Many people think that you can’t overdose when using cannabis and delta-9-tetrahydrocannabinol (THC) because they’re generally safe and natural, and it’s usually just difficult to do. A recent accident reported in the New England Journal of Medicine argued the opposite. 
A 52-year old man was taken to the emergency room at the Hospital of the University of Pennsylvania in Philadelphia with severe, hyperactive delirium. The man was awake, but incapable of answering questions. His wife told the doctors he had been experiencing “progressive restlessness and garbled speech” for the past two days.
Because the man had an anaplastic astrocytoma, a rare malignant brain tumor, doctors did “computed tomography of the head and magnetic resonance imaging of the brain,” which revealed no changes from previous tests’ results. To deepen the mystery, “laboratory evaluation revealed normal electrolyte levels and normal liver function, and serum toxologic screening was negative for ethanol,” the doctors explained.
But then a possible missing clue was discovered — a syringe amidst the man’s medications. It turned out that the man had started using a cannabis oil two days prior to his emergency room admission, which coincided with the symptoms that his wife described. He was using cannabis to stimulate his appetite.
The article reports that the man used approximately two-thirds of a 500 mg, 66% THC oil. This means the man consumed approximately 330 mg of 66% THC oil in two days. For reference, “a typical recreational dose of THC for persons who have not previously used [cannabis] is 10 mg,” the authors commented.
Luckily, under medical supervision, the man’s symptoms died down, and eventually he stabilized. The authors suggest the development of standardized dosing, something currently absent in many states. “With the increasing use of medical [cannabis], it is time for regulations to standardize and monitor these substances,” the study’s authors wrote. 
But, cannabis and it’s downstream products present complexities like any other medicine. Different people require different dosages based on physical attributes like body weight. Medical dosing, of course, depends on factors such as the severity of a patient’s medical symptoms. This man had a malignant brain tumor and wasn’t seeking recreational pleasure.
While overconsuming THC shouldn’t be taken nonchalantly, there are factors that could be catalysts for the emergency that this case turned into. The patient had a serious preexisting condition, which inserted unpredictability into the equation. He took a sizeable dose of THC. It’s unclear if he had a previous history with cannabis to have a reference point for a “regular” THC dose. So, taking 330 mg of a cannabis oil that’s 66% THC (approximately 218 mg actual THC) over two days for a beginning user could obviously present problems.
Although the National Institute on Drug Abuse has said that there hasn’t been an adult death from THC, a coroner labeled a 2019 death as resulting from THC [oil]. Interestingly, the coroner claimed that “I’m thinking this lady must have vaped this THC oil and got a high level in her system and (it) made her stop breathing, like a respiratory failure.” Apparently, the coroner didn’t know that cannabinoid receptors, unlike opioid receptors, are quite scant in the brainstem which controls respiration. 
Keith Humphreys, a former senior policy adviser at the White House Office of National Drug Control Policy, explained to the New Orleans Advocate, however, that ‘’if the risk of death was one in a million, we would have a couple thousand of cannabis overdose deaths a year.” Given that millions of people have been smoking and ingesting cannabis for a very long time, where’s that evidence of thousands of overdoses per year?
In most cases, THC overconsumption might be alleviated by a drink of water, a change of scene, some soothing words, and a bit of time for symptoms to taper off, rather than an expensive ride on an ambulance. This isn’t at all to say that medical treatment might not be necessary. But a little prior education goes a long way, and so those new to cannabis are advised to understand the effects that cannabis can produce, rather than facing this knowledge during the cannabis experience, whether using therapeutically or “recreationally”.
- Mudan AA, et al. “Medical Marijuana Miscalculation.” N Engl J Med, vol.381, 2019. Journal Impact Factor = 70.670; Times Cited = 2 (NEJM)
- Herkenham, M. et al. “Cannabinoid receptor localization in brain,” Proc Natl Acad Sci U S A, vol. 87(5), 1990, pp. 1932-6. Journal Impact Factor = 9.58; Times Cited = 1799 (ResearchGate)
Image Credits: buoy