Quantifying Drug Adherence and Drug Exposure to Antiretroviral Therapy
| Status: | Active, not recruiting |
|---|---|
| Conditions: | HIV / AIDS |
| Therapuetic Areas: | Immunology / Infectious Diseases |
| Healthy: | No |
| Age Range: | 18 - 89 |
| Updated: | 7/25/2018 |
| Start Date: | December 2013 |
| End Date: | June 2019 |
Quantifying Drug Adherence and Drug Exposure to Antiretroviral Therapy.
The purpose of this study is to evaluate cumulative exposure to tenofovir diphosphate
(TFV-DP) using dried blood spots (DBS) in treated HIV-infected patients who are receiving a
TFV-based regimen. Using DBS will allow the investigators to assess this simple method to
measure drug exposure in the clinical setting. The investigators hypothesize that TFV-DP
levels will be lowest in individuals with a detectable viral load and highest in those with
viral suppression.
(TFV-DP) using dried blood spots (DBS) in treated HIV-infected patients who are receiving a
TFV-based regimen. Using DBS will allow the investigators to assess this simple method to
measure drug exposure in the clinical setting. The investigators hypothesize that TFV-DP
levels will be lowest in individuals with a detectable viral load and highest in those with
viral suppression.
Antiretroviral drug exposure is directly linked to individual host factors which include age,
weight, diet, and genetics. However, the main factor impacting long-term drug exposure is
drug adherence. Adherence is a strong predictor of HIV treatment outcomes, but measuring
adherence is difficult due to the inaccuracy of self-reporting and other commonly used
monitoring methods. To date, no gold standard measure to monitor antiretroviral exposure and
adherence has been applied in clinical practice. Tenofovir (TFV) and its active metabolite,
tenofovir diphosphate (TFV-DP), have distinctive pharmacological characteristics that make
them ideal candidates for drug adherence and exposure monitoring. The long half life (~14-17
days) of TFV-DP in red blood cells (RBC) are properties well suited for monitoring average
dose exposure over time. Based on these, the investigators propose that RBC levels of TFV-DP
are an accurate and precise measure of long-term drug exposure in HIV-infected individuals.
In addition, the investigators aim to quantify TFV-DP in dried blood spots (DBS) as a simple
method to measure drug exposure.
This is an observational, 48-week prospective study of HIV-infected individuals treated with
TFV in which the investigators will compare DBS TFV-DP levels in virologically suppressed vs.
non-suppressed individuals and evaluate the utility of TFV-DP in DBS to predict virologic
failure and also drug toxicity. To accomplish this, the investigators will approach
HIV-infected patients currently taking TFV (which is being prescribed by a primary care
physician) and who present to the clinic for regular HIV care. After informed consent is
obtained, the investigators will collect extra blood samples for DBS TFV-DP and obtain
information on drug adherence. The investigators will also collect extra blood samples for
DBS TFV-DP at each subject's subsequent visit for approximately 3 visits in a 48 week period
of time.
weight, diet, and genetics. However, the main factor impacting long-term drug exposure is
drug adherence. Adherence is a strong predictor of HIV treatment outcomes, but measuring
adherence is difficult due to the inaccuracy of self-reporting and other commonly used
monitoring methods. To date, no gold standard measure to monitor antiretroviral exposure and
adherence has been applied in clinical practice. Tenofovir (TFV) and its active metabolite,
tenofovir diphosphate (TFV-DP), have distinctive pharmacological characteristics that make
them ideal candidates for drug adherence and exposure monitoring. The long half life (~14-17
days) of TFV-DP in red blood cells (RBC) are properties well suited for monitoring average
dose exposure over time. Based on these, the investigators propose that RBC levels of TFV-DP
are an accurate and precise measure of long-term drug exposure in HIV-infected individuals.
In addition, the investigators aim to quantify TFV-DP in dried blood spots (DBS) as a simple
method to measure drug exposure.
This is an observational, 48-week prospective study of HIV-infected individuals treated with
TFV in which the investigators will compare DBS TFV-DP levels in virologically suppressed vs.
non-suppressed individuals and evaluate the utility of TFV-DP in DBS to predict virologic
failure and also drug toxicity. To accomplish this, the investigators will approach
HIV-infected patients currently taking TFV (which is being prescribed by a primary care
physician) and who present to the clinic for regular HIV care. After informed consent is
obtained, the investigators will collect extra blood samples for DBS TFV-DP and obtain
information on drug adherence. The investigators will also collect extra blood samples for
DBS TFV-DP at each subject's subsequent visit for approximately 3 visits in a 48 week period
of time.
Inclusion Criteria:
- HIV-infected individual.
- 18 years and older.
- Taking tenofovir.
- Blood drawn during regular clinic visit.
Exclusion Criteria:
- Refusal to participate.
We found this trial at
1
site
13001 E 17th Pl
Aurora, Colorado 80045
Aurora, Colorado 80045
(303) 724-5000
Principal Investigator: Jose R. Castillo-Mancilla, MD
University of Colorado Anschutz Medical Campus Located in the Denver metro area near the Rocky...
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