Cannabis UsePhase 2NCT05273567
A Trial of Guanfacine-er for Cannabis Use Disorder
A Phase 2 study testing guanfacine-ER in people with Cannabis Use, run by New York State Psychiatric Institute at 1 site in United States.
Trial summary
The primary purpose of this study is to investigate the effect of guanfacine-ER on reductions in cannabis use and explore its effects on impulsivity and withdrawal through a hybrid in-person and virtual trial of treatment-seeking individuals with Cannabis Use Disorder (CUD), and assessing the feasibility of the… Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Cannabis Use
- What is being tested?
- guanfacine-ER
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 22 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Jun 2022to 8 Sep 2023
- Phase
- Phase 2
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Meets DSM-V criteria for a current cannabis use disorder
- Seeking treatment for cannabis use disorder with goal to reduce or stop use
- THC-positive drug screen
- Capable of giving informed consent and complying with study procedures
- Access to internet and devices capable of completing study procedures
- capability of receiving mailed packages for study supplies
Who cannot join
- Lifetime history of DSM-V diagnosis of schizophrenia or schizoaffective disorder
- Current DSM-V criteria for a psychiatric disorder supported by the MINI that in the investigator's judgment is unstable, would be disrupted by the study medication, or is likely to require new pharmacotherapy or psychotherapy during the study period. Individuals who are currently stable on psychotropic medication for at least 2 months may be included if in the investigator's opinion the psychotropic medication is compatible with the study medication (guanfacine-ER). Any medical or psychiatric conditions that in the investigator's judgment would interfere with safe participation in the study will be exclusionary.
- Individuals who meet DSM-V criteria for any moderate to severe substance use disorder other cannabis, caffeine or nicotine use disorders
- Pregnancy, lactation, or failure to use adequate contraceptive method in female patients who are currently engaging in sexual activity that can result in pregnancy
- Legally mandated to participate in a substance use disorder treatment program
- Current or recent history of significant violent or suicidal behavior, risk for suicide or homicide
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- Known history of allergy, intolerance, or hypersensitivity to guanfacine
- Bradycardia (< 50 beats/minute), hypotension (sitting or standing BP < 90/50), or symptoms attributable to hypotension (i.e. lightheadedness or dizziness on standing)
- Individuals currently being treated with the antihypertensive medications, including the class of alpha 2 agonists that have a potential drug-interaction with guanfacine based on adrenergic modulation
- Individuals currently taking medications that may interact adversely with guanfacine and deemed not clinically safe by study physician at consent, such as rifampicin, ketoconazole, St. John's Wort, and amitriptyline.
Trial locations and contacts
1 site in 1 country.
United States1 site
STARS Clinic at Columbia and NYSPI Department of Psychiatry
New York, New York, 10017
About this study
Official title: A Randomized Controlled Trial of Guanfacine-er for Cannabis Use Disorder
The primary purpose of this study is to investigate the effect of guanfacine-ER on reductions in cannabis use and explore its effects on impulsivity and withdrawal through a hybrid in-person and virtual trial of treatment-seeking individuals with Cannabis Use Disorder (CUD), and assessing the feasibility of the virtual components of the study.
Read the detailed description
This will be a 12-week randomized, double-blind, placebo-controlled trial, of guanfacine-ER compared to placebo for CUD. 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 or maximum dose as tolerated through week 4. Patients will be maintained on the medication through week 11. During week 11, they will begin a taper to discontinuation, decreasing the dose of guanfacine by 1mg every 4 days until stopped during the last week of the study (week 12). The primary purpose of this study is therefore to investigate the effect of guanfacine-ER on reductions in cannabis use and explore its effects on impulsivity and withdrawal through a hybrid in person and virtual trial of treatment-seeking individuals with CUD. In light of COVID-19 viral transmission mitigation policies, we will make use of the technological applications of virtual visits, remote administration of urine drug testing and medication, and ecological momentary assessments (EMA) in conjunction with once monthly in person visits to the clinic during weeks 1, 4, 8, 12.
Due to a federally mandated, institution-wide pause in research activities under our Federal Wide Assurance (FWA) the study and all research was paused on June 23, 2023.
Received a interest continuation for participants enrolled when paused and last participant completed on September 8, 2023.
NYSPI institutional approval to proceed with research and data analysis was granted on 02/09/2026.
- Conditions
- Cannabis Use
- Being tested
- guanfacine-ER, Placebo
- Keywords
- cannabis, guanfacine, treatment
- Medical subject headings
- Marijuana Abuse
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
guanfacine-ERDrug
Also called Intuniv-er
guanfacine-er dispensed daily, starting at 1mg and increasing to 4mg/day or the maximum tolerated dose.
PlaceboOther
placebo will be dispensed similar to the active arm.
| Study group | Role | What they receive |
|---|---|---|
| Guanfacine-ER | Experimental | 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. Receives: Drug: guanfacine-ER |
| Placebo | Placebo comparator | Placebo will be taken nightly and titrated and tapered similar to the active arm. Receives: Other: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Cannabis Use as Measured by Ecological Momentary Assessments (EMA).
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.
