Most Carbon County resident equate alcohol with driving under the influence of an intoxicant incidents. But prescribed or over-the-counter medications can impair a driver and lead to a DUI arrest, points out the Utah Highway Patrol. Prescription drugs like Valium, anti-depressants and pain killers can cause drowsiness, and impair motor skills. If taken with a alcohol, the adverse effects can increase. Prescriptions usually have warning labels advising to people to exercise caution while driving or operating heavy machinery after taking the medications. The UHP encourages residents to ask physicians or pharmacists about a medication's side effects and avoid driving under the influence.