Abstract
Objectives
To monitor cannabis intoxication in emergency departments in public hospital. The
monitor includes both intoxication from medical cannabis and cannabis use for other purposes.
Methods
The surveillance was conducted in patients visiting emergency rooms with a history of
cannabis use or were found to have symptoms caused by cannabis. Four surveillance sites were
Maharaj Nakorn Chiang Mai Hospital (Chiang Mai), Thammasat Chalermprakiet Hosipital (Pathum
Thani), Srinakarin Hospital (Khon Kean) and Songklanagarindra Hospital (Songkhla). The total
surveillance period was 12 months from September 16, 2023 to September 15, 2024.
Key finding
Within 12-months surveillance, the total of 51 volunteers were included in the study.
There were more male than female. With 35 volunteers were male (68.63 %). The average age
were 30.04 years old. Urine THC tested positive in 38 cases of 40 cases tested (95%). Most
volunteers had no underlying medical conditions.
Physical symptoms were most prevalent in volunteers with cannabis intoxication.
Palpitation and mouth dryness were the most common symptoms (found in more than half of
the volunteers). Dizziness, nausea, vomiting and drowsiness were the next most common
symptom (ranging from 30-50%) Mental symptoms were found in 33% of volunteers including
dysphoria, fear, panic, Psychomotor impairment, and psychosis. Most volunteers had mild
symptoms. Only 2 volunteers (3.92%) were admitted for in-patient care.
Forty-three volunteers (84.31%) had history of cannabis use. About half of the volunteers
smoked cannabis (52.94%). Other cannabis products included cannabis-infused snacks in 20
volunteers (39.22%), cannabis oil in 5 volunteers (9.80%), and cannabis pill/ cannabis in a form
of herbal medicines in 1 volunteer (3.92%). The purposes of use were entertainment in 20
volunteers (39.22%), sleep aid in 10 volunteers (19.61%), mood improvement in 10 volunteers
(19.61%), unintentional use in 5 volunteers (9.80%), experimentation in 4 volunteers (7.84%),
pain relief in 1 volunteer (1.96%), health maintenance in 1 volunteer (1.96%), and unknown
purposes in 6 volunteers (11.76%). THC, CBD and 11-OH-THC levels were measured in plasma from 25 volunteers (49.02%).
THC was detected in all plasma samples, with an average concentration of 1.810 ng/ml. The
minimum THC level was 0.198 ng/ml, and the maximum was 10.473 ng/ml. CBD was detected in
24 plasma samples (96% of plasma samples), with an average concentration of 0.358 ng/ml. In
13 samples (54% of CBD-detected plasma), the CBD level was less than 0.1 ng/ml, and the
maximum CBD level was 5.073 ng/ml. 11-OH-THC were also detected in all plasma samples with
an average level of 1.600 ng/ml. The minimum 11-OH-THC level was 0.072 ng/ml, and the
maximum was 6.985 ng/ml.
Twenty urine samples were collected (39.22%). COOH-THC were detected in 19 urine
samples (95% of urine samples). The average level of COOH-THC was 196.330 ng/ml (maximum
1318.098 ng/ml). Urine COOH-THC levels did not show a direct correlation with plasma THC
levels, as multiple factors can influence the excretion of COOH-THC in urine. One important
factor is that regular use of THC results in higher concentrations and a longer duration of COOHTHC detection in urine compared to single use.
Co-use of other substances was found in 21 volunteers (41.17%). The most common coused substance was alcohol, found in 12 volunteers (23.53%). Other substances were Kratom in
4 volunteers (7.84%), tramadol in 3 volunteers (5.88%), methamphetamine in 1 volunteer
(1.98%), opioid in 1 volunteer (1.98%) and sleeping pill in 1 volunteer (1.98%).
Opinion of the research team
During the early period of cannabis legalization, there were more patients presenting to
the emergency department with cannabis intoxication compared to the period during which our
data were collected. In the opinion of the research team, this may be because new users were
not yet familiar with the symptoms associated with cannabis use. As the number of new users
declined, previous users became more aware of the effects of cannabis and understood that
these effects are typically not life-threatening. Some cases of cannabis intoxication were the
result of accidental ingestion. Regulations should be implemented to permit cannabis use only
for medical purposes in order to minimize negative societal impacts.
Our research team also found that some cannabis users were adolescents. Cannabis use
during adolescence can have long-lasting effects on brain development. Most adolescent
cannabis users used cannabis for recreational purposes. Therefore, stricter regulations and better
monitoring systems should be established to prevent cannabis access among adolescents.
Further studies on the health and social effects of cannabis use should be considered.
The research team suggests anonymized data collection to help ensure unbiased results, given
the high rate of participation denial and possible fears of legal consequences among potential
participants.
