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.