Effects of THC on pain in older adults

Pharmacokinetics and Pharmacodynamics of Oral and Vaporized Delta-9-Tetrahydrocannabinol (THC) in Older Adults

Early Phase 1 Interventional Yale University · NCT05906511

This study is testing whether THC can help relieve pain in older adults by comparing its effects from both oral and vaporized forms.

Quick facts

PhaseEarly Phase 1
Study typeInterventional
Enrollment20 (estimated)
Ages65 Years and up
SexAll
SponsorYale University Academic / other
Locations1 site (West Haven, Connecticut)
Trial IDNCT05906511 on ClinicalTrials.gov

What this trial studies

This double-blind, placebo-controlled, crossover study aims to evaluate the pharmacokinetic and pharmacodynamic effects of delta-9 tetrahydrocannabinol (THC) in older adults, who are increasingly using cannabis for pain relief. The study consists of two sub-studies: one focusing on oral THC administration and the other on vaporized THC. Each sub-study will involve 20 participants aged 65 and older, who will receive different doses of THC or placebo across multiple test sessions. Blood samples will be collected to assess THC levels and its effects on pain sensitivity, while also evaluating potential abuse liability and adverse effects.

Who should consider this trial

Good fit: Ideal candidates are healthy men and women aged 65 years or older with prior exposure to THC or cannabis.

Not a fit: Patients with current psychiatric or substance use disorders, or those with significant medical conditions affecting respiratory health, may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide insights into effective pain management strategies for older adults using THC.

How similar studies have performed: While studies on THC's effects exist, this specific focus on older adults and the comparison of oral versus vaporized forms is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. Healthy male and female participants aged 65 ≥ years old
2. Prior exposure to THC or cannabis least once in the last 10 years; 1-10 times in the last 20 years; or more than 20 times in their lifetime
3. Capable of providing informed consent in English.

Exclusion Criteria:

1. Meeting DSM-5 criteria for psychiatric/substance use disorders (SUD) other than tobacco use disorder, within the last year
2. Current use of cannabinoid products, as evidenced by a urine drug screen
3. Having a history of treatment for cannabis use disorder
4. History of intent or current intent of abstaining from cannabis use
5. Clinically significant medical disorders (e.g. liver/kidney dysfunction, immunosuppressing conditions, history or presence of epilepsy, seizures, head trauma with loss of consciousness)
6. Medical conditions that increase the risk of respiratory problems (e.g. COPD, asthma, recuring bronchitis, reactive airway disorder)\* (does not apply to the Oral THC Sub-Study)
7. History of environmental sensitivities (e.g. bronchospastic allergies, multiple chemical sensitivities) or other airway sensitivities that require the use of an epi pen\*(does not apply to the Oral THC Sub-Study)
8. Neurological conditions that may change the response to nociceptive stimuli (e.g., stroke, neuropathy), or that lead to loss of balance, evidenced by a neuro-sensory exam
9. Contraindications for exposure to nociceptive stimuli, such as untreated hypertension
10. Current regular use of drugs known to affect pain, or that are prominent inducers or inhibitors of CYP2C9, CYP3A4, or UGTA19 (e.g., carbamazepine, valproate, fluvoxamine, and paroxetine)
11. Major neurocognitive disorders precluding participation, evidenced by a clinical exam
12. Abnormal EKG, arrythmia, vasospastic disease, chronic heart failure, or presence of a pacemaker
13. Elevation of liver enzymes (ALT, AST) 2x the normal limit or higher
14. Personal or family history of primary psychotic disorders, or mood disorders with psychotic features
15. Current suicidal ideation
16. Allergy or serious adverse reactions to sesame oil, THC, or cannabis
17. Having received any drug as part of a research study within 30 days prior to receiving the study medication in the current study.

Where this trial is running

West Haven, Connecticut

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Pain, ToleranceOral vs Vaporized THCAbuse LiabilityPharmacokinetics THCPharmacodynamics THC
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.