A patient with a history of opioid abuse is scheduled for nitrous-oxide sedation. He denies recent drug use but smells of marijuana. The best action is to:

Correct answer: B. Reschedule and advise him not to use substances before the appointment

• A. Combining sedation with recent cannabis risks tachycardia and unpredictable response.
• B. Correct. Reschedule; sedating a patient who is acutely intoxicated is unsafe (cardiovascular/CNS interactions).
• C. Increasing the dose increases risk.
• D. Escalating to IV sedation in an intoxicated patient is more dangerous, not safer.