What are the guidelines for patient education on the use of Tetrahydrocannabinol (THC)?

Patient Education on THC Use: Clinical Guidelines and Recommendations

Health systems and clinicians should provide patients with unbiased, evidence-based cannabis and THC educational resources to facilitate informed decision making about its use. 1

Screening and Assessment

• Clinicians should routinely and nonjudgmentally inquire about cannabis use (or consideration of use) and either guide care or direct patients to appropriate resources 1
• For patients consuming cannabis more than once per day, screening for cannabis use disorder (CUD) is appropriate and recommended 1
• Assessment should include estimating daily cannabis intake, duration of use, and method of consumption 1
• When taking a cannabinoid history, remain sensitive to cannabis regulations' disproportionate impacts on marginalized communities and avoid biases (racial, ethnic, socioeconomic) in clinical discussions 1

Dosing and Administration Guidelines

• Start with low doses and titrate slowly ("start low, go slow") to minimize potential adverse effects 2, 3
• THC's total daily dose-equivalent should generally be limited to 30mg/day or less to avoid psychoactive sequelae and development of tolerance 3
• Dose titration of any cannabis preparation should be undertaken slowly over a period of as much as two weeks 3
• A proposed "standard THC unit" is 5 mg THC for all cannabis products and methods of administration 4
• For oral THC, significant variability exists in absorption and effects, requiring individualized dose adjustment 5

Product Selection Education

• Educate patients on THC vs. CBD dominance in products:
  • THC-dominant products: CBD-to-THC ratio less than 10:1 1
  • CBD-dominant products: CBD-to-THC ratio greater than 10:1 1
  • Balanced products (1:1 ratio) should be considered THC-dominant 1
• Inform patients that the route of administration affects safety profile, with edible cannabis products potentially causing more emergency department visits due to delayed onset of effects leading to overdosing 1

Potential Therapeutic Applications

• For cancer patients with refractory chemotherapy-induced nausea and vomiting despite optimal prophylaxis, dronabinol, nabilone, or quality-controlled oral 1:1 THC:CBD extract may be considered 1
• For HIV-associated neuropathic pain, some evidence supports cannabis use, though studies have limitations including selection bias 1
• There is insufficient consistent clinical data to recommend cannabinoids to improve taste disorders or anorexia in cancer patients 1
• Clinicians should recommend against use of cannabis/cannabinoids in place of standard medical treatments 1

Potential Adverse Effects and Risks

• Common adverse effects include somnolence, fatigue, dizziness, confusion, nausea, dry mouth, and hypotension 1
• Adverse effects are typically dose-dependent and generally manageable 1
• Elderly patients and those with hepatic impairment may be at higher risk for adverse effects due to reduced drug clearance 2
• Patients with cardiovascular issues should be monitored closely, as THC can affect heart rate and blood pressure 2

Drug Interactions

• THC inhibits several cytochrome P450 enzymes (CYP3A4, CYP2C9, CYP2C19), which could affect metabolism of concurrent medications 2, 6
• Both THC and many medications can cause central nervous system effects that may be additive, including dizziness, confusion, and fatigue 2
• Proton pump inhibitors may cause false positive urine tests for THC; alternative confirmatory methods should be considered 7
• CYP2C9 polymorphisms (present in up to 35% of Caucasians) can increase THC bioavailability 6
• Avoid high-fat meals when taking oral cannabis products, as this significantly increases cannabinoid absorption and may exacerbate drug interactions 2

Special Considerations for Perioperative Use

• For patients with significant cannabis consumption (>1.5g/day inhaled, >300mg/day CBD oil, >20mg/day THC oil, or unknown product >2-3 times/day), special perioperative considerations are needed 1
• If surgery is >7 days away, consider weaning or stopping cannabis 1
• If surgery is <1 day away, do not wean or stop cannabis abruptly 1
• For therapeutic cannabis users, involve the cannabis authorizer in discussions of weaning, dose changes, and substitution 1

Legal and Regulatory Education

• Inform patients that while medical marijuana has been legalized in many states, it remains classified as a Schedule I substance federally 1
• Educate patients on state and federal regulations regarding cannabis use 1
• Variable THC and CBD content in products makes standardization difficult and interactions unpredictable 2