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Completed No phase listed Observational

Study of Tests to Evaluate Effectiveness of Anti-HIV Drugs

ClinicalTrials.gov ID: NCT00006494

Public ClinicalTrials.gov record NCT00006494. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.

ClinicalTrials.gov public records Last synced Sep 21, 2026, 10:39 AM EDT

Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.

Official title

An Assessment of the Relationship Between Antiretroviral Drug Genotype/Phenotype (IC50) and Antiretroviral Activity in HIV-Infected, Drug-Experienced Patients With Suboptimal Suppression of Plasma Viral Load

Brief summary

Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.

The purpose of this study is to determine how laboratory tests called genotyping and phenotyping assess the effectiveness of antiretroviral drugs used to treat HIV infection. Some HIV-infected patients have measurable levels of virus in their blood even though they are taking combination drug therapy-including didanosine, stavudine, or efavirenz-against HIV. Genotyping and phenotyping can be used to test for resistance to a specific drug, thereby providing information that can help doctors decide on optimal drug treatment for a given patient. Genotyping identifies mutations, or changes, the virus undergoes that allow it to continue to grow despite drug treatment. Phenotyping involves growing the virus in test tubes with different amounts of drug and then calculating how much drug is required to stop its growth. Patients 18 years of age and older with HIV infection and viral levels between 5000 and 100,000 copies per milliliter of blood who have been taking antiretroviral therapy for at least 6 months may be eligible for this study. Candidates will be screened with a urine test and various blood tests, including genotyping and phenotyping. Participants will have a series of tests to determine whether or not a drug is active against HIV. This involves temporarily stopping the drug under study (i.e., either efavirenz or didanosine or stavudine). The study procedure is as follows: 1. Patients will have six blood tests over 10 days to measure viral load while on all current anti-HIV medications. On one of those days two blood tests will be done to measure levels of didanosine or stavudine. Efavirenz will also be measured if this drug is to be stopped. 2. The patient will temporarily stop the drug under while continuing to take the other drugs. (Efavirenz will be stopped for 3 weeks; stavudine and didanosine will be stopped for 2 weeks.) Seven blood tests will be done at the following intervals to measure viral load: For patients who stop efavirenz, blood will be drawn on days 13, 18, 20, 22, 24,28 and 30. (Day 0 is the first day of the study.) Patients who stop stavudine or didanosine will have blood drawn on days 11, 13, 15, 17, 19, 22 and 24. Repeat genotype and phenotype testing will also be done during this time, and a CD4 count (measurement of a certain type of white blood cell) will be done at the end of this 2- or 3-week period. 3. The drug that was stopped will be restarted and viral load tests will be repeated. For pati...

Study identification

NCT ID
NCT00006494
Recruitment status
Completed
Study type
Observational
Phase
Not listed
Enrollment
14 participants

Conditions and interventions

Conditions

Interventions

Not listed

Eligibility (public fields only)

Age range
18 Years and older
Sex
All
Healthy volunteers
Healthy volunteers not accepted

This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.

Study timeline

Start date
Nov 6, 2000
Primary completion
Not listed
Completion
Sep 5, 2011
Last update posted
Jul 1, 2017

2000 – 2011

United States locations

U.S. sites
2
U.S. states
1
U.S. cities
1
Facility City State ZIP Site status
National Naval Medical Center Bethesda Maryland 20889
National Institutes of Health Clinical Center, 9000 Rockville Pike Bethesda Maryland 20892

Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.

About this trial record page

What this page shows
Public field values for ClinicalTrials.gov record NCT00006494, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
What this page does not do
No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
Where the data comes from
Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
Last refresh
Last update posted Jul 1, 2017 · Synced Sep 21, 2026

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Open the official record

The complete protocol, eligibility criteria, and contact information for NCT00006494 live on ClinicalTrials.gov.

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