LAS VEGAS (KSNV) — Impaired driving is no longer just about alcohol, as law enforcement and prosecutors across the country report a sharp rise in DUI cases tied to cannabis, prescription medications, and even driver fatigue.

Many motorists are surprised to learn they can be charged without ever taking a drink.

Rory Safir, a forensic lawyer scientist and founder of Safir Law, spoke with News 3 about these concerns.

He says in most states, impairment statutes cover any substance that affects normal faculties, including legal cannabis and common prescription drugs.

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Unlike alcohol-related cases, there is often no clear numerical threshold for impairment in these situations. Instead, cases frequently rely on officer observations, field sobriety tests and the interpretation of toxicology results.

Prescription medications such as sleep aids, anti-anxiety drugs and certain pain medications can be legally used but still form the basis of a DUI charge if they impair a person’s ability to drive.

Fatigue and combined impairment — such as mixing small amounts of alcohol with medication — can also create legal exposure even when someone feels subjectively fine to drive.

Because these cases can be more subjective, they often hinge on the quality of the investigation and the scientific interpretation of toxicology findings.

Simple preventative steps can help reduce risk, including reading medication warnings, allowing adequate time before driving and arranging alternative transportation.