Monoamine Antagonist Therapies for Methamphetamine Abuse Prazosin

Inclusion Criteria

• Must be between the ages of 18-50 years (inclusive).
• Must be a current methamphetamine user, with self-reported amount of IV use being greater than the total administered in the study.
• Must have recent use confirmed by a urine toxicology screen positive for amphetamines.
• Must not be seeking treatment for methamphetamine abuse/dependence.

Exclusion Criteria

• Ill health (major cardiovascular, renal, endocrine, hepatic disorder, to be determined by history provided by the prospective subject or laboratory evaluation as outlined below).
• Current diagnosis of other drug or alcohol physical dependence (other than nicotine or caffeine).
• History of major organic psychiatric disorder (psychosis, schizophrenia, bipolar, mania) or significant psychiatric symptoms at the time of evaluation for study participation, including suicidal ideation.
• Pregnancy, plans to become pregnant, or fertile women without adequate means of contraception.
• Present or recent use of over-the-counter or prescription psychoactive drug or drug that would have major interaction with drugs to be tested.
• Liver function tests greater than three times normal, blood urea nitrogen and creatinine outside of normal range, or thyroid function tests outside of normal range.
• EKG abnormalities including but not limited to: bradycardia ( 450 msec); Wolff-Parkinson-White syndrome; wide complex tachycardia; 2nd degree, Mobitz type II heart block; 3rd degree heart block; left or right bundle branch block.
• Medical contraindication to or prior serious adverse effects from METH or stimulants (i.e., seizures, cardiac arrest) or medical contraindication to test agents (see risks section). Significant physical or psychiatric illness which might impair the ability to safely complete the study or that might be complicated by the study drugs, including prior seizures (after age 8) or other active neurological disease or clinically significant abnormalities on physical examination or screening laboratory values.
• Current enrollment in a methamphetamine, alcohol, or other drug treatment program or current legal problems relating to METH, alcohol, or other drug use, including awaiting trial or supervision by a parole or probation officer.
• Left ventricular ejection fraction 35 or <18.
• Currently trying to quit METH use.
• History of serious adverse event or hypersensitivity to methamphetamine or other study drugs
• Currently taking any medication (including highly active antiretroviral therapy for HIV) other than over-the-counter nonsteroidal anti-inflammatory medications, topical medications, inhaled asthma therapy, and over-the-counter nonsedating antihistamines.
• Any other condition the PI or staff feels will put the subject at risk for entering the study.