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NCT Number: NCT07694466

Lung Health and Breath Biomarkers: Acute Effects of Inhaled Cannabis

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

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Key information

Age range

18 year–55 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Early Phase 1

Primary location

University of Kentucky

Lexington, Kentucky, 40508, United States

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • English-speaking,
  • Literate adults,
  • Male or female,
  • Between the ages of 18 and 55,
  • Body Mass Index from 18.5 and 32.0 kg/m2,
  • Able to provide written informed consent and perform all study procedures,
  • 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,
  • Past year history of vaporized or smoked cannabis use to intoxication,
  • Past 30-day use of combusted tobacco,
  • Not currently seeking treatment for cannabis, tobacco cigarettes, or other drug use,
  • If female, a negative pregnancy test and use of an effective form of contraception during study participation (e.g., oral contraceptive, abstinence, barrier method),
  • Negative urine drug test for drugs of abuse (other than cannabis) before every Laboratory Session, and
  • 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

  • Physiologic drug dependence on opioids, benzodiazepines, barbiturates, and/or alcohol that would require medical management,
  • 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]),
  • Existing or significant lung health problems that could interfere with the study,
  • Current or history of major psychiatric disorder that would limit the participant's ability to participate in the study (e.g., bipolar disorder),
  • Exclusive use of tobacco or cannabis through vapes and Electronic Nicotine Delivery Systems (ENDS) products,
  • Currently using daily prescription medications to manage medical conditions or any drug that could interfere with the study (as determined by the study physician),
  • Clinically significant abnormal ECG (as determined by study physician/cardiologist),
  • Clinically significant abnormal laboratory findings (e.g., liver function tests greater than 3x the upper limits of normal range),
  • History of seizure disorder,
  • Clinically significant history of head injuries requiring medical management or long-lasting sequelae.

Treatment and study plan

Cannabis (THC)

Drug

Active Cannabis (THC) will be inhaled.

Tobacco Cigarette

Drug

A leading brand of tobacco cigarette (~1.0 gram; Marlboro Gold; Phillip Morris International)

Primary outcomes

  1. Exhaled Breath Condensate (EBC)

    Time frame: Baseline (prior to study drug admission), approximately 25, 40,60, 90, 120 and 180 minutes after drug administration

    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.

  2. Breath Volatile Organic Compound (BVOC)

    Time frame: Baseline (prior to study drug admission), approximately 25, 40,60, 90, 120 and 180 minutes after drug administration

    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.

  3. Exhaled Nitric Oxide (FeNO)

    Time frame: Baseline (prior to study drug admission), approximately 25, 40,60, 90, 120 and 180 minutes after drug administration

    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.

Secondary outcomes

  1. Cigarette Evaluation Questionnaire (CEQ)

    Time frame: Immediately following administration of combusted tobacco or cannabis cigarette (approximately 10 minutes after drug administration)

    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.

  2. Modified Cigarette Evaluation Questionnaire (mCEQ)

    Time frame: Immediately following administration of vaporized cannabis (approximately 10 minutes after drug administration)

    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.

Study contacts

Contact information is provided by the study sponsor or research team.

Paul A Nuzzo, M.A.

CONTACT

[email protected]

859-323-0002

Sponsors and collaborators

Lead sponsor

Hannah Harris

Other

Registry information

Official study title

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

Important dates

Study start
2026
Primary completion
2027
Study completion
2027
First posted
Jul 10, 2026
Registry last updated
Jul 10, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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