Impact of Cannabis on Pain and Inflammation Among Patients With Rheumatoid or Psoriatic Arthritis

This laboratory study will investigate the impact of cannabis on pain, affect, and inflammation among patients with rheumatoid or psoriatic arthritis (n = 76). Two cannabis formulations varying in potency will be administered via vaporization across two experimental sessions using a counter-balanced, double-blind, crossover design.

This laboratory study will investigate the impact of cannabis on pain, affect, and inflammation among patients with rheumatoid or psoriatic arthritis (n = 76). Two cannabis formulations varying in potency will be administered via vaporization across two experimental sessions using a counter-balanced, double-blind, crossover design. Blood will be collected during each session (pre-vaporization, 10 minutes post-vaporization, 60 minutes post-vaporization). Self-reported pain and affect will be assessed at the same time points. The effect of cannabis on pain, affect, and inflammatory biomarkers will be assessed. The study will recruit 76 patients to obtain a final sample of 66 with complete data (15% attrition). This study will be the first to investigate the effect of cannabis on pain, affect, and markers of inflammation among patients with rheumatoid or psoriatic arthritis. This study has the potential to guide clinical decisions pertaining to use of cannabis to treat arthritis symptoms with more precise recommendations regarding cannabis formulation.

Eligibility Criteria:
Inclusion Criteria:

1. current RA or PA diagnosis with active arthritis not adequately controlled by standard medication
2. if taking prescribed steroid, non-steroidal anti-inflammatory (NSAID), and/or disease-modifying anti-rheumatic drug (DMARDS; e.g., tumor necrosis factor inhibitors), must be stable use for at least 1 month prior to enrollment (all must be maintained throughout the study)
3. English-speaking or Spanish-speaking
4. negative urine toxicology screen
5. negative pregnancy test
6. not nursing
7. use of highly effective birth control during the study for both males and females
8. prior history of vaping or smoking cannabis

   Exclusion Criteria:
9. greater than zero breath alcohol concentration
10. presence of psychosis, panic disorder, or suicidal ideation or intent
11. self-report of serious adverse reaction to cannabis in the past year
12. smoking more than 20 tobacco cigarettes per day
13. body mass index below 18.0 or above 33.0 kg/m2 range confirmed during medical exam
14. all current asthma conditions (i.e., active symptomatic asthma within the last week) or current or past history of asthma triggered by smoking or vaping
15. current diagnosis of dementia or Parkinson's disease
16. below cut-off on mental status exam
17. current diagnosis of moderate to severe traumatic brain injury
18. current diagnosis of epilepsy
19. individuals who are immunocompromised (i.e., post-organ transplant, those with an immune deficiency disorder such as HIV, individuals taking immunosuppressant steroids such as continuous prednisone use, and those with lupus)
20. past kidney disease (e.g., glomerular nephritis, polycystic kidney disease) and/or presence of elevated creatinine
21. cardiac disease confirmed via clinically significant abnormal findings on an EKG (e.g., arrhythmia, conduction abnormalities, ischemia, or evidence of past myocardial infarction), as well as diagnoses of congestive heart failure or cardiomyopathy
22. abnormal vital signs
23. taking any exclusionary medications
24. presence of any severe cardiovascular, renal, or hepatic disorder
25. below 18 or above 65 years of age
26. use of cannabis in the past 1 month before commencement of study participation and throughout the study as confirmed via urine toxicology screening aa) below minimum self-reported pain level on a visual analog scale (VAS) pre-study enrollment via telephone and at baseline due to potential variability in pain level