A very powerful herb has swept the market, raising concerns about health risks

As more and more states legalize marijuana, more and more people in the US are buying and using grass – and the type of grass they can buy has become much more powerful.

This concerns scientists who are studying marijuana and its effects on the body, as well as emergency room doctors who say that they are starting to see more patients coming into the emergency with problems. associated with weeds.

According to the National Survey of Drug Use and Health, about 26 million Americans aged 12 and over reported consuming marijuana in 2017. It is unclear how many users have had serious health problems caused by a strong herb, and the potential risks are not yet known. But scientists are beginning to learn more about some of them.

The power of the weed depends on the amount of delta-9-tetrahydrocannabinol, or THC, the main compound responsible for the psychoactive effects of the drug. A study on potted products seized by the US Drug Enforcement Administration revealed that its activity had increased from about 4% of THC in 1995 to about 12% in 2014. In 2017, another study showed that The efficacy of the illicit drug samples had increased to 17.1% THC. .

"This represents an increase of more than 300% between 1995 and 2017," says Staci Gruber, director of the Marijuana Investigations for Neuroscience Discovery (MIND) program at Harvard-affiliated Harvard Hospital in Belmont, Massachusetts. . "I would say it's a huge increase."

And some products containing concentrated forms of cannabis, such as hashish and hash oil, can contain between 80% and 90% THC, she adds.

"I think most people are aware of the following phenomenon:" This is not the weed of your grandfather, "says Gruber. I hear that all the time. "

But people may not be aware of the potential health risks of a very potent herb. "The negative effects of cannabis have been mostly isolated and localized to THC," said Gruber. "So, needless to say, higher levels of THC may actually confer a higher risk of negative outcomes."

"In general, people say to themselves," Oh, I do not have to worry about marijuana. It's a safe drug, "said Nora Volkow, director of the National Institute for Combating Drug Abuse. "The idea that this drug is completely safe is incorrect when you start to tackle the consequences of this very high 9THC content."

The paradoxical effects of the pot

THC can have opposite effects on our body at high and low doses, says Volkow. Take the levels of anxiety, for example.

"When someone takes marijuana at the lowest [THC] happy to relax and extricate themselves, in fact, your anxiety diminishes, "she says. But high concentrations can cause panic attacks, and if a person consumes enough THC, "you become psychotic and paranoid in their own right."

Weeds can have a similar paradoxical effect on the vascular system. Volkow says, "If you take low-content THC, it will increase your blood flow, but high content [THC] can produce a massive vasoconstriction, it decreases the flow in the vessels. "

And at low concentrations, THC can be used to treat nausea in cancer patients undergoing chemotherapy. But Volkow said that "patients who chronically consume high-THC THC arrived at the emergency department with a syndrome where they could not stop vomiting and with severe abdominal pain."

It is a disease called cannabinoid hyperemesis syndrome.

"The typical patient uses [inhales] about 10 times a day (…) and they really have trouble treating nausea and vomiting, "says Andrew Monte, associate professor of emergency medicine and medical toxicology at the medical school from the University of Colorado. " Some people have died from this death … syndrome, so it is worrying. "

Scientists do not know exactly how high levels of THC can trigger the syndrome, but the only known treatment is stopping cannabis use.

Although the number of people with the syndrome is low, Monte says that he and his colleagues have documented an increase in the number of cases in Colorado's emergency rooms since the legalization of marijuana there is five years. A study by Monte and his team revealed that cases of cyclic vomiting constituted about 18% of cases related to the inhalation of cannabis related to inhalation in its emergency department.

They also found that the total number of ER cases associated with cannabis use had increased across the state. And Monte says his emergency department has "seen about three times more emergency department visits than by frequency." That does not mean we're overwhelmed by these visits because of cannabis, it's just that it means that there are more patients overall. "

Most people come to their emergency department because of an "intoxication" caused by an excess of pot, directly or in combination with other medications, Monte says. The majority of these cases are due to the inhalation of cannabis, although edible products are associated with more psychiatric visits.

"We are seeing an increase in psychosis and hallucinations, as well as anxiety and even depression and suicidality," Monte said.

He thinks that the increased potency of marijuana plays a role in all these cases. "Whenever you take a higher dose of any of these types of medications, the patient has a higher risk of adverse effect to the drug.If the concentration is much higher … it is it's much easier to go beyond the lowest level. " they are looking for. "

Everyone does not run the same risk, adds Monte. "Many people use cannabis safely," he says. "The vast majority do not end up in our emergency department."

Different risks for users

Some people are more vulnerable than others to the potential negative effects of high-THC cannabis.

Adolescents and young adults who use recreational activities are particularly susceptible because their brains are still developing and are sensitive to drugs in general, says Gruber of the MIND program. In a recent study of existing studies, she discovered that marijuana use among adolescents affects cognition, especially memory and executive functions, which determine mental flexibility and the ability to change our behavior.

Marijuana users for medical purposes may face unexpected and unwanted effects from a weed. "It's very important that people understand that they may not get the expected answer," Gruber points out.

The studies on the medical benefits of the pot usually involve very low doses of THC, Monte said, adding that these doses "are well below what people currently get in a clinic."

David Dooks, a 51-year-old Boston resident, turned to marijuana after an ankle surgery last year. "I thought marijuana for medical purposes could be a good alternative to opioids for pain management," he says.

According to the advice of a dispensary, David began using a variety of weeds containing 56.5% THC and said that this "only exacerbated the nerve pain". After experimenting with a few other strains, he said, what worked for him was the one with a low THC content (0.9%), which eased his nerve pain.

"Start low, go slowly"

Whether people use for recreation or medical purposes, patients should educate themselves as much as possible and be careful when using them, says Monte.

Avoiding products with higher THC content and using it rarely can help reduce risk, adds Volkow. "Anyone who has had a bad experience, whether it is psychological or biological, must stay away from this drug," she notes.

Ask as much information as you can before you buy. "You have to know what's in your grass," says Gruber. "Whether it's a classic flower that you smoke or spray, dye or dye, it's very important to know what's going on." there is in it. "

And the old adage "start low, go slowly" is a good rule, she adds. "You can always add, but you can never take it off, once it's in it, it's in it."

Copyright NPR 2019.