Physicians need to be educated about marijuana, resident argues

 

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Nathaniel Morris, MD, a resident in psychiatry at Stanford, said he learned almost nothing about marijuana during medical school. Its absence made some sense, he explained in a recent JAMA Internal Medicine editorial: why focus on marijuana when physicians must worry about medical emergencies such as cardiac arrest, sepsis, pulmonary embolisms and opioid overdoses?

However, marijuana use has dramatically changed in the few years since he earned his medical degree, he pointed out. Thirty-three states and Washington, D.C. have now passed laws legalizing some form of marijuana use, including 10 states that have legalized recreational use. And the resulting prevalence of marijuana has wide-ranging impacts in the clinic.

“In the emergency department, I’ve come to expect that results of urine drug screens will be positive for tetrahydrocannabinol (THC), whether the patient is 18 years old or 80 years old,” he said in the editorial. “When I review medications at the bedside, some patients and families hold out THC gummies or cannabidiol capsules, explaining dosages or ratios of ingredients used to treat symptoms, including pain, insomnia, nausea, or poor appetite.” He added that other patients come to the ED after having panic attacks or psychotic symptoms and physicians have to figure out whether marijuana is involved.

Marijuana also impacts inpatient units. Morris described that some patients smuggle in marijuana and smoke in their rooms, while others who abruptly stop their use upon entering the hospital experience withdrawal symptoms like sleep disturbances and restlessness.

The real problem, he said, is that many physicians are unprepared and poorly educated about marijuana and its health effects. This is in part because government restrictions have made it difficult to study marijuana, so there is limited research to guide clinical decisions.

Although people have used marijuana to treat various health conditions for years, the U.S. Food and Drug Administration (FDA) has not approved the cannabis plant for treating any health problems. The FDA has approved three cannabinoid-based drugs: a cannabidiol oral solution used to treat a rare form of epileptic seizures and two synthetic cannabinoids used to treat nausea and vomiting associated with cancer chemotherapy or loss of appetite in people with AIDS.

In January 2017, the National Academies of Science, Engineering, and Medicine published a report that summarizes the current clinical evidence on the therapeutic effects and harmful side effects of marijuana products. However, more and higher quality research is needed, Morris said.

Physicians also need to be educated about marijuana through dedicated coursework in medical school and ongoing continuing medical education activities, he said. Morris noted that physicians should receive instruction pertinent to their fields — such as gastroenterology fellows learning about marijuana’s potential effects on nausea or psychiatry residents learning about associations between marijuana and psychosis.

“These days, I find myself reading new studies about the health effects of marijuana products, attending grand rounds on medical marijuana, and absorbing tips from clinicians who have more experience related to marijuana and patient care than I do,” Morris said. “Still, I suspect that talking with patients about marijuana use and what it means to them will continue to teach me the most.”

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Saliva tests may help identify marijuana-impaired drivers

Photo by ashton
Photo by ashton

As of the recent election, seven states and the District of Columbia have now legalized marijuana for recreational use and 19 other states have legalized medical marijuana. And this legalization has raised concerns about driving under the influence of marijuana.

A number of research groups are now focusing on ways to identify drivers impaired by marijuana. As recently reported by KQED, the Center of Medicinal Cannabis Research at the University of California, San Diego, are working to “gather data about dosages, time and what it takes to impair driving ability — and then create a viable roadside sobriety test for cannabis.” And a group of Stanford engineers have created a test called a ‘potalyzer.’

The Stanford effort was led by Shan Wang, PhD, a Stanford professor of materials science and engineering and of electrical engineering. He and his colleagues developed a mobile device that detects the amount of tetrahydrocannabinol (THC) molecules in saliva. (THC is the main psychoactive agent in marijuana.)

The test would allow police officers to collect a saliva sample from the driver’s mouth with a cotton swab, analyze it with the new device, and then read the results on a smartphone or laptop in as little as three minutes.

The technology combines magnetic nanotechnology with a competitive immunoassay. During the test, saliva is mixed with antibodies that bind to both THC molecules and magnetic nanoparticles. The mixture is placed on a disposable test chip, inserted into the handheld device and the THC-antibody-nanoparticles are detected by magnetic biosensors. The biosensor signal is then displayed on a Bluetooth-enabled device.

Wang’s group focused on developing a THC saliva test because it is less invasive and may correlate better with impairment than THC urine or blood tests. Also key is the need for a very sensitive test. A Stanford news release explains:

“Wang’s device can detect concentrations of THC in the range of 0 to 50 nanograms per milliliter of saliva. While there’s no consensus on how much THC in a driver’s system is too much, previous studies have suggested a cutoff between 2 and 25 ng/ml, well within the capability of Wang’s device.”

There is still a lot to do before police can deploy this ‘potalyzer’ device, including making it more user-friendly, getting it approved by regulators and investigating whether there is a better biomarker to detect marijuana impairment than THC. In addition, the test may not work well for THC edibles, the researchers wrote in a recent paper published in Analytical Chemistry.

On the upside, the Stanford technology could also be used to test for morphine, heroin, cocaine or other drugs — and for multiple drugs at the same time.

More research is needed, but there is now a new funding source in California: Proposition 64 allots millions of dollars per year to research marijuana and develop ways to identify impaired drivers.

This is an expanded version of my Scope blog story, courtesy of Stanford School of Medicine.