Human Perception of Odors and Odor Blockers

Tobacco Smoking Clinical Trial

Official title:

Human Perception of Odors and Odor Blockers

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT06191419
• Other study ID #: 43123
• Secondary ID: 1K18DC020155
• Status: Recruiting
• Phase: N/A
• Start date: April 5, 2024
• Est. completion date: March 2025

Study information

• Verified date: April 2024
• Source: University of Kentucky
• Contact: Timothy McClintock, PhD
• Phone: 8593231083
• Email: mcclint[@]uky.edu
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The goal of this clinical trial is to determine whether blockers of perception of key odorants in cigarette smoke have any utility in smoking cessation. The main question it aims to answer is:

• Can odor blockers be used to suppress perception of the intensity of cigarette smoke in ways that reduce the ability of the odor of cigarette smoke to increase the urge to smoke.

Participants will be asked to smell up to 20 odor samples per session and report on odor pleasantness and desire to smoke.

Description:

The experimental treatments include controls (clean air, irrelevant odor), blocking odors, cigarette smoke odor, and cigarette smoke odor mixed with blocking odors or irrelevant odor. To obtain cigarette smoke odor a 1 inch length of a 1R6F research cigarette is burned to completion in a sealed 5 gallon chamber fitted with septa. Using a syringe fit with a needle and filter, 60 mL aliquots of smoke odor are obtained. These smoke odor aliquots, along with blocking odors, are injected into odor sample bags fit with a septum and a valve that can be attached to the CPAP nose mask worn by each participating smoker. Participants open the valve, inhale once through the nose, close the valve, and then remove the bag from the mask before reporting odor pleasantness and the desire to smoke. A 2 - 3 min wait period is enforced between each odor presentation to prevent odor adaptation and to allow acute motivational effects to subside.

In a testing session a participant sniffs 4 concentrations of a mixture of 2 blocking odors, along with control odor samples. Presentation order is randomized. Each participant is assigned their own CPAP nose mask, and masks are disinfected after use. Participants also provide demographic (age, sex, ethnic and racial background) and smoking history information (cigarettes per day, preferred brand, age at onset, and time since last cigarette).

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 40
• Est. completion date: March 2025
• Est. primary completion date: December 2024
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 60 Years

Eligibility

Inclusion Criteria:

• Smoker

Exclusion Criteria:

• Non Smoker

• Self reported inability to smell or taste

Related Conditions & MeSH terms

• Smoking Behaviors
• Tobacco Smoking

Intervention

Other:
• Odorants
Each smoker is assigned a CPAP nose mask. Odor sample bags are attached to the mask. Smokers open the valve, inhale once through the nose, close the valve, remove the bag from the mask and report on the odor.

Locations

Country	Name	City	State
United States	University of Kentucky	Lexington	Kentucky

Sponsors (2)

Lead Sponsor	Collaborator
Tim McClintock	National Institute on Deafness and Other Communication Disorders (NIDCD)

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Cigarette Purchase Task	The Cigarette Purchase Task (Strickland et al., 2016) requires selecting how much the smoker is willing to spend for a single cigarette (their preferred brand) from a list of 19 amounts ranging from $0.00 (free) to $1,120.	3 hours (total for all outcome measures)
Primary	Desire to Smoke	A rating of participant's desire to smoke on a scale of 0 - 100, where a higher score indicates increased desire.	3 hours (total for all outcome measures)
Secondary	Odor pleasantness score	Participants complete a forced choice test by scoring whether the odor is pleasant or unpleasant	3 hours (total for all outcome measures)