can be devastating and long-lasting. When an accident results in a fatality, surviving family members may pursue a wrongful death claim against the impaired driver and potentially against other parties such as a prescribing physician who failed to counsel the patient about driving risks. California’s pure comparative fault system means your recovery may be adjusted if any portion of fault is attributed to you, but even partial fault does not eliminate your right to compensation.
Contact Setareh Law After a Crash Involving an Impaired Driver
Crashes caused by prescription drug impairment require skilled investigation, medical knowledge, and tenacious legal advocacy to prove, and Setareh Law has the experience to handle every element of that process. We take all cases on a contingency fee basis, meaning you pay nothing unless we win. We serve clients across eight California office locations, offer bilingual services, and have earned over 400 five-star Google reviews from clients who trusted us with their most serious cases.
To learn more about our attorneys and track record, visit our firm profile, or contact us today for a free consultation. Setareh Law is ready to investigate your case, identify every liable party, and fight to recover the full compensation you deserve.
