Understanding the Clinical Pharmacology of Marijuana-Tobacco Co-administration

Inclusion Criteria

• Heart rate \< 105 beats per minute (BPM)*
• Systolic Blood Pressure \< 160 and > 90*
• Diastolic Blood Pressure \< 100 and > 50*

*Considered out of range if both machine and manual readings are above/below these thresholds.

• Body Mass Index (BMI) ≤ 38.0 (at investigator's discretion for higher BMI if no other concurrent health issues)
• Current regular user of cannabis who smokes or vapes cannabis or THC extracts at least three days a week for the past 3 months or more
• Test positive for D-9-tetrahydrocannabinol (THC) at screening and self-report of cannabis use
• Current user of inhaled forms of tobacco/nicotine (cigarette, cigars, e-cigarettes) who use the product daily for the past 3 months or more
• Saliva cotinine ≥ 30 ng/mL

Exclusion Criteria

• Unstable medical conditions:

• Heart disease
• Seizures
• Cancer
• Thyroid disease (okay if controlled with medication)
• Diabetes
• Hepatitis B or C or Liver disease
• Glaucoma
• Kidney disease or urinary retention
• An ulcer in the past year
• Active use of an inhaler for asthma or Chronic Obstructive Pulmonary Disease (COPD)
• Hypertension if uncontrolled (meaning participant has a diagnosis, but they are not taking medication/under treatment (e.g., diet or exercise plan)
• Drug/Alcohol Dependence

• Alcohol or illicit drug dependence within the past 12 months (currently in treatment) with the exception of those who recently completed an alcohol/drug treatment program
• Positive toxicology test at the screening visit (THC \& prescribed medications okay)
• Opioid replacement therapy (including methadone, buprenorphine, or other)
• Psychiatric conditions

• Current or past schizophrenia, and/or current or past bipolar disorder
• Major depression, current or within the past year
• Major personality disorder
• Participants with current or past minor or moderate depression and/or anxiety disorders will be reviewed by the PI [study physician] and considered for inclusion
• History of psychiatric hospitalizations are not exclusionary, but study participation will be determined as per PI's [study physician's] approval
• Current regular use of any psychiatric medications with the exception of Selective serotonin reuptake inhibitors (SSRI) and serotonin-norepinephrine reuptake inhibitors (SNRI) and current evaluation by the PI that the participant is otherwise healthy, stable, and able to participate
• Congenital or acquired immunodeficiency disorders (i.e. HIV, congenital immune deficiency syndrome, chronic diseases)
• Other disorders (i.e. ICU, malnutrition, immunosuppressive therapy)
• Traumatic brain injury
• Recent onset or change (worsening) in cough, fever and/or abdominal symptoms (vomiting or pain) in the past two weeks
• Medications

• Use of medications that are inducers of nicotine metabolizing enzyme CYP2A6 (Example: rifampicin, dexamethasone, phenobarbital, and other anticonvulsant drugs)
• Concurrent use of nicotine-containing medications
• Any stimulant medications (ex. Adderall) generally given for attention deficit hyperactivity disorder (ADHD) treatment
• Other/Misc. Chronic Health Problems

• Oral thrush
• Fainting
• Other "life threatening illnesses" as per study physician's discretion
• Pregnancy

• Pregnancy (self-reported and urine pregnancy test)
• Breastfeeding (determined by self-report)
• Concurrent participation in another clinical trial
• Inability to communicate in English
• History of marijuana-induced psychosis or paranoia after smoking marijuana
• Scoring a 7 or higher on the Severity of Dependence Scale (SDS) for cannabis use
• Planning to quit smoking or vaping within the next 60 days
• Planning to quit cannabis use within the next 60 days
• Uncomfortable with getting blood drawn
• Willingness to abstain from tobacco smoking and all combustible products for 13 hours before admission
• Willingness to abstain from smoking/ingestion of cannabis 13 hours before
• Willingness to abstain from nicotine products 13 hours before each admission