Yes, you can. In Texas as in other states, the law prohibits operating a motor vehicle while intoxicated by alcohol, drugs or a combination of substances. What many people don't realize is that you could be found guilty of DWI for driving under the influence of a legal drug that impairs your ability.
It's crucial to know how your prescriptions will affect you before getting behind the wheel. Drugs affect people differently, but many prescription drugs are known to impair concentration, alertness, judgment and motor skills in some people, and those impairments can be as serious as alcohol intoxication.
Common legal drugs that could impair your driving
Whether they are prescribed by a doctor or purchased over the counter, some drugs create a risk of driving impairment. Here are a few examples of common legal drugs and how they could affect you:
Antihistamines: These may make you drowsy, impair coordination and slow reaction time.
Decongestants: These may cause drowsiness and dizziness or anxiety.
Valium: Used as a tranquilizer or anti-anxiety drug, 10 milligrams of this benzodiazepine can cause impairment in some people that is equivalent to a blood alcohol concentration of 0.10 percent.
Sleeping pills: In rare cases, drugs like Ambien and Lunesta have caused people to sleep-drive. You may also find that you are still drowsy or experience other residual effects of the medication in the morning.
Antidepressants: Especially when people are unfamiliar with the effects or when they have recently increased the dosage, antidepressants can cause cognitive difficulties, indecisiveness, attention deficits, cognitive dysfunction and psychomotor impairment.
Opioids: Medicines containing hydrocodone, oxycodone, morphine, codeine or other opioid drugs such as Vicodin, OxyContin, Tramadol and Fentanyl are known to impair vision in some cases along with affecting cognitive and motor abilities, particularly when mixed with alcohol.
How do the police determine legal drug impairment?
For alcohol, the police have Breathalyzer and a per se DWI level of 0.08 percent to gauge your impairment. With legal drugs, it's not so straightforward.
Police can obtain a blood or urine test if they have probable cause to believe the driver is impaired, although a warrant may be required for blood tests. In many cases, however, the person using the prescription drugs admits to using them but denies being impaired. A blood test will confirm the presence of the prescription drugs, but it is unlikely to establish impairment.
In some situations, a drug recognition expert -- a police officer with special training -- may be called in to assess the driver for impairment. In most cases, however, whether you are arrested for DWI while using prescription drugs will depend almost entirely on the officer's judgment about whether you are impaired. A police officer's judgment could be sufficient evidence to convict you unless you defend yourself.