Looking at the wording of the state statute, it's clear that the charge of DWI was never meant to apply solely to drinking. If you are mentally impaired for any reason, you shouldn't be driving. Period. It's that simple, and passing a breath test for alcohol will not get you off the hook. Even if the drug in question is legal and was prescribed to you by a licensed physician, there is nothing in the law that will excuse you for driving while your judgment is impaired.

To keep from getting a Texas DWI charge unwittingly, make sure to read the labels on every drug you take, even if it's something over-the-counter. If the side effects mentioned include dizziness or drowsiness, you should not drive until you know how the drug will affect you.