What is the recommended management of cannabis poisoning in children who accidentally ingest edibles and in adults with acute intoxication presenting with anxiety, agitation, tachycardia, or hypertension?

Management of Cannabis Poisoning

For children with accidental cannabis ingestion, provide supportive care with close monitoring for neurological and cardiopulmonary complications; for adults with acute intoxication presenting with anxiety, agitation, tachycardia, or hypertension, benzodiazepines are the primary treatment alongside supportive measures, with no role for activated charcoal or specific antidotes. 1, 2

Initial Assessment and Risk Stratification

Children (Accidental Edible Ingestion)

• Immediately assess for altered mental status, severe sedation, respiratory depression, or cardiovascular instability requiring emergency intervention 1
• Look specifically for neurological symptoms: drowsiness, agitation, abnormal behavior, ataxia, hypotonia, mydriasis, hypermetria, urinary incontinence, tremors, and in severe cases coma or seizures 3, 4
• Monitor for cardiopulmonary manifestations: tachycardia, bradypnea, apnea, hypothermia, and bradycardia 3, 4
• Children are significantly more susceptible to severe toxicity than adults, particularly seizures and coma, requiring heightened vigilance 4
• Recognize that edible cannabis has delayed onset (30 minutes to 2 hours) with peak effects at 2-4 hours, meaning symptoms may worsen significantly after initial presentation 1

Adults (Acute Intoxication)

• Assess for psychiatric symptoms: anxiety, panic attacks, psychosis with hallucinations, paranoia, fear, distrust, and profound unease 4, 2
• Monitor cardiovascular parameters: tachycardia, hypertension, potential arrhythmias, and orthostatic hypotension 1, 2
• Rule out life-threatening conditions (acute abdomen, bowel obstruction, mesenteric ischemia, pancreatitis, myocardial infarction) before attributing all symptoms to cannabis 1
• Individuals with pre-existing cardiovascular disease face elevated risk for myocardial infarction and stroke 1

Acute Management Protocol

Supportive Care (All Patients)

• No specific antidote exists for THC poisoning 4, 5
• Provide care in a calm, quiet environment to minimize agitation 1
• Establish continuous monitoring of vital signs: heart rate, blood pressure, respiratory rate, temperature, and cardiac rhythm 1, 2
• Do not administer activated charcoal - it has limited utility given rapid THC absorption and is not routinely recommended 3
• Maintain airway patency and provide supplemental oxygen if needed 6
• Administer intravenous fluids for hydration, temperature control, and to counter prolonged vomiting 5

Pharmacologic Management for Agitation/Anxiety

• Benzodiazepines are first-line for severe agitation, anxiety, or hyperexcitability 4, 5
• Use lorazepam 1-2 mg IV/PO or diazepam at appropriate weight-based dosing for sedation 7
• Titrate benzodiazepines to effect while monitoring for respiratory depression 5

Cardiovascular Symptom Management

• Cardiac monitoring is essential for tachycardia and potential arrhythmias 1
• Obtain baseline ECG and monitor QTc interval, as cannabis can prolong QT and increase arrhythmia risk 2
• Treat symptomatic tachycardia with benzodiazepines rather than beta-blockers initially 2
• For patients with chest pain or cardiovascular symptoms, do not delay evaluation for myocardial ischemia 1

Pediatric-Specific Considerations

• Anticipate more severe and prolonged symptoms in children compared to adults 3, 4
• Monitor continuously for the first 24 hours after intoxication 3
• Be prepared for active resuscitation measures including airway management if severe CNS or respiratory depression develops 3, 4
• Clinical course may include agitation and irritability episodes lasting up to 18 hours 3
• Hospital admission for 2-48 hours is typical for symptomatic children 8

Diagnostic Testing

• Urine cannabinoid screening is the primary diagnostic test, with 70% positivity rate in pediatric cases 8
• Blood screening for cannabinoids may be negative even with significant intoxication, as THC rapidly converts to metabolites 8
• Human urine drug-screening tests can be unreliable in the immediate post-ingestion period and may yield false negatives 5
• Check electrolytes (particularly potassium) and perform ECG monitoring in adults with cardiovascular symptoms 2

Critical Pitfalls to Avoid

• Never use opioids for symptom management - they worsen nausea and carry high addiction risk 7, 1
• Do not assume symptoms will be mild with edibles - they produce higher plasma concentrations and increased emergency department visit risk 1
• Avoid haloperidol or other antipsychotics for simple anxiety/agitation - reserve these for cannabinoid hyperemesis syndrome, not acute intoxication 7
• Do not discharge children or adults prematurely - symptoms can persist or worsen for hours after presentation 3, 2

Disposition and Follow-Up

Hospital Admission Criteria

• Children with any neurological symptoms, cardiopulmonary compromise, or inability to maintain hydration 3, 8
• Adults with persistent psychosis, cardiovascular instability, or inability to care for themselves safely 2
• Observation period of at least 24 hours for symptomatic children 3

Outpatient Management

• Schedule primary care follow-up within 1-2 weeks to screen for cannabis use disorder symptoms (irritability, insomnia, headaches) 1
• Screen for mental health sequelae including anxiety, panic attacks, depression, and psychotic symptoms 1
• Patients with cannabis psychosis are at elevated risk for further psychotic episodes and require psychiatric referral 2

Social Services Involvement (Pediatric Cases)

• All pediatric cannabis intoxications should be reported to child protective services to detect neglectful situations and at-risk families 8
• Referral for social services assessment is recommended before discharge, even when parents report accidental ingestion 8
• Consider legal action and prevention strategies to protect the child 8

Special Population Considerations

Older Adults (≥65 years)

• Face increased risk for sedation, obtundation, myocardial ischemia, falls from orthostatic hypotension, and ataxia 1
• Require heightened vigilance and prolonged monitoring 1

Patients with Pre-existing Conditions

• Cardiovascular disease: elevated risk for myocardial infarction, stroke, and arrhythmias 9, 1
• Respiratory conditions: potential for respiratory depression and bronchospasm 9
• Mental health disorders: risk of exacerbation and psychotic decompensation 9, 2

Expected Clinical Course

• Symptoms typically resolve within 24-48 hours with supportive care 3, 2
• Complete regression of symptoms is expected in the vast majority of cases without sequelae 3, 5
• Psychosis, hypokalemia, and QTc prolongation resolve over 2 days with minimal intervention 2
• Contact regional poison control center (1-800-222-1222 in US) for expert guidance on complex cases 6