I've got a probation revocation where the Defendant has a DWI in another county with the following levels:

Carisoprodol (Soma) = 17 mg/l

Meprobamate (Miltown) = 56 mg/l

Anybody have any experience with cutoff levels for either of these drugs? I was curious to see if there was a medically accepted level above which a person would be impaired. Reading the offense report, it appears the Def was quite out of it. I don't have the video yet.

http://www.nhtsa.dot.gov/people/injury/research/job185drugs/carisoprodol.htm

check out this web page and the "interpretation of blood test results" section.

From the perspective of a DRE I will tell you that the blood levels oare fairly irrelevant other than to establish a "medically accepted" level. Prescription drug dosages are based on what are referred to as an ED 50 and an LD 50, meaning an effective dose for 50% of the normal population and a lethal dose for 50%. Drug users tend to build up a tolerance to the drug over a period of time and, therefore, will require a large dose to have the same effect. This larger dose will naturally result in a higher blood concentration.

You are far better off treating this like a DWI without any test and concentrating onthe obvious and observed impairment.

NHTSA publishes a Drugs and Human Performance fact sheet on Carisoprodol and Meprobamate that you need to review. I have cut and pasted the blood and urine interpretation sections below for your reference.

Interpretation of Blood Concentrations: Following therapeutic doses of carisoprodol, blood concentrations are typically between 1 and 5 mg/L for carisoprodol, and between 2 and 6 mg/L for meprobamate. A single oral dose of 350 mg carisoprodol produced average peak plasma concentrations of 2.1 mg/L carisoprodol at one hour, declining to 0.24 mg/L at 6 hours. Following a single oral dose of 700 mg, average peak plasma concentrations of carisoprodol were 3.5 mg/L at 45 minutes, and meprobamate concentrations of 4.0 mg/L were obtained in 220 minutes. A single oral dose of 700 mg carisoprodol has also produced peak plasma concentrations of 4.8 mg/L carisoprodol. Following administration of meprobamate in the treatment of anxiety, concentrations are typically around 10 mg/L, but can range between 3 and 26 mg/L. A single oral dose of 1200 mg meprobamate produced concentrations of 15.6 mg/L at 4 hours. Plasma meprobamate concentrations of greater than 100 mg/L have been associated with deep coma; light coma between 60 and 120 mg/L; and patients with levels below 50 mg/L are invariably conscious.

Interpretation of Urine Test Results: Both drugs are excreted into the urine and are likely be detectable for several days following cessation of use. Less than 1% of a single oral dose of carisoprodol is excreted unchanged in the 24 hour urine, with meprobamate accounting for 4.7% of the dose. Following administration of meprobamate, up to 11% of a single dose is excreted in the urine in 24 hours. fact sheet on Carisoprodol and Meprobamate

I tried a DWI blood draw case where the Defendant was taking xanax and soma. Keep in mind that meprobamate is a metabolite of soma and will show up in a blood or urine test even if the person is not taking meprobamate as an individual drug. My toxicologist testified about theraputic levels, but there is no set level that renders someone intoxicated. I focused on the video and backed up the loss of the normal use of the mental and physical faculties by using the toxicologist to explain the CNS depressant qualities of the drug and the additive effect that takes place when drugs are combined.

Well, Dustan, what happened? Did you win? What did the jury say afterwards?

The jury found her guilty. The defendant had a prescription for both medications and her defense was that she had a xanax induced seizure (which btw, does not exist). The jury said that they originally had an issue with her having a prescription, but when they saw the video and heard the boyfriend testify about keeping her pills locked in a safe so there is no way she could have taken too many, it was easier to convict.