What is the management approach for a patient with THC (Tetrahydrocannabinol) intoxication after consuming 100mg?

Management of THC Intoxication After Consuming 100mg

Supportive care with IV fluids, butyrophenones for severe nausea/vomiting, and complete abstinence from further cannabis use is the recommended treatment approach for THC intoxication after consuming 100mg. 1

Initial Assessment

• Evaluate vital signs with particular attention to:

  • Heart rate (tachycardia is common)
  • Blood pressure (orthostatic hypotension may occur)
  • Respiratory status
  • Mental status (anxiety, paranoia, hallucinations)

• Rule out life-threatening conditions with basic workup:

  • Complete blood count
  • Electrolytes
  • Glucose
  • Liver function tests
  • Lipase
  • Urinalysis

Treatment Algorithm

For Mild to Moderate Symptoms

1. Reassurance and calm environment
2. Oral hydration if tolerated
3. Monitor vital signs
4. Observe for 4-6 hours (effects of oral THC can last 4-12 hours) 2

For Severe Symptoms

1. IV fluid rehydration for dehydration

2. For severe nausea and vomiting:

   • Butyrophenones (haloperidol 2-5mg or droperidol) 1
   • Topical capsaicin (0.1%) cream applied to the abdomen
   • Hot showers/baths for symptom relief

3. For severe anxiety/agitation:

   • Avoid benzodiazepines if possible due to potential drug interactions 1
   • If necessary, use lowest effective dose with close monitoring

4. For persistent vomiting concerning for Cannabinoid Hyperemesis Syndrome (CHS):

   • IV fluid rehydration
   • Butyrophenones have shown better efficacy than traditional antiemetics 3

Special Considerations

Cardiovascular Effects

• Monitor for tachycardia and orthostatic hypotension
• Patients with pre-existing cardiovascular disease require closer monitoring 3

Central Nervous System Effects

• Assess for altered mental status, anxiety, paranoia, hallucinations
• High-dose THC (100mg is considered a very high dose) can cause fear, distrust, hallucinations, ataxia, stupor and rarely seizures 4

Respiratory Effects

• If THC was smoked, monitor for respiratory complications
• Consider oxygen supplementation if indicated

Patient Education and Discharge Planning

1. Advise complete abstinence from cannabis until fully recovered
2. Warn against driving or operating machinery until effects completely resolve (minimum 24 hours) 1
3. Explain that symptoms typically resolve within 24-48 hours for acute intoxication
4. If symptoms persist beyond 48-72 hours, consider follow-up evaluation

Pitfalls and Caveats

• Avoid opioids as they can worsen nausea and carry addiction risk 1
• Be aware that THC inhibits several Phase I and II metabolism enzymes, which can increase exposure to other medications 5
• Children and adolescents are more susceptible to cannabis toxicity, particularly seizures and coma, requiring more aggressive supportive care 4
• 100mg THC is an extremely high dose, far exceeding the recommended therapeutic daily limit of 30mg 6
• The intensity and duration of symptoms is proportional to the concentration of THC in the blood 4

For patients with recurrent episodes suggesting Cannabis Hyperemesis Syndrome, complete abstinence for at least 6 months is required for resolution 1.