Thursday, March 16, 2017

Ithaca DWI Lawyer: Zero Order Kinetics and THC

Zero Order versus First Order
The first drug that was recognized to cause issues with driving was alcohol. Being the most common, socially accepted, legal, readily available, and used substance on the planet alcohol has been studied intensively. Alcohol was easily measured and understood.

New York State as well as the rest of the country found setting specific BAC (blood alcohol concentration) thresholds rather simple. NYS even  separated out intoxication (.08 or more), from impairment (.06 to .07). Now with marijuana use and abuse on the rise everyone wants to apply alcohol terms, alcohol tests, and alcohol pharmacological kinetics to THC.

What does "zero order kinetics" have to do with Alcohol and THC? How can we better defend New York DWAI drugs THC cases from alcohol prosecution?

Alcohol and Intoxication Follows Zero Order Kinetics When Eliminating From The Body

Alcohol is one of few drugs that has a very steady, orderly, and linear elimination phase. Remember alcohol is absorbed, distributed, and then eliminated from the body. Based on how much you drink, what you eat, and over what time an educated guess can be made of your BAC levels. Because alcohol follows a straight elimination of approximately .02 BAC per drink per hour. So roughly 5 drinks will raise your BAC .02 x 5 = .10, with a total Blood Alcohol Concentration at peak of about .10 will then reduce to about .06 BAC within two hours.

THC Follows First Order Kinetics in Eliminating from the Body

It's all about half-life
BUT the vast majority (95%) of drugs and substances DO NOT follow zero order kinetics like alcohol. Their non-linear (exponential) trajectories follow first order kinetics in that the drug's half life must be calculated and is constantly changing over time. Alcohol is also water soluble so breaks down and is released almost completely by the body over time. Many drugs, like THC are fat-soluble and may still reside within the body for weeks or months.

DWAI Drugs THC in New York State Can Be Defended By Using First Order Kinetics

Many police officers and lab toxicologists want us to use alcohol as a model for understanding marijuana pharmacology. If we don't know all the variables concerning THC half life, and the specifics for your elimination period of marijuana then one blood test one time doesn't tell us your BAC level at time of driving.

It would take seven different blood draws over time to accurately gauge THC at the time of driving. Even then that level alone doesn't tell us the amount of impairment by the THC level, was there truly any mental or physical impairment of your abilities to drive? Even then can the officer asking you to walk a straight line (an alcohol test) use that test to say you were too stoned to drive?

There are many issues to explore in defending marijuana while driving (DWAI DRUGS), and making the leap from applying alcohol DWI to drugs DWAI is not as easy as many believe.