Varenicline vs Placebo for the Treatment of Methamphetamine Dependence

Study Summary

Methamphetamine (MA) abuse is the fastest growing drug problem in the United States and is responsible for significant public health complications, including HIV infection. As a result effective treatments for MA dependence are urgently needed. There are currently no efficacious medications for MA dependence, although results from preliminary randomized trials of bupropion for MA dependence found bupropion to be more effective than placebo, but only among subgroups of participants, including those with lower frequency of MA use at baseline. A growing body of preclinical and clinical studies suggest that cholinergic mechanisms play an important role in the neurobiology of MA and other stimulant dependence, such as nicotine dependence. Mechanistically, cholinergic medications may alleviate MA-associated cognitive dysfunction, thereby improving outcomes of treatment for MA dependence. Varenicline is a partial agonist at α4β2 nicotinic receptors and a full agonist at α7 nicotinic receptors that has been approved as an anti-cigarette smoking medication. In order to assess the potential efficacy of varenicline for methamphetamine dependence, we will perform a clinical trial to assess if varenicline compared to placebo results in greater: 1. reductions in methamphetamine use; 2. treatment retention;

Primary Outcome

Urine samples, collected thrice weekly, were tested for metabolites of MA using radioimmunoassay. Each subject had a possible of 24 urine drug screens to provide during the 8 weeks of medication. An aggregate measure of urine drug screen results was calculated - the Treatment Effectiveness Score (TES) - which is the average of the sum of MA-free urine specimens provided during the treatment period by participants in each treatment condition.

Conditions Studied

Interventions

• DRUG Placebo
• DRUG Varenicline

Study Locations (1)