Measured: 12 weeks of study
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Mar 2022
- Study start1 Jun 2022
- Primary completion8 Sep 2023
- Study completion8 Sep 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Cannabis UseStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 22 participants (actual)
Sponsor and investigators
- Lead sponsor
- New York State Psychiatric Institute
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute on Drug Abuse (NIDA)
- Responsible party
- Principal investigator, Christina Ann Brezing, New York State Psychiatric Institute
- Investigators
- Christina Brezing, MD, Principal investigator, NYSPI
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05273567
- Sponsor's protocol ID
- 8103
- Other IDs
- 1K23DA045080-01A1
- Status last verified
- Jul 2026
- First submitted
- 1 Mar 2022
- Last updated
- 18 Aug 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Individual participant data that underlie the results published in this report (after de-identification) (text, tables, figures)
Study at a glance
From the registry record, last updated by the sponsor on 18 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Randomized Controlled Trial of Guanfacine-er for Cannabis Use Disorder
- ClinicalTrials.gov ID
- NCT05273567
- Acronym / sponsor ID
- 8103
- Conditions
- Cannabis Use
- Keywords
- cannabis, guanfacine, treatment
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 22 participants (actual)
- Lead sponsor
- New York State Psychiatric InstituteUniversity, hospital or other
- Collaborators
- National Institute on Drug Abuse (NIDA)
- Study start
- 1 Jun 2022 (actual)
- Primary completion
- 8 Sep 2023 (actual)
- Study completion
- 8 Sep 2023 (actual)
- First posted
- 10 Mar 2022 (actual)
- Results
- Posted 18 Aug 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The primary purpose of this study is to investigate the effect of guanfacine-ER on reductions in cannabis use and explore its effects on impulsivity and withdrawal through a hybrid in-person and virtual trial of treatment-seeking individuals with Cannabis Use Disorder (CUD), and assessing the feasibility of the virtual components of the study.
Detailed description
This will be a 12-week randomized, double-blind, placebo-controlled trial, of guanfacine-ER compared to placebo for CUD. 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 or maximum dose as tolerated through week 4. Patients will be maintained on the medication through week 11. During week 11, they will begin a taper to discontinuation, decreasing the dose of guanfacine by 1mg every 4 days until stopped during the last week of the study (week 12). The primary purpose of this study is therefore to investigate the effect of guanfacine-ER on reductions in cannabis use and explore its effects on impulsivity and withdrawal through a hybrid in person and virtual trial of treatment-seeking individuals with CUD. In light of COVID-19 viral transmission mitigation policies, we will make use of the technological applications of virtual visits, remote administration of urine drug testing and medication, and ecological momentary assessments (EMA) in conjunction with once monthly in person visits to the clinic during weeks 1, 4, 8, 12.
Due to a federally mandated, institution-wide pause in research activities under our Federal Wide Assurance (FWA) the study and all research was paused on June 23, 2023.
Received a interest continuation for participants enrolled when paused and last participant completed on September 8, 2023.
NYSPI institutional approval to proceed with research and data analysis was granted on 02/09/2026.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Guanfacine-ER | Experimental | Drug: guanfacine-ERParticipants 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. |
| Placebo | Placebo comparator | Other: PlaceboPlacebo will be taken nightly and titrated and tapered similar to the active arm. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Meets DSM-V criteria for a current cannabis use disorder
- Seeking treatment for cannabis use disorder with goal to reduce or stop use
- THC-positive drug screen
- Capable of giving informed consent and complying with study procedures
- Access to internet and devices capable of completing study procedures
Key exclusion criteria (10 listed)
- Lifetime history of DSM-V diagnosis of schizophrenia or schizoaffective disorder
- Current DSM-V criteria for a psychiatric disorder supported by the MINI that in the investigator's judgment is unstable, would be disrupted by the study medication, or is likely to require new pharmacotherapy or psychotherapy during the study period. Individuals who are currently stable on psychotropic medication for at least 2 months may be included if in the investigator's opinion the psychotropic medication is compatible with the study medication (guanfacine-ER). Any medical or psychiatric conditions that in the investigator's judgment would interfere with safe participation in the study will be exclusionary.
- Individuals who meet DSM-V criteria for any moderate to severe substance use disorder other cannabis, caffeine or nicotine use disorders
- Pregnancy, lactation, or failure to use adequate contraceptive method in female patients who are currently engaging in sexual activity that can result in pregnancy
- Legally mandated to participate in a substance use disorder treatment program
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| guanfacine-ERAlso: Intuniv-erguanfacine-er dispensed daily, starting at 1mg and increasing to 4mg/day or the maximum tolerated dose. | Drug | Guanfacine-ER |
| Placeboplacebo will be dispensed similar to the active arm. | Other | Placebo |
Primary outcome
Change in Cannabis Use as Measured by Ecological Momentary Assessments (EMA).
Time frame: 12 weeks of study
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.
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Aug 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: Yes. Individual participant data that underlie the results published in this report (after de-identification) (text, tables, figures)
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Christina Brezing, MD principal investigator
NYSPI
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing guanfacine-ER in people with Cannabis Use, run by New York State Psychiatric Institute at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 18 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 18 Aug 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Cannabis Use as Measured by Ecological Momentary Assessments (EMA). (time frame: 12 weeks of study). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Aug 2026.