Controlled Substance DWI

It’s common for people to associate driving while intoxicated (DWI) solely with alcohol. Texas law would, however, disagree with you. You could be charged with DWI for driving impaired on a controlled substance since the effects are similar to inebriation. A controlled substance can still lead to a high blood-alcohol concentration (BAC) like alcohol. The majority of controlled substances inhibit your motor controls and can affect your driving. Even driving after taking some prescription drugs can lead to a DWI. If you or someone you know has been charged with DWI involving drugs, it’s imperatnive you contact an experienced criminal defense attorney.

Attorney for Drug DWI in Houston, Texas

In 2016, the Center for Disease Control and Prevention (CDC) reported 16 percent of all motor vehicle crashes involved drug-use. Texas has decided to combat this with stringent DWI laws. If you or someone you know has been charged with DWI, it’s crucial you seek legal representation. The attorneys at Tyler Flood & Associates, Inc. have handled numerous DWI cases in Texas.

They’re passionate about criminal defense and will use their knowledge in DWI law to assist you. Call Tyler Flood & Associates, Inc. today at (713) 224-5529 to schedule a case consultation. Tyler Flood & Associates, Inc. represents clients throughout the greater Houston area including River Oaks, Uptown, Pasadena and West University Place. Overview of Drug Impaired DWI in Texas

Are Drugs Included in DWI Laws in Texas?

Driving while intoxicated (DWI) is a serious charge under Texas law. Many believe it only incorporates alcoholic beverages, but the truth is you could be charged for driving under the influence of drugs as well. The Texas Penal Code § 49.04 states you’re committing DWI if you:

  • Drive a motor vehicle on public roads; and
  • Your blood-alcohol concentration (BAC) is at or above .08 OR your physical and mental faculties are impaired by alcohol or a controlled substance

It’s much easier to detect a person is inebriated from alcohol. Law enforcement use chemical tests to measure BAC and field sobriety tests to assess your physical and mental faculties. With drugs, it can get a little more complicated.

Back to top

DWI Drug Testing in Houston, Texas

Police officers will often default to urine or blood analysis if they suspect drug-impaired driving. Urinalysis will identify drugs through a urine sample. However, the process is by no means perfect. Urine test results often bring up substances you used days or weeks ago because they’re still in your system. For example, you could have marijuana in your system for up to two weeks even if you’re not a heavy user. The metabolites and other chemicals will still remain in your body days or even weeks after you consumed the drug. You could be charged with DWI because the drugs you used days ago appeared on you results. A blood draw is the most accurate test when it comes to drug use. Even then, it still has problems. Lab technicians could make human errors which could lead to a false positive. In some cases, the equipment used at the crime lab is outdated and your results can come back incorrect. A common question for attorney is if you should submit to DWI testing. Most attorneys would answer no, you shouldn’t comply with DWI testing. Law enforcement can detect drugs in your system through urine or blood analysis. Additionally, submitting to chemical testing will increase your chances of reducing or dismissing your charges. The prosecution heavily relies on DWI testing results to make a conviction. A refusal will make their job difficult because they will have to rely on circumstantial and objective evidence. Because of this, it’s highly advised you refuse DWI testing.

Back to top

Penalties for DWI in Harris County, Texas

Drug-impaired driving has the same legal consequences as an alcohol-related DWI. The penalties will depend on if you have prior DWI convictions or the circumstances of the DWI. The chart below lists the maximum statutory penalties for DWI.

Number of Offenses: Offense Level: Jail/Prison Time: Fine:

First Offense

Class B Misdemeanor Minimum of 72 hours in jail; maximum of 180 days in jail


Second Offense

Class A Misdemeanor

Minimum of 30 days in jail; maximum of 12 months in jail


Third Offense Third-Degree Felony Minimum of 2 years in prison; maximum of 10 years in prison


A judge could add conditions to your sentencing if you are convicted of DWI. You must complete these conditions as a part of your legal punishment. Some of these conditions include:

  • License suspension;
  • Required community service;
  • Installation of an ignition interlock device (IID);
  • Drug and alcohol evaluation;
  • Community supervision;
  • Completion of a DWI Education Program;
  • Annual fee by the Texas Department of Public Safety (DPS) of up to $2,000 for 3 years

Aggravating factors could reclassify your DWI into the next higher level of offense. If you have a child passenger in the car during the offense, then your DWI is a state jail felony. A state jail felony is punishable by:

  • Up to 24 months in state jail; and
  • A possible fine of up to $10,000

Back to top

Drug Recognition Experts in Harris County, Texas

Texas has developed a new way for law enforcement to detect drug use. The International Association of Chiefs of Police (IACP) developed a curriculum which instructs police officers on how to identify people under the influence of drugs. Successfully completing the program will earn a police officer the title of Drug Recognition Expert (DRE). DRE utilizes a 12-step procedure to determine if a person has used drugs, which include:

  • Question the driver to evaluate their awareness;
  • Administer a breathalyzer test;
  • Examine their eye-tracking with exercises and compelling questions;
  • Evaluate their eyes with the Horizontal Gaze Nystagmus (HGN0, the Lack of Convergence (LOC) and the Vertical Gaze Nystagmus (VGN);
  • Use field sobriety tests to measure physical and mental faculties;
  • Examine vital signs such as blood pressure, pulse or body temperature;
  • Assess their pupil size with a penlight and pupilometer;
  • Evaluating their muscle tone;
  • Checking their arms for any injection sites;
  • Question the driver about suspicious evidence found in the 12-step process; and
  • Obtain a urine or blood sample for testing.

Back to top

Additional Resources

Drugged Driving – Visit Get Smart About Drugs, a Drug Enforcement Administration (DEA) resource for educators and parents. Access the site to find infograms surrounding drug-impaired driving, DWI statistics and answers to frequently asked questions. Impaired Driving Statistics – Visit the official website of the Center for Disease Control and Prevention to statistics detailing DUI and DWI incidents. Access the site to learn how frequent drug-related DWI is, the cost of DWI per year and what are the effects of BAC.

Lawyer for Drug Impaired DWI in Harris County, Texas

If you or someone you know has been charged with drug-related DWI, it’s vital you contact an experienced criminal defense attorney. Law enforcement can still detect drug-use through chemical testing. Not only this, but they now have Drug Recognition Experts who can identify drug use through their training. Don’t take your chances with DWI charges.

Call Tyler Flood & Associates, Inc. to gain trusted legal representation today. Our firm prides themselves on providing quality legal service to all clients. We can discuss your charges and start the first steps of your defense plan. Contact us at (713) 224-5529 to schedule a free consultation. Tyler Flood & Associates, Inc. defends clients throughout the greater Harris County area including Bellaire, Houston, West University Place and Pasadena.

This article last updated on March 7th, 2019.


Use the form to submit your request for a free consultation.

*Use of this form does not constitute an attorney-client relationship.

Driving While Intoxicated (Blood Draw .16)
Client had bond forfeited while case was pending for not being able to attend trial when Judge ordered us to be there due to his teaching job at Texas A&M University. When he more
Read More Case Results
Tyler Flood & Associates
2019 Washington Ave. #300
Houston, TX 77007
(713) 224-5529
Get Directions to Our Office


Disclaimer: The information on this website does NOT constitute legal advice. If you need legal advice, then retain an attorney to discuss the facts of your case. If you would like to discuss your case with an attorney at Tyler Flood & Associates, Inc., then please contact us to schedule a consultation. Until we specifically agree to act for you on a matter, you should not provide us with any confidential information or material.
Copyright © 2023 Tyler Flood & Associates, Inc.
linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram