Attorney
Yes, you can be arrested and charged with DWI in Texas after taking medication that was legally prescribed to you. Prosecutors must prove that the drug caused you to lose the normal use of your mental or physical faculties while operating a vehicle in a public place, but a valid prescription does not prevent them from pursuing the charge.
How Can Prescription Medication Lead to a Texas DWI?
Under Texas Penal Code Section 49.01, intoxication can result from alcohol, a controlled substance, a drug, a dangerous drug, or a combination of substances. The law does not distinguish between medication obtained legally and drugs taken without a prescription.
Certain medications can cause drowsiness, delayed reactions, confusion, blurred vision, or poor coordination. Common examples include opioid pain medication, anti-anxiety drugs, sleep aids, and some muscle relaxants. A driver may also experience stronger effects when a medication is combined with alcohol or another drug.
An officer may begin a DWI investigation after observing weaving, delayed braking, driving unusually slowly or speeding, or another perceived traffic violation. During the stop, the officer may look for physical or behavioral signs that suggest impairment.
How Do Police Investigate a Prescription Drug DWI?
A prescription drug investigation often differs from an alcohol-related DWI stop. A breath test cannot identify most medications, and Texas does not set a standard concentration at which a prescription drug automatically makes someone legally intoxicated.
Officers may instead rely on:
- Driving behavior and the reason for the traffic stop
- The driver’s speech, balance, movements, and responses
- Statements about medication use or medical conditions
- Prescription bottles or medication found in the vehicle
- Field sobriety test performance
- A blood test and toxicology report
In some cases, a drug recognition evaluator may examine the driver and identify a suspected drug category. The evaluator’s methods, observations, and alternative explanations for the reported symptoms can be challenged.
Can Field Sobriety Tests Prove Prescription Drug Impairment?
Field sobriety tests may be used as evidence, but poor performance does not necessarily prove intoxication. The standardized tests were developed primarily to help officers assess possible alcohol impairment. They cannot identify a drug or establish that a specific medication impaired the driver.
Medical conditions, injuries, fatigue, anxiety, footwear, and roadside conditions can affect performance. Body-camera or patrol-car video may show whether the officer gave proper instructions and whether the report matches what occurred.
What Does a Blood Test Show in a Drug-Related DWI Case?
After a DWI arrest, police may request a blood specimen. Texas law generally treats drivers as having consented to breath or blood testing following a qualifying arrest, but drivers may refuse in many circumstances. Refusal can carry license consequences, and officers may seek a warrant. These procedures are addressed in Chapter 724 of the Texas Transportation Code.
A toxicology report may identify a medication and estimate its concentration. Detection alone does not prove impairment at the time of driving. Drugs affect people differently, and some remain detectable after their effects have faded.
Does Having a Valid Prescription Help Your Defense?
A valid prescription can establish lawful possession, the prescribed dosage, and instructions for use. It may also provide context for when and why you took the medication.
A prescription does not resolve the DWI allegation. Prosecutors may claim that you drove despite known side effects, exceeded the prescribed dose, or combined the medication with another substance. We can examine pharmacy records, warning labels, medical documentation, and dosage timing to assess that claim.
What Are Common Defenses to a Prescription Drug DWI?
The available defenses depend on the arrest and testing records. Potential issues may include:
- No reliable evidence that the medication caused impairment
- Symptoms attributable to a medical condition or physical limitation
- Field sobriety tests administered or interpreted incorrectly
- A blood draw, search, or traffic stop that violated legal requirements
- Problems with the blood sample’s collection, storage, or testing
- Toxicology results that show drug presence but do not establish impairment
We may also challenge inconsistencies between police reports, video footage, witness accounts, and laboratory evidence.
Build Your Defense Before Evidence Is Lost
A prescription drug DWI charge can affect your license, employment, and record even if you took the medication as directed. Early review allows your attorney to preserve video, examine the blood-testing process, and obtain relevant medical records.
If you have been accused of driving while impaired by medication, contact Navarrete & Schwartz, P.C. We will evaluate the evidence, explain your options, and develop a defense based on the circumstances of your arrest.