Trial Outcomes & Findings for Combining Varenicline and Guanfacine for Smoking Cessation (NCT NCT04198116)
NCT ID: NCT04198116
Last Updated: 2026-06-09
Results Overview
Latency (in minutes) to time of first cigarette smoked during the 50-minute delay period.
Recruitment status
COMPLETED
Study phase
PHASE2
Target enrollment
167 participants
Primary outcome timeframe
minutes (range 0 to 50 min)
Results posted on
2026-06-09
Participant Flow
We consented 167 participants, and of these 68 met exclusion criteria (i.e., medical contraindications), 25 failed to complete eligibility screening, and 10 failed to meet inclusion criteria (i.e, smoking amount). We randomized 64 to medication.
Participant milestones
| Measure |
Varenicline + Guanfacine ER
Varenicline (2mg/day) + Guanfacine extended release (6mg/day ER). Varenicline (2mg/day) administered orally twice a day at 8:00 AM and 8:00 PM while titrating to full dose. Titration schedule: Days 1-9 0mg/day; 0mg/dose, Days 10-12 0.5mg/day; 0.5mg/dose 8:00 PM, Days 13-15 1mg/day; 0.5mg/dose, Days 16-21 2mg/day; 1mg/dose. Guanfacine ER (6mg/day) administered orally twice daily at 8:00 AM and 8:00 PM while titrating to the full dose. Titration schedule: Days 1-3 1mg/day; 0.5mg/dose, Days 4-6 2mg/day; 1mg/dose, Days 7-9 3mg/day; 1.5mg/dose, Days 10-12 4mg/day; 2mg/dose; Days 13-15 5mg/day; 2.5mg/dose and Days 16-23 6mg/day; 3mg/dose. Once at steady state, administration is orally once per day at 8:00 PM for both medications.
Varenicline: Varenicline 2mg/day
Guanfacine ER: Guanfacine Extended Release (6mg/day ER)
|
Varenicline
Varenicline (2mg/day). Varenicline (2mg/day) administered orally twice a day at 8:00 AM and 8:00 PM while titrating to full dose. Titration schedule: Days 1-9 0mg/day; 0mg/dose, Days 10-12 0.5mg/day; 0.5mg/dose 8:00 PM, Days 13-15 1mg/day; 0.5mg/dose, Days 16-21 2mg/day; 1mg/dose. Once at steady state, administration is orally once per day at 8:00 PM.
Varenicline: Varenicline 2mg/day
|
|---|---|---|
|
Overall Study
STARTED
|
32
|
32
|
|
Overall Study
COMPLETED
|
27
|
23
|
|
Overall Study
NOT COMPLETED
|
5
|
9
|
Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
Combining Varenicline and Guanfacine for Smoking Cessation
Baseline characteristics by cohort
| Measure |
Varenicline + Guanfacine ER
n=32 Participants
Varenicline (2mg/day) + Guanfacine extended release (6mg/day ER). Varenicline (2mg/day) administered orally twice a day at 8:00 AM and 8:00 PM while titrating to full dose. Titration schedule: Days 1-9 0mg/day; 0mg/dose, Days 10-12 0.5mg/day; 0.5mg/dose 8:00 PM, Days 13-15 1mg/day; 0.5mg/dose, Days 16-21 2mg/day; 1mg/dose. Guanfacine ER (6mg/day) administered orally twice daily at 8:00 AM and 8:00 PM while titrating to the full dose. Titration schedule: Days 1-3 1mg/day; 0.5mg/dose, Days 4-6 2mg/day; 1mg/dose, Days 7-9 3mg/day; 1.5mg/dose, Days 10-12 4mg/day; 2mg/dose; Days 13-15 5mg/day; 2.5mg/dose and Days 16-23 6mg/day; 3mg/dose. Once at steady state, administration is orally once per day at 8:00 PM for both medications.
Varenicline: Varenicline 2mg/day
Guanfacine ER: Guanfacine Extended Release (6mg/day ER)
|
Varenicline
n=32 Participants
Varenicline (2mg/day). Varenicline (2mg/day) administered orally twice a day at 8:00 AM and 8:00 PM while titrating to full dose. Titration schedule: Days 1-9 0mg/day; 0mg/dose, Days 10-12 0.5mg/day; 0.5mg/dose 8:00 PM, Days 13-15 1mg/day; 0.5mg/dose, Days 16-21 2mg/day; 1mg/dose. Once at steady state, administration is orally once per day at 8:00 PM.
