The purpose of this study is to determine if there are significant cardiovascular or other interactions between sublingual lobeline and intravenous methamphetamine.

Inclusion Criteria:

• Be between the ages of 18 and 45 years of age
• Be in general good health with a history of methamphetamine (MA) abuse (but not dependence)
• If female and of child bearing potential, agrees to use birth control
• Be able to understand and provide written informed consent
• Have a body mass index between 18 and 30
• Have reported use of (MA) during the past three months without experiencing adverse consequence plus a life time MA or amphetamine use history of at least four occasions of use
• Have a negative drug test (barbiturates, benzodiazepines, amphetamines, opiates, cocaine, cannabinoids, ethanol) at screening and at the time of admission

Exclusion Criteria:

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