Trial Outcomes & Findings for A Trial of Guanfacine-er for Cannabis Use Disorder (NCT NCT05273567)

Last Updated: 2026-08-18

Results Overview

Change in quartiles of use as compared to baseline. Participants will complete ecological momentary assessments (EMA) daily on any internet-accessible device (smart phone, computer, tablet). The daily EMA will assess cannabis use during quartiles of the day. Participants will mark "Yes" if they used cannabis from 12AM-6AM, 6AM-12PM, 12PM-6PM, or 6PM-12AM for each 24 hour period of the study.

Recruitment status

COMPLETED

Study phase

PHASE2

Target enrollment

22 participants

Primary outcome timeframe

12 weeks of study

Results posted on

2026-08-18

Participant Flow

Participant milestones

Participant milestones
Measure	Guanfacine-ER Participants will start on guanfacine-ER 1mg nightly for 1-week (week 1) and slowly increase by 1mg/per week to a max dose of 4mg per day or maximum dose as tolerated. Medication taper to discontinuation will begin in week 11 and continue into week 12 until complete by end of study, decreasing the dose by 1mg every 4 days until stopped. guanfacine-ER: guanfacine-er dispensed daily, starting at 1mg and increasing to 4mg/day or the maximum tolerated dose.	Placebo Placebo will be taken nightly and titrated and tapered similar to the active arm. Placebo: placebo will be dispensed similar to the active arm.
Overall Study STARTED	11	11
Overall Study COMPLETED	4	5
Overall Study NOT COMPLETED	7	6

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

A Trial of Guanfacine-er for Cannabis Use Disorder

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Guanfacine-ER n=11 Participants Participants will start on guanfacine-ER 1mg nightly for 1-week (week 1) and slowly increase by 1mg/per week to a max dose of 4mg per day or maximum dose as tolerated. Medication taper to discontinuation will begin in week 11 and continue into week 12 until complete by end of study, decreasing the dose by 1mg every 4 days until stopped. guanfacine-ER: guanfacine-er dispensed daily, starting at 1mg and increasing to 4mg/day or the maximum tolerated dose.	Placebo n=11 Participants Placebo will be taken nightly and titrated and tapered similar to the active arm. Placebo: placebo will be dispensed similar to the active arm.	Total n=22 Participants Total of all reporting groups
Age, Continuous	40.45 years STANDARD_DEVIATION 7.30 • n=298 Participants	30.18 years STANDARD_DEVIATION 10.48 • n=102 Participants	37.32 years STANDARD_DEVIATION 9.38 • n=400 Participants
Sex: Female, Male Female	4 Participants n=298 Participants	1 Participants n=102 Participants	5 Participants n=400 Participants
Sex: Female, Male Male	7 Participants n=298 Participants	10 Participants n=102 Participants	17 Participants n=400 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	1 Participants n=298 Participants	2 Participants n=102 Participants	3 Participants n=400 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	10 Participants n=298 Participants	9 Participants n=102 Participants	19 Participants n=400 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=298 Participants	0 Participants n=102 Participants	0 Participants n=400 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=298 Participants	0 Participants n=102 Participants	0 Participants n=400 Participants
Race (NIH/OMB) Asian	1 Participants n=298 Participants	0 Participants n=102 Participants	1 Participants n=400 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=298 Participants	0 Participants n=102 Participants	0 Participants n=400 Participants
Race (NIH/OMB) Black or African American	2 Participants n=298 Participants	3 Participants n=102 Participants	5 Participants n=400 Participants
Race (NIH/OMB) White	6 Participants n=298 Participants	6 Participants n=102 Participants	12 Participants n=400 Participants
Race (NIH/OMB) More than one race	1 Participants n=298 Participants	2 Participants n=102 Participants	3 Participants n=400 Participants
Race (NIH/OMB) Unknown or Not Reported	1 Participants n=298 Participants	0 Participants n=102 Participants	1 Participants n=400 Participants

PRIMARY outcome

Timeframe: 12 weeks of study

Population: The analysis population included subjects who entered the study and had available Week 12 outcome data. A total of 22 subjects entered the study: 11 in the treatment group and 11 in the placebo group. At Week 12, 4 subjects in each group remained in the study and contributed data to the outcome analysis. Cannabis use was summarized separately for each daily time quartile as the percentage of days with cannabis use during that time quartile.