Varenicline: Varenicline 2mg/day
|
Total
n=64 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Continuous
|
44.00 years
STANDARD_DEVIATION 11.46 • n=20 Participants
|
45.00 years
STANDARD_DEVIATION 11.05 • n=20 Participants
|
44.5 years
STANDARD_DEVIATION 11.23 • n=40 Participants
|
|
Sex: Female, Male
Female
|
12 Participants
n=20 Participants
|
13 Participants
n=20 Participants
|
25 Participants
n=40 Participants
|
|
Sex: Female, Male
Male
|
20 Participants
n=20 Participants
|
19 Participants
n=20 Participants
|
39 Participants
n=40 Participants
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
|
5 Participants
n=20 Participants
|
1 Participants
n=20 Participants
|
6 Participants
n=40 Participants
|
|
Ethnicity (NIH/OMB)
Not Hispanic or Latino
|
27 Participants
n=20 Participants
|
31 Participants
n=20 Participants
|
58 Participants
n=40 Participants
|
|
Ethnicity (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=20 Participants
|
0 Participants
n=20 Participants
|
0 Participants
n=40 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=20 Participants
|
0 Participants
n=20 Participants
|
0 Participants
n=40 Participants
|
|
Race (NIH/OMB)
Asian
|
0 Participants
n=20 Participants
|
1 Participants
n=20 Participants
|
1 Participants
n=40 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=20 Participants
|
0 Participants
n=20 Participants
|
0 Participants
n=40 Participants
|
|
Race (NIH/OMB)
Black or African American
|
9 Participants
n=20 Participants
|
11 Participants
n=20 Participants
|
20 Participants
n=40 Participants
|
|
Race (NIH/OMB)
White
|
23 Participants
n=20 Participants
|
20 Participants
n=20 Participants
|
43 Participants
n=40 Participants
|
|
Race (NIH/OMB)
More than one race
|
0 Participants
n=20 Participants
|
0 Participants
n=20 Participants
|
0 Participants
n=40 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=20 Participants
|
0 Participants
n=20 Participants
|
0 Participants
n=40 Participants
|
|
Region of Enrollment
United States
|
32 participants
n=20 Participants
|
32 participants
n=20 Participants
|
64 participants
n=40 Participants
|
|
Number of cigarettes per day
|
14.61 Number of cigarettes per day
STANDARD_DEVIATION 6.10 • n=20 Participants
|
14.66 Number of cigarettes per day
STANDARD_DEVIATION 5.81 • n=20 Participants
|
14.64 Number of cigarettes per day
STANDARD_DEVIATION 5.96 • n=40 Participants
|
PRIMARY outcome
Timeframe: minutes (range 0 to 50 min)Population: Participants who completed laboratory session.
Latency (in minutes) to time of first cigarette smoked during the 50-minute delay period.
Outcome measures
| Measure |
Varenicline + Guanfacine ER
n=27 Participants
Varenicline (2mg/day) + Guanfacine extended release (6mg/day ER). Varenicline (2mg/day) administered orally twice a day at 8:00 AM and 8:00 PM while titrating to full dose. Titration schedule: Days 1-9 0mg/day; 0mg/dose, Days 10-12 0.5mg/day; 0.5mg/dose 8:00 PM, Days 13-15 1mg/day; 0.5mg/dose, Days 16-21 2mg/day; 1mg/dose. Guanfacine ER (6mg/day) administered orally twice daily at 8:00 AM and 8:00 PM while titrating to the full dose. Titration schedule: Days 1-3 1mg/day; 0.5mg/dose, Days 4-6 2mg/day; 1mg/dose, Days 7-9 3mg/day; 1.5mg/dose, Days 10-12 4mg/day; 2mg/dose; Days 13-15 5mg/day; 2.5mg/dose and Days 16-23 6mg/day; 3mg/dose. Once at steady state, administration is orally once per day at 8:00 PM for both medications.
Varenicline: Varenicline 2mg/day
Guanfacine ER: Guanfacine Extended Release (6mg/day ER)
|
Varenicline
n=23 Participants
Varenicline (2mg/day). Varenicline (2mg/day) administered orally twice a day at 8:00 AM and 8:00 PM while titrating to full dose. Titration schedule: Days 1-9 0mg/day; 0mg/dose, Days 10-12 0.5mg/day; 0.5mg/dose 8:00 PM, Days 13-15 1mg/day; 0.5mg/dose, Days 16-21 2mg/day; 1mg/dose. Once at steady state, administration is orally once per day at 8:00 PM.
Varenicline: Varenicline 2mg/day
|
|---|---|---|
|
Latency
|
39.81 minutes
Standard Deviation 17.4
|
37.57 minutes
Standard Deviation 19.88
|
Adverse Events
Varenicline + Guanfacine ER
Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths
Varenicline
Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths
Serious adverse events
Adverse event data not reported
Other adverse events
Adverse event data not reported
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place