Many Texans take prescribed medications every day, but few realize they can still face criminal charges for impaired driving. In Texas, you can be arrested and charged with DWI even if the substance affecting you is completely legal and prescribed by your doctor. For official definitions, see the Texas Penal Code §49.01 and the National Highway Traffic Safety Administration guidance on drug-impaired driving.
At The Law Office of Robert M. Maurer II & Associates, we’ve spent more than 30 years defending drivers across South Texas. Born and raised here, educated locally, and deeply connected to our communities, we speak Spanish, know our clients personally, and provide 24-hour support to anyone facing these challenging charges.
Texas Law: Impairment Matters, Not Whether the Drug Is Legal
Texas DWI law does not require alcohol. Instead, the question is simple:
Were you impaired in a way that affected your ability to operate a vehicle safely?
This means prescription medications—such as painkillers, muscle relaxants, anti-anxiety drugs, sleep aids, ADHD medication, and antidepressants—can all lead to a DWI if they affect:
- Reaction time
- Coordination
- Concentration
- Judgment
- Vision
- Alertness
Even when taken exactly as prescribed, some medications warn against driving or operating heavy machinery. If an officer believes your driving was impaired, you may be arrested and charged.
This is why drivers often seek a DWI attorney as soon as they are accused.
How Police Determine Prescription-Related Impairment
During a traffic stop, police rely heavily on observations. This may include:
- Slurred speech
- Confusion or disorientation
- Bloodshot or droopy eyes
- Difficulty handling paperwork
- Erratic driving
- Unsteady balance during field sobriety tests
Because many medications have side effects unrelated to intoxication, officers frequently misinterpret symptoms. Texas officers may call in a Drug Recognition Expert (DRE), but even those evaluations are subjective and can be challenged.
Additionally, blood tests do not always show impairment—only that a substance is present. Presence is not proof of intoxication.
This distinction is often the strongest defense for clients represented by a criminal defense lawyer.
Common Prescription Medications That Lead to DWI Charges
Several types of medications frequently appear in DWI cases, including:
- Benzodiazepines (Xanax, Valium)
- Opioid pain medications (hydrocodone, oxycodone)
- Sleep medications (Ambien)
- Muscle relaxants
- Certain antidepressants
- Antihistamines and cold medicines
These drugs can cause drowsiness or delayed reaction times even when taken in recommended doses.
Defenses Available in Prescription Medication DWI Cases
At The Law Office of Robert M. Maurer II & Associates, we examine every detail to build a strong defense. Key defense strategies may include:
1. Challenging Field Sobriety Tests
These tests are designed for alcohol impairment—and are often unreliable for prescription drug cases.
2. Questioning Blood Test Interpretation
Levels in blood do not necessarily correlate with impairment. We often use medical experts to challenge scientific assumptions.
3. Lack of Probable Cause for Arrest
If the officer misinterpreted medication side effects, the arrest may be unsupported.
4. Showing Lawful Prescription Use
Taking a medication as prescribed can be a powerful part of the defense narrative.
5. Highlighting Medical Conditions
Fatigue, anxiety, or medical issues can mimic signs officers consider “impairment.”
We’ve tried cases across South Texas for more than three decades, giving us unique insight into how local courts view drug-based DWI charges. That local experience matters.
Why Should You Hire The Law Office of Robert M. Maurer II & Associates?
Legal problems can be overwhelming, but you don’t have to face them alone. At the Law Office of Robert M. Maurer II & Associates, our experienced team defends Texans in drug-related DWI cases—whether you need a San Antonio drug defense lawyer, defense attorney, or a criminal defense attorney. Explore our practice areas or learn how we can help. For immediate help, call now—we’re available 24/7 with strong South Texas ties and personalized support.
