Pilot trial finds guanfacine feasible for cannabis use disorder with significant use reductions

In a small open-label pilot trial, guanfacine extended-release was feasible and well-tolerated for cannabis use disorder, with significant reductions in daily cannabis amount, spending, and use days over 8 weeks.

Dakwar, Elias et al.·The American journal of drug and alcohol abuse·2020·Preliminary EvidencePilot Study
RTHC-02492Pilot StudyPreliminary Evidence2020RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Pilot Study
Evidence
Preliminary Evidence
Sample
N=22

What This Study Found

Among 22 cannabis-dependent individuals, daily cannabis use in grams (p = .004), dollars spent (p < .001), and days of use (p = .007) significantly decreased over the 8-week study. Retention at week 8 was 41%. Three participants achieved 3+ weeks of total abstinence. No significant differences between two titration schedules.

Key Numbers

22 participants; 41% retention at 8 weeks; significant reductions in grams (p = .004), dollars (p < .001), and days of use (p = .007); 3 participants achieved 3+ weeks abstinence.

How They Did This

Eight-week open-label outpatient pilot trial of guanfacine extended-release (G-XR) in 22 cannabis-dependent adults. Two titration schedules tested (gradual to 4 mg or highest tolerated dose). Standard medication management provided.

Why This Research Matters

No approved pharmacotherapy exists for cannabis use disorder. This pilot suggests guanfacine, an alpha-2 adrenergic agonist already approved for ADHD, warrants further study as a potential treatment.

The Bigger Picture

With cannabis use disorder increasing alongside legalization, the absence of effective medications is a major treatment gap. Repurposing existing medications like guanfacine offers a faster path to potential treatments.

What This Study Doesn't Tell Us

Open-label without placebo control; very small sample; 41% retention suggests tolerability challenges; natural reduction over time cannot be excluded.

Questions This Raises

  • ?Would a placebo-controlled trial confirm these reductions?
  • ?Could guanfacine be combined with behavioral interventions for better outcomes?

Trust & Context

Key Stat:
Significant reductions in cannabis use (grams, dollars, days); 41% retention at 8 weeks
Evidence Grade:
Small open-label pilot without placebo control; designed as a feasibility study.
Study Age:
Published in 2020.
Original Title:
Guanfacine extended-release for cannabis use disorder: a pilot feasibility trial.
Published In:
The American journal of drug and alcohol abuse, 46(1), 44-48 (2020)
Database ID:
RTHC-02492

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study

A small preliminary study to test whether a larger study is feasible.

What do these levels mean? →

Frequently Asked Questions

What is guanfacine and why might it help cannabis addiction?

Guanfacine is an alpha-2 adrenergic agonist approved for ADHD and hypertension. It may help cannabis use disorder by reducing withdrawal symptoms and improving behavioral control, which are key challenges in cannabis cessation.

Is this now a treatment for cannabis addiction?

Not yet. This was a small pilot study to test feasibility. The results are promising enough to warrant a larger, placebo-controlled trial to determine if guanfacine truly reduces cannabis use beyond what would happen naturally.

Read More on RethinkTHC

Cite This Study

RTHC-02492·https://rethinkthc.com/research/RTHC-02492

APA

Dakwar, Elias; Mahony, Amy; Choi, C Jean; Pavlicova, Martina; Brooks, Daniel; Mariani, John P; Levin, Frances R. (2020). Guanfacine extended-release for cannabis use disorder: a pilot feasibility trial.. The American journal of drug and alcohol abuse, 46(1), 44-48. https://doi.org/10.1080/00952990.2019.1620259

MLA

Dakwar, Elias, et al. "Guanfacine extended-release for cannabis use disorder: a pilot feasibility trial.." The American journal of drug and alcohol abuse, 2020. https://doi.org/10.1080/00952990.2019.1620259

RethinkTHC

RethinkTHC Research Database. "Guanfacine extended-release for cannabis use disorder: a pil..." RTHC-02492. Retrieved from https://rethinkthc.com/research/dakwar-2020-guanfacine-extendedrelease-for-cannabis

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.