Artikel
The effect of a single sublingual cannabinoid administration on intraocular pressure in patients with glaucoma: A placebo-controlled cross-over study
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Autoren
Veröffentlicht: | 22. September 2004 |
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Gliederung
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Objective
The cannabinoids Δ9-tetrahydrocannabinoid (Δ9-THC) and cannabidiol (CBD) could potentially be useful in the treatment of glaucoma. Δ9-THC has been reported to reduce the intraocular pressure (IOP), but is associated with psychotropic side effects. CBD has neuroprotective actions and does not induce any psychotropic side effects. The purpose of this study was to assess the effect on IOP and the safety of sublingual administration of (1) a low dose of Δ9-THC and (2) CBD.
Methods
A randomised, double blind, placebo-controlled, four way crossover study was conducted at a single centre using cannabis based medicine extracts (CBME) of Δ9-THC and CBD. Six patients with ocular hypertension or early POAG received once per week a single sublingual dose at 8 a.m. of the following: 5mg Δ9-THC, 20mg CBD, 40mg CBD or placebo. The effects on IOP, vital signs, visual acuity and possible psychotropic side effects were assessed over 12 hours.
Results
Compared to placebo, two hours after sublingual administration of 5mg of Δ9-THC, IOP was significantly reduced (p=0.026). Neither dose of CBD reduced the IOP at any time. However, the higher dose of CBD (40mg) produced a transient IOP elevation at four hours after administration (p=0.028). Vital signs and visual acuity were not significantly changed by the CBMEs. One patient experienced a transient mild panic-like reaction from 2 to 6 hours after Δ9-THC administration.
Conclusions
Sublingual administration of 20mg CBD did not reduce the IOP but is well tolerated, whereas 40mg CBD can produce a transient increase in IOP. A single sublingual low dose of Δ9-THC induced a temporary reduction of IOP after two hours. Further pharmacological and experimental studies are necessary to decide upon the significance of CBME in glaucoma therapy.