Clinical Trials


Pharmacokinetic Study of Two HIV Protease Inhibitors in Patients

This study has been terminated
( Unexpected adverse event )

University of Oklahoma


Information provided by (Responsible Party)
University of Oklahoma Identifier

First received: January 9, 2007
Last updated: February 5, 2009
Last Verified: February 2009
History of Changes


The objective of this study is to determine the pharmacokinetics of lopinavir, ritonavir, and atazanavir when lopinavir/ritonavir and atazanavir are used in combination.

Condition Intervention Phase
HIV Infection

Drug : atazanavir
Drug : lopinavir/ritonavir
Phase 4

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: The Pharmacokinetics of Lopinavir/Ritonavir in Combination With Atazanavir in HIV-Infected Subjects

Further study details as provided by University of Oklahoma:

Primary Outcome Measures

  • Mean pharmacokinetic parameters (Cmax, Cmin, AUC) for lopinavir, ritonavir, atazanavir [ Time Frame: Day 6, Day 12 or 16, Day 20 ]
Secondary Outcome Measures:
  • Safety (e.g., GI tolerance, lab abnormalities, ECG changes) [ Time Frame: Day 6, Day 12 or Day 16, Day 20 ]

Enrollment: 19
Study Start Date: April 2007
Study Completion Date: September 2008
Estimated Primary Completion Date: October 2007 (Final data collection date for primary outcome measure)

Arms Assigned Interventions
Experimental: Arm A
Subjects on atazanavir/ritonavir will add lopinavir/ritonavir.
Drug: lopinavir/ritonavir

Lopinavir/ritonavir 400 mg/100 mg twice daily on Days 6-16, then 800 mg/200 mg daily on Days 17-21.

Other Name: Kaletra 200 mg/50 mg tablets
Experimental: Arm B
Subjects on lopinavir/ritonavir will add atazanavir.
Drug: atazanavir

Atazanavir 300 mg daily on Days 6-12.

Other Name: Reyataz 300 mg capsules

Detailed Description:

Thirty patients with HIV infection will be enrolled in this open-label, parallel arm pharmacokinetic study. Subjects receiving either lopinavir/ritonavir or atazanavir/ritonavir as part of their antiretroviral therapy will have a pharmacokinetic study performed over 12-20 days to examine whether coadministration of lopinavir and atazanavir alters the pharmacokinetics of either agent. The safety of these agents in combination will also be explored.



Ages Eligible for Study: 18 Years to 60 Years  
Sexes Eligible for Study: All  
Accepts Healthy Volunteers: No  


Inclusion Criteria:

  • HIV-seropositive
  • Currently receiving atazanavir/ritonavir or lopinavir/ritonavir in combination with 2-3 nucleoside RT inhibitors or are antiretroviral treatment-naïve
  • If female, is not of childbearing potential or is of childbearing potential and agrees to use a barrier method of contraception throughout the study

Exclusion Criteria:
  • HIV-1 RNA > 400 copies/mL if currently receiving antiretroviral therapy
  • Concurrent use of CYP450 inhibitors or inducers
  • Concurrent use of P-glycoprotein substrates, inhibitors, or inducers
  • Concurrent use of medications known to interact with ritonavir or atazanavir
  • Presence of a chronic health condition deemed by the investigators to potentially impair lopinavir, ritonavir, or atazanavir pharmacokinetics
  • Presence of conduction abnormalities on electrocardiogram
  • Women who are pregnant or breastfeeding
  • Laboratory Abnormalities at baseline:
    • Aminotransferases > 3x ULN
    • Serum bilirubin > 5x ULN
    • Serum creatinine > 1.5x ULN
    • Hemoglobin concentration < 8.0 g/dL
    • Absolute neutrophil count < 800 cells/μL
    • Platelet count