NCT04596826

The Effect of Dronabinol on Ocular Hemodynamics in Patients With Primary Open Angle Glaucoma

Completed Phase 2 Last updated 16 May 2025

What this trial tests

Phase 2 trial testing Dronabinol 5 MG in Retinal Blood Flow in 51 participants. Completed in 2 October 2024.

Timeline

11 November 2020

Primary endpoint
2 October 2024

2 October 2024

Quick facts

Lead sponsor	Medical University of Vienna
Phase	Phase 2
Status	Completed
Study type	INTERVENTIONAL
Allocation	randomized
Design	crossover
Masking	double
Primary purpose	diagnostic
Enrollment	51
Start date	11 November 2020
Primary completion	2 October 2024
Estimated completion	2 October 2024
Sites	1 location across Austria

Drugs / interventions tested

• Dronabinol 5 MG — full drug profile →
• Dronabinol 10 MG — full drug profile →
• Placebo

Conditions studied

• Retinal Blood Flow — all drugs for Retinal Blood Flow →

Sponsor

Medical University of Vienna

Who can join

18 and older, any sex, with Retinal Blood Flow. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

Glaucoma is among the leading causes for irreversible blindness worldwide. While lowering intraocular pressure (IOP) remains the mainstay of therapy, there are still some patients who progress despite well-controlled IOP. There is evidence from several studies that ocular blood flow and its regulation is impaired in patients with glaucoma. Tetrahydrocannabinol (THC) has been used in the treatment for glaucoma in some countries for several years due to its IOP lowering effect. In addition, there is also evidence that THC features neuroprotective effects and improves ocular hemodynamics. Dronabinol is a synthetic THC that is legally available in several European countries. It has the advantage that exact dosing of THC is possible in contrast to previously applied administration forms such as smoking. Due to its legal status in the past, data about the effect of THC on ocular blood flow and its regulation are sparse. In a recent study conducted in the investigators laboratory they found that single administration of dronabinol leads to a significant increase in optic nerve head (ONH) blood flow without impairing its autoregulatory capacity.The aim of the present study therefore is to investigate whether single administration of dronabinol alters optic nerve head (ONH) blood flow in patients with open angle glaucoma. In addition, other parameters for ocular blood flow will be measured, in particular retinal blood flow, retinal oxygen saturation and retinal neurovascular coupling. The study will be conducted in a parallel-group, randomized, double-masked, placebo-controlled, cross-over design. Patients will be randomized to either receive 5mg or 10mg dronabinol on one study day. Other studies investigating retinal hemodynamics or IOP after administration of THC also have used similar or slightly higher doses.

Publications & conference data

3 peer-reviewed publications reference this trial (live from Europe PMC):

1. Glaucoma Clinical Research: Trends in Treatment Strategies and Drug Development.
   Storgaard L, Tran TL, Freiberg JC, Hauser AS, et al · · 2021 · cited 50× · PMID 34589504 · DOI 10.3389/fmed.2021.733080
2. Challenging glaucoma with emerging therapies: an overview of advancements against the silent thief of sight.
   Sarkis S, Chamard C, Johansen B, Daien V, et al · · 2025 · cited 5× · PMID 40206485 · DOI 10.3389/fmed.2025.1527319
3. Single oral administration of dronabinol increases ocular blood flow in patients with glaucoma.
   Lindner T, Pai V, Janku P, Hommer N, et al · · 2026 · cited 1× · PMID 40772417 · DOI 10.1111/aos.17573