Co-Administration Of Fosamprenavir With Methadone: A Drug Interaction Study.

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00481182
Recruitment Status : Completed
First Posted : June 1, 2007
Last Update Posted : February 23, 2009
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Brief Summary:
To assess the combined effects of fosamprenavir 700mg BID + ritonavir 100mg BID + standardized dose of methadone, on plasma total and unbound methadone enantiomer pharmacokinetics (PK), opiate pharmacodynamic (PD) measures, and safety. The effect of methadone on plasma amprenavir PK will also be assessed by comparison to historical control data.

Condition or disease Intervention/treatment Phase
Healthy Subjects Drug: fosamprenavir + ritonavir + methadone Phase 1

Study Type : Interventional  (Clinical Trial)
Enrollment : 20 participants
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: A Phase I, Open-Label, 2-Period, Single-Sequence, Drug Interaction Study to Assess Steady-State Plasma Methadone Enantiomer Pharmacokinetics Following Co-Administration of Methadone QD With Fosamprenavir 700mg BID + RTV 100mg BID in Opiate-Dependent, HIV Seronegative, Adult Subjects
Study Start Date : February 2005

Primary Outcome Measures :
  1. Serial blood samples will be collected over 24 hours for measurement of plasma (R-) and (S-) methadone (days 4 and 18) and serum amprenavir concentrations (day 18).

Secondary Outcome Measures :
  1. On study days 4, 11, and 18, opioid effects will be assessed pre-dose, 2 hours, and 6 hours following methadone dosing. Pharmacokinetic and opioid pharmacodynamic parameters will be compared between the two treatments.

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Ages Eligible for Study:   18 Years to 64 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Subject is enrolled in a certified methadone maintenance program for at least 12 weeks prior to Period 1, Day 1.

Subject is receiving methadone = 200mg QD that has remained unchanged for 30 days The subject is male, female and is between the age of 18 and 64 years of age.

A female is eligible to enter and participate if she is of non-childbearing potential or of childbearing potential. If of childbearing potential, females must have a negative serum pregnancy test at Screening, and agree to one of the following:

Complete abstinence from sexual intercourse from 2 weeks prior to administration of the study drug. Sexual intercourse with only vasectomized partner.

Body mass index of 19.00 to 32.00 kg/m2. Willing to refrain from the use of illicit drugs and adhere to other protocol-stated restrictions while participating in the study.

Able to understand and comply with protocol requirements and instructions and is likely to complete the study as planned.

Able to give written informed consent prior to screening.

Exclusion Criteria:

  • Subject has a clinically significant abnormality identified on the screening medical or laboratory evaluation, including 12-lead ECG.

Subject has any preexisting condition which could interfere with the absorption, metabolism, and/or excretion of the study drugs.

Subject currently has or has a history of decompensated liver disease (i.e., ascites, esophageal or rectal varices, hepatic encephalopathy) or current evidence of active hepatitis (AST or ALT > 2.5x ULN).

Subject has evidence of liver impairment at screening (i.e., INR > 1.7, total bilirubin >2.0 mg/dL, albumin <3.5 g/dL).

Subject has inadequate venous access. Subject has a history of any hypersensitivity reaction to any component of FPV, APV, RTV, or to any drug chemically related to FPV, APV, or RTV.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00481182

United States, Maryland
GSK Investigational Site
Baltimore, Maryland, United States, 21287-5554
United States, New York
GSK Investigational Site
Buffalo, New York, United States, 14215-1199
Sponsors and Collaborators
Study Director: GSK Clinical Trials, MD GlaxoSmithKline

Responsible Party: Study Director, GSK Identifier: NCT00481182     History of Changes
Other Study ID Numbers: 102577
First Posted: June 1, 2007    Key Record Dates
Last Update Posted: February 23, 2009
Last Verified: February 2009

Keywords provided by GlaxoSmithKline:

Additional relevant MeSH terms:
HIV Protease Inhibitors
Protease Inhibitors
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action
Anti-HIV Agents
Anti-Retroviral Agents
Antiviral Agents
Anti-Infective Agents
Cytochrome P-450 CYP3A Inhibitors
Cytochrome P-450 Enzyme Inhibitors
Analgesics, Opioid
Central Nervous System Depressants
Physiological Effects of Drugs
Sensory System Agents
Peripheral Nervous System Agents
Antitussive Agents
Respiratory System Agents