A bad reaction to cannabis can involve extreme anxiety, panic, confusion, paranoia, hallucinations, a fast heart rate, vomiting, poor coordination, or severe drowsiness. A fatal overdose caused only by cannabis is unlikely, but cannabis is not harmless and serious symptoms, injuries, interactions, contaminants, or another medical condition can occur.
Do not tell yourself or someone else that every symptom is “just THC.”
Immediate safety steps
- Stop taking cannabis, CBD, alcohol, and other drugs.
- Sit or lie somewhere safe and quiet. Do not drive, ride, swim, use stairs alone, or operate equipment.
- Ask a trusted sober person to stay nearby.
- Keep the product package and note what was taken, how much, when, and what else was used.
- If awake and not vomiting, sip fluids normally. Do not force food, excessive water, or supplements.
- Call the Ramathibodi Poison Center at 1367 for 24/7 poisoning advice.
Calm surroundings and slow breathing may help panic, but they are not treatment for chest pain, breathing difficulty, collapse, or severe confusion.
Call 1669 now for emergency signs
Call Thailand emergency medical services at 1669 for:
- chest pain, severe breathing difficulty, collapse, or fainting;
- seizure, inability to wake, or severe weakness;
- severe confusion, hallucinations, aggression, or dangerous behaviour;
- severe or persistent vomiting;
- suspected unknown or synthetic cannabinoids;
- serious injury; or
- any rapidly worsening symptom.
Get professional advice sooner for a child, pregnancy, an older adult, significant heart disease, or when cannabis was combined with alcohol, medicines, or unknown substances.
Skip unsupported “antidotes”
Peppercorns, lemon, sugar, caffeine, cold showers, and retail CBD are not proven antidotes. They can delay appropriate care, add interaction risk, or create injury risk in a dizzy person. Follow advice from the poison centre or clinician instead.
Edibles may worsen after a delay
The CDC cannabis-poisoning guidance notes that edible effects may take 30 minutes to 2 hours to appear and can last longer than expected. Do not take more while waiting, and do not assume symptoms have peaked early.
After the immediate episode
Do not drive until all impairment has resolved. If reactions recur, tolerance is rising, cutting down is difficult, or use is affecting sleep, mood, work, or relationships, stop and speak with a qualified clinician.
FAQ
Can cannabis cause a medical emergency?
Yes. A fatal overdose caused solely by cannabis is unlikely, but poisoning, severe symptoms, injuries, interactions, and exposure to unknown products can require urgent care.
Should I make someone vomit?
No. Do not induce vomiting unless a poison specialist or clinician specifically instructs you to do so.
Should I give them CBD or black pepper?
Do not rely on either as an antidote. Call the poison centre for case-specific advice.
Who can I call in Bangkok?
Ramathibodi Poison Center: 1367, 24/7. Emergency medical services: 1669.
