Monoamine Antagonist Therapies for Methamphetamine Abuse Prazosin
Condition: Continuous Methamphetamine Abuse
Intervention: Prazosin
Intervention description: Prazosin or oral placebo given before methamphetamine or iv placebo to determine effects of prazosin on methamphetamine.
Intervention MeSH terms: Prazosin
Phase: Phase 2
Study type: Interventional
Primary purpose: Health Services Research
Intervention model: Single Group Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Enrollment: 24.0
Sex: All
Minimum age: 18 Years
Maximum age: 50 Years
Healthy volunteers: Accepts Healthy Volunteers
Keywords: substance abuse

Summary:

      This protocol will test the safety, effectiveness and the metabolism and action of prazosin
      as a potential therapy for methamphetamine abuse. This will be accomplished by performing a
      series of human laboratory studies. In each of these studies, the safety and effectiveness of
      the test medication (prazosin) in the treatment of methamphetamine effects will be
      determined. The study hypothesis is that prazosin will block the methamphetamine receptor
      function, reducing the reinforcing effects of central nervous system effects in humans.
    

Eligibility criteria:

        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 (<60 bpm); prolonged
             corrected QT interval interval (>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 < 40% as determined in the screening
             echocardiogram.

          -  Body Mass Index >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.