Combination of alcohol, marijuana increases THC in blood

By Stacey Marquis • Published: August 6th, 2015
Category: Health in a Heartbeat

Twenty-three states and the District of Columbia have legalized medical marijuana, while a handful of other states have decriminalized it. With this growing acceptance comes a greater need to understand how the drug interacts with alcohol.

A small study appearing in the journal Clinical Chemistry examined the effect alcohol has on marijuana’s psychoactive chemical, tetrahydrocannabinol (tet-rah-high-droh-can-A-bin-ahl) or THC. In their study, the researchers found that when alcohol and marijuana were combined, the alcohol seemed to increase the amount of THC in the bloodstream, compared to marijuana used on its own.

Before reaching this conclusion, researchers gave a group of adults different concentrations of alcohol and THC. The participants were given either a placebo or low-dose amount of alcohol. Ten minutes later, they inhaled different amounts of vaporized cannabis: a placebo amount, a low-dose THC amount or a high-dose THC amount.

The researchers found that when participants didn’t have any alcohol in their system, their median blood concentrations of THC were 32.7 micrograms and 42.2 micrograms. However, the participants who did have alcohol in their system had median blood THC concentrations of 35.3 micrograms and 67.5 micrograms, showing a significant increase.

This increase may explain why cannabis and alcohol is one of the most frequent drug combinations in car accidents.

These results might impact states such as Colorado, where medical and recreational marijuana is legal. In this state there are already laws in place that ban drugged driving. If a driver has five nanograms of THC per milliliter of blood shown through a chemical test, he or she is considered impaired.

No matter your state, it’s always best to play it safe and not drive under the influence of any substance.