Pilot Study of Entacapone for Methamphetamine Abuse

Addiction to methamphetamine is a serious health problem. There are no medications that a doctor can give someone to help them stop using methamphetamine. Entacapone (Comtan©) is a medication that could help people addicted to methamphetamine. This study will see how entacapone works in healthy people who are given methamphetamine. We think that the study drug will be well tolerated, and that it will prevent some of the effects of methamphetamine that make it so addictive. We also want to see how differences in people's genes may cause differences in the ways the study drug and methamphetamine work for them. The study has six total visits. The first visit is for screening. Tests and procedures will make sure it is safe for subjects to participate. The second visit is a familiarization day. Subjects will receive methamphetamine, but no entacapone. This is done to make sure they can tolerate the drug and recognize its effects before being given a second drug on the same day. Subjects will take surveys and computer tests to see how the medications change mood, thinking, and liking the drug. The final four visits are the actual study days. Subjects will be randomly assigned (like the flip of a coin) to the different ways to get either 1) study medication or placebo (placebo contains no active study medication) and then 2) methamphetamine or placebo. Subjects will be in all four groups during the study, which means that each day a subject will get a different group.