Outcome measures

Outcome measures
Measure	Guanfacine-ER n=4 Participants Participants will start on guanfacine-ER 1mg nightly for 1-week (week 1) and slowly increase by 1mg/per week to a max dose of 4mg per day or maximum dose as tolerated. Medication taper to discontinuation will begin in week 11 and continue into week 12 until complete by end of study, decreasing the dose by 1mg every 4 days until stopped. guanfacine-ER: guanfacine-er dispensed daily, starting at 1mg and increasing to 4mg/day or the maximum tolerated dose.	Placebo n=4 Participants Placebo will be taken nightly and titrated and tapered similar to the active arm. Placebo: placebo will be dispensed similar to the active arm.
Change in Cannabis Use as Measured by Ecological Momentary Assessments (EMA). Quartile 1: 12:00 AM - 5:59 AM	-21 percent change in days with cannabis use Standard Deviation 42	13 percent change in days with cannabis use Standard Deviation 25
Change in Cannabis Use as Measured by Ecological Momentary Assessments (EMA). Quartile 2: 6:00 AM - 11:59 AM	-21 percent change in days with cannabis use Standard Deviation 42	-10 percent change in days with cannabis use Standard Deviation 36
Change in Cannabis Use as Measured by Ecological Momentary Assessments (EMA). Quartile 3: 12:00 PM - 5:59 PM	-28 percent change in days with cannabis use Standard Deviation 37	33 percent change in days with cannabis use Standard Deviation 71
Change in Cannabis Use as Measured by Ecological Momentary Assessments (EMA). Quartile 4: 6:00 PM - 11:59 PM	-21 percent change in days with cannabis use Standard Deviation 76	8 percent change in days with cannabis use Standard Deviation 24

Adverse Events

Guanfacine-ER

Serious events: 0 serious events

Other events: 10 other events

Deaths: 0 deaths

Placebo

Serious events: 0 serious events

Other events: 9 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Additional Information

Daniel Brooks

NYSPI

Phone: (917) 861-1270

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place

Measure	Guanfacine-ER n=11 participants at risk Participants will start on guanfacine-ER 1mg nightly for 1-week (week 1) and slowly increase by 1mg/per week to a max dose of 4mg per day or maximum dose as tolerated. Medication taper to discontinuation will begin in week 11 and continue into week 12 until complete by end of study, decreasing the dose by 1mg every 4 days until stopped. guanfacine-ER: guanfacine-er dispensed daily, starting at 1mg and increasing to 4mg/day or the maximum tolerated dose.	Placebo n=11 participants at risk Placebo will be taken nightly and titrated and tapered similar to the active arm. Placebo: placebo will be dispensed similar to the active arm.
Renal and urinary disorders urinary frequency	0.00% 0/11 • Data collected over 12 weeks of study.	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.
General disorders "weird" dreams	0.00% 0/11 • Data collected over 12 weeks of study.	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.
General disorders irritability	0.00% 0/11 • Data collected over 12 weeks of study.	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.
General disorders presyncope	0.00% 0/11 • Data collected over 12 weeks of study.	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.
General disorders sleep difficulties	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.	0.00% 0/11 • Data collected over 12 weeks of study.
Psychiatric disorders suicidality, no plan or intent	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.	0.00% 0/11 • Data collected over 12 weeks of study.
General disorders lightheadedness	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.	0.00% 0/11 • Data collected over 12 weeks of study.
Psychiatric disorders depersonalization	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.	0.00% 0/11 • Data collected over 12 weeks of study.
Respiratory, thoracic and mediastinal disorders congestion	0.00% 0/11 • Data collected over 12 weeks of study.	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.
Musculoskeletal and connective tissue disorders body aches	0.00% 0/11 • Data collected over 12 weeks of study.	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.
General disorders "wooziness" in legs	0.00% 0/11 • Data collected over 12 weeks of study.	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.
Respiratory, thoracic and mediastinal disorders dyspnea on exertion	0.00% 0/11 • Data collected over 12 weeks of study.	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.
General disorders throat irritation	0.00% 0/11 • Data collected over 12 weeks of study.	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.
Gastrointestinal disorders bloating	0.00% 0/11 • Data collected over 12 weeks of study.	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.
General disorders sedation	0.00% 0/11 • Data collected over 12 weeks of study.	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.
Psychiatric disorders passive SI	0.00% 0/11 • Data collected over 12 weeks of study.	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.
Cardiac disorders increased diastolic BP	0.00% 0/11 • Data collected over 12 weeks of study.	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.
Metabolism and nutrition disorders increased appetite	0.00% 0/11 • Data collected over 12 weeks of study.	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.
Metabolism and nutrition disorders weight increase	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.	0.00% 0/11 • Data collected over 12 weeks of study.
Cardiac disorders decrease in blood pressure	18.2% 2/11 • Number of events 2 • Data collected over 12 weeks of study.	0.00% 0/11 • Data collected over 12 weeks of study.
Gastrointestinal disorders loose stool	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.	0.00% 0/11 • Data collected over 12 weeks of study.
Cardiac disorders bradycardia	27.3% 3/11 • Number of events 3 • Data collected over 12 weeks of study.	18.2% 2/11 • Number of events 2 • Data collected over 12 weeks of study.
General disorders sore throat	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.	0.00% 0/11 • Data collected over 12 weeks of study.
Respiratory, thoracic and mediastinal disorders URI	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.	0.00% 0/11 • Data collected over 12 weeks of study.
Musculoskeletal and connective tissue disorders tension in muscles	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.	0.00% 0/11 • Data collected over 12 weeks of study.
Cardiac disorders hypotension	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.	0.00% 0/11 • Data collected over 12 weeks of study.
Cardiac disorders elevated heart rate	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.	0.00% 0/11 • Data collected over 12 weeks of study.
General disorders heavy sweating	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.	0.00% 0/11 • Data collected over 12 weeks of study.
Gastrointestinal disorders reduced appetite	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.	0.00% 0/11 • Data collected over 12 weeks of study.
General disorders chest pain	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.
General disorders chills	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.	0.00% 0/11 • Data collected over 12 weeks of study.
Psychiatric disorders depression	0.00% 0/11 • Data collected over 12 weeks of study.	18.2% 2/11 • Number of events 2 • Data collected over 12 weeks of study.
General disorders difficulty with memory	0.00% 0/11 • Data collected over 12 weeks of study.	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.
Gastrointestinal disorders diarrhea	18.2% 2/11 • Number of events 2 • Data collected over 12 weeks of study.	0.00% 0/11 • Data collected over 12 weeks of study.
General disorders dizziness	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.	0.00% 0/11 • Data collected over 12 weeks of study.
General disorders dry mouth	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.	0.00% 0/11 • Data collected over 12 weeks of study.
General disorders fatigue	18.2% 2/11 • Number of events 2 • Data collected over 12 weeks of study.	18.2% 2/11 • Number of events 2 • Data collected over 12 weeks of study.
Gastrointestinal disorders GI upset	18.2% 2/11 • Number of events 2 • Data collected over 12 weeks of study.	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.
General disorders headache	36.4% 4/11 • Number of events 4 • Data collected over 12 weeks of study.	0.00% 0/11 • Data collected over 12 weeks of study.
Cardiac disorders increased bloop pressure	54.5% 6/11 • Number of events 6 • Data collected over 12 weeks of study.	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.
General disorders insomnia	0.00% 0/11 • Data collected over 12 weeks of study.	18.2% 2/11 • Number of events 2 • Data collected over 12 weeks of study.
General disorders loss of libido	0.00% 0/11 • Data collected over 12 weeks of study.	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.
Musculoskeletal and connective tissue disorders muscle aches	18.2% 2/11 • Number of events 2 • Data collected over 12 weeks of study.	0.00% 0/11 • Data collected over 12 weeks of study.
Cardiac disorders orthostasis	0.00% 0/11 • Data collected over 12 weeks of study.	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.
General disorders syncopy/lightheadness	0.00% 0/11 • Data collected over 12 weeks of study.	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.
Psychiatric disorders anxiety	9.1% 1/11 • Number of events 1 • Data collected over 12 weeks of study.	27.3% 3/11 • Number of events 3 • Data collected over 12 weeks of study.