Most drivers in Montana understand that taking certain drugs, such as cocaine, is illegal. However, not everyone realizes that taking prescription drugs and even over-the-counter medication can be illegal. While taking them normally is not an issue, it can become problematic if taken before getting behind the wheel. Certain medications have side effects that interfere with driving ability, and this can lead to a DUI. 

The FDA reports that while not all medication inhibits driving, there are certain types that do. These include: 

  • Anxiety medication 
  • Pain medication 
  • Antidepressants 
  • Allergy and cold remedies 
  • Stimulant (ephedrine, caffeine) drugs 
  • Tranquilizers and sleeping pills 

Taking these drugs before driving can result in a DUI because some of their reactions, including difficulty focusing, impaired vision, dizziness, slowed reaction time, drowsiness and fainting. 

According to the National Institute on Drug Abuse, marijuana, even for drivers who have their medical license, can also become a legal problem if one drives under its influence. Research shows that its effect on driving includes a lack of attention, lane weaving and slowed movements and reaction time. The effects of drugs and medication increase when taken in conjunction with alcohol. 

The use of drugs contributes to over 40% of fatal crashes, but it is difficult to know how many accidents in general are due to drug use. There are numerous reasons for this. One is there is not a roadside test to test for drug levels like there is for alcohol. Some drugs also take a while to leave the system, making it hard to establish their contribution in a crash. Many people also have the presence of alcohol or multiple drugs, making it difficult to determine which substance is at fault.