DWI Blood Tests Can Reveal Prescription Drugs

Texas authorities are relying more and more on blood testing to determine whether a driver may have been operating a motor vehicle while intoxicated.

In 2010, the crime lab at the Texas Department of Public Safety — the agency where DWI blood tests are sent– processed around six thousand cases. By 2012, that workload had increased to over 7,000 tests. To meet the additional demand, the crime lab in Austin has requested a staff increase of about 12 additional forensic scientists. The lab may also have to invest in additional or new analysis hardware.

The additional blood testing has also uncovered a surprising result: Some Texas drivers are operating their vehicles under the influence of prescription or illegal drugs, rather than alcohol. Some of the most common drugs include Soma, Xanax, and hydrocodone. In other cases, a driver may have self-dosed beyond the recommend dosage.

Yet even in the case of doctor-prescribed, lawful medications, a driver may face criminal consequences if the medication impaired his or her driving. Unlike DWI charges, however, the determination of what constitutes unsafe levels of a prescription drug may be less straightforward. For example, there may not be an equivalent of a blood alcohol content chart or a state law defining the legal blood alcohol limit, both of which are often typical evidence in DWI cases.

What this means for a driver charged with driving under the influence of drugs is that a defense will likely have to involve additional evidence, not only about the medication at issue, but also its effects on various individuals. An experienced DWI drug attorney will know which experts to reach out to in preparing that defense.