Lung Health and Breath Biomarkers: Acute Effects of Inhaled Cannabis

Lung Health and Breath Biomarkers: Acute Effects of Combusted and Vaporized Cannabis Inhalation Compared to Tobacco Cigarette Combustion in the Human Laboratory

This outpatient study examines how inhaled cannabis, combustible or vaporized, alters lung health and breath biomarkers compared to a tobacco cigarette.

Study Overview

• Status: Not yet recruiting
• Conditions: Biomarkers; Cannabis Use; Tobacco
• Intervention / Treatment: Drug: Tobacco Cigarette; Drug: Cannabis (THC)

• Study Type: Interventional
• Enrollment (Estimated): 12
• Phase: Early Phase 1

Contacts and Locations

• Study Contact: Name: Paul A Nuzzo, M.A.; Phone Number: 859-323-0002; Email: pnuzz2@email.uky.edu

Study Locations

• United States
  • Kentucky
    • Lexington, Kentucky, United States, 40508
      • University Of Kentucky

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

1. English-speaking,
2. Literate adults,
3. Male or female,
4. Between the ages of 18 and 55,
5. Body Mass Index from 18.5 and 32.0 kg/m2,
6. Able to provide written informed consent and perform all study procedures,
7. Current recreational cannabis users - must report past 30-day cannabis use and at least 5 exposures in the past year (minimum use criteria); no limit on maximum use,
8. Past year history of vaporized or smoked cannabis use to intoxication,
9. Past 30-day use of combusted tobacco,
10. Not currently seeking treatment for cannabis, tobacco cigarettes, or other drug use,
11. If female, a negative pregnancy test and use of an effective form of contraception during study participation (e.g., oral contraceptive, abstinence, barrier method),
12. Negative urine drug test for drugs of abuse (other than cannabis) before every Laboratory Session, and
13. Otherwise, healthy as determined by the investigator based on medical history, physical examination, vital signs, laboratory chemistries (blood chemistry with liver function tests and hematology, urinalysis, and microscopic evaluation, 12-lead electrocardiogram).

Exclusion Criteria:

1. Physiologic drug dependence on opioids, benzodiazepines, barbiturates, and/or alcohol that would require medical management,
2. Clinically significant acute medical problem (e.g., infection) or chronic medical problem requiring daily medication or ongoing medical care (e.g., hypertension, cardiovascular disease, diabetes, respiratory disorders [e.g., asthma, COPD]),
3. Existing or significant lung health problems that could interfere with the study,
4. Current or history of major psychiatric disorder that would limit the participant's ability to participate in the study (e.g., bipolar disorder),
5. Exclusive use of tobacco or cannabis through vapes and Electronic Nicotine Delivery Systems (ENDS) products,
6. Currently using daily prescription medications to manage medical conditions or any drug that could interfere with the study (as determined by the study physician),
7. Clinically significant abnormal ECG (as determined by study physician/cardiologist),
8. Clinically significant abnormal laboratory findings (e.g., liver function tests greater than 3x the upper limits of normal range),
9. History of seizure disorder,
10. Clinically significant history of head injuries requiring medical management or long-lasting sequelae.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Tobacco Cigarette; Participants will inhale a leading brand of tobacco cigarette (~1.0 gram; Marlboro Gold; Phillip Morris International).	Drug: Tobacco Cigarette; A leading brand of tobacco cigarette (~1.0 gram; Marlboro Gold; Phillip Morris International)
Experimental: Vaporized Cannabis (THC); Participants will receive a non-therapeutic, active vaporized marijuana.	Drug: Cannabis (THC); Active Cannabis (THC) will be inhaled.
Experimental: Combustible Cannabis (THC); Participants will receive a non-therapeutic, active smoked marijuana.	Drug: Cannabis (THC); Active Cannabis (THC) will be inhaled.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Exhaled Breath Condensate (EBC)	To capture Exhaled Breath Condensate (EBC) samples, the participant will inhale and exhale normally through an RTube device for ~10 minutes. The RTube will separate saliva from the main exhaled stream in the blue "Tee" section of the mouthpiece. The exhaled stream passes through a one-way duckbill valve into a gray condensation tube. Samples can be analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The primary outcome of this measure is the identification of metals, proteins, as well as non-volatiles present before and after drug administration conditions.	Baseline (prior to study drug admission), approximately 25, 40,60, 90, 120 and 180 minutes after drug administration
Breath Volatile Organic Compound (BVOC)	For this test, participants will place the ReCIVA Breath Sampler device over their nose and mouth for ~15 minutes and breathe normally. Exhaled breath volatile organic compounds (BVOC) are collected on Breath Biopsy Cartridges and can be analyzed using Thermal Desorption-Gas Chromatography-Mass Spectrometry (TD-GC-MS) to identify over 200 volatile organic compound (VOC) biomarkers. The primary outcome of this measure is the identification of BVOC biomarkers present before and after drug administration conditions.	Baseline (prior to study drug admission), approximately 25, 40,60, 90, 120 and 180 minutes after drug administration
Exhaled Nitric Oxide (FeNO)	Elevated FeNO levels serve as a biomarker for airway inflammation. To measure this, the NIOX VERO FeNO device will be used. Participants will insert the NIOX mouthpiece into their mouth and be instructed to inhale through the device and, when prompted, exhale for ~10 seconds. The primary outcome of this measure is the level of FeNO present before and after drug administration conditions.	Baseline (prior to study drug admission), approximately 25, 40,60, 90, 120 and 180 minutes after drug administration

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cigarette Evaluation Questionnaire (CEQ)	Immediately following drug administration of tobacco or cannabis cigarettes, participants are to rate each cigarette on a scale from 0 'Not at all' to 7- 'Extremely' for questions on satisfaction, similarity to usual brand, psychological reward, aversion, enjoyment of respiratory sensations, and perceived strength.	Immediately following administration of combusted tobacco or cannabis cigarette (approximately 10 minutes after drug administration)
Modified Cigarette Evaluation Questionnaire (mCEQ)	Immediately following drug administration of vaped cannabis, each participant will rate vaped cannabis on a 7-point response scale of 0 - 'Not at all' to 7- 'Extremely' for questions on satisfaction, similarity to usual brand, psychological reward, aversion, and enjoyment of respiratory sensations.	Immediately following administration of vaporized cannabis (approximately 10 minutes after drug administration)

Collaborators and Investigators

• Sponsor: Hannah Harris
• Investigators: Principal Investigator: Hannah M Harris, Ph.D., University Of Kentucky

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): February 1, 2027
• Study Completion (Estimated): June 1, 2027

Study Registration Dates

• First Submitted: June 22, 2026
• First Submitted That Met QC Criteria: July 6, 2026
• First Posted (Actual): July 10, 2026

Study Record Updates

• Last Update Posted (Actual): July 10, 2026
• Last Update Submitted That Met QC Criteria: July 6, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: cannabis; tobacco; vaping
• Additional Relevant MeSH Terms: Mental Disorders; Substance-Related Disorders; Chemically-Induced Disorders; Behavior; Smoking; Marijuana Abuse; Vaping; Organic Chemicals; Hydrocarbons; Terpenes; Cannabinoids; Dronabinol; nabiximols
• Other Study ID Numbers: 111900

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No