Short-term Treatment of Cocaine and/or Methamphetamine Abuse With Vigabatrin

Abstract

To evaluate the ocular safety of short-term use of vigabatrin to treat cocaine and/or methamphetamine addiction. Methods: Individuals who were actively using cocaine and/or methamphetamine were eligible for enrollment. Enrolled subjects were scheduled for comprehensive eye examinations at the beginning and end of the study. Visual field testing was performed at baseline and 1 week, 4 weeks, 8 weeks, and 1 month or more after discontinuing vigabatrin. Twenty-eight subjects received at least 1 dose of vigabatrin; however, only 20 subjects continued beyond the initial escalating vigabatrin dose phase to the treatment phase. Of these 20 subjects, 18 completed the study with full follow-up. Visual fields were evaluated subjectively by 2 glaucoma specialists and analyzed objectively for group and individual changes in quadrant mean sensitivity. The objective analysis was also repeated for superior field quadrants after excluding the uppermost peripheral points to minimize the eyelid effect. The main outcome measures were change of visual field, visual acuity, and ocular adverse effects. Results: Vigabatrin seemed to help treat cocaine and/or methamphetamine addiction. Of 18 subjects, 16 had negative test results for cocaine and methamphetamine use during the last 6 weeks of the trial. No ocular adverse events were detected. The subjective evaluation did not reveal visual field constriction in any of the 18 evaluable participants. Objective group and individual analyses for quadrant mean sensitivity did not show any change from baseline in any quadrant. No changes in visual acuity were noted. Conclusions: In this short-term pilot study, vigabatrin seemed to help treat cocaine and/or methamphetamine abuse. There was no evidence of ocular or visual field adverse effects.

A Multisite, Double-blind, Placebo-Controlled Clinical Trial to Evaluate the Safety and Efficacy of Vigabatrin for Treating Cocaine Dependence

“…With respect to safety, no participants reported any visual disturbance throughout their open-label exposure to vigabatrin, 17 and no changes in vital signs or objective measures of visual fields or visual acuity were found with open-label exposure up to 9 weeks. 18,19 In the placebocontrolled trial, 16 no statistically significant differences were observedbetweenthevigabatringroupandtheplacebogroup for adverse events (AEs), visual abnormalities, or medical conditions.…”

Medication Development for the Treatment of Cocaine Addiction – Progress at Preclinical and Clinical Levels

“…In three open-labeled studies, GVG was well-tolerated and produced a significant increase in cocaine abstinence rate (Brodie et al, 2003(Brodie et al, , 2005Fechtner et al, 2006). In a more recent randomized, double-blind, placeto-controled trial, short-term GVG treatment significantly increased abstinence rate compared to placebo (Brodie et al, 2009).…”

“…However, in another clinical trial for the treatment of methamphetamine dependence, GVG was not effective (De La Garza et al, 2009). GVG is not marketed in the USA because of concerns over ophthalmological side-effects, but none were observed during these short-term studies (Fechtner et al, 2006). More studies are underway to confirm its efficacy for cocaine dependence (http://clinicaltrials.gov).…”

Methamphetamine Addiction: A Review of the Literature

“…No substantial evidence for efficient treatment has yet emerged [81]. Clinical trials using aripiprazole [82,83], GABA agents (gabapentin [84,85], baclofen [84], vigabatrin [86,87]), SSRIs [88][89][90], ondansetron [91,92] and mirtazapine have failed to show efficacy [81]. In a double -blind, placebo-controlled design, naltrexon 50 significantly decreased the subjective effects produced by drugs in dependent patients [94].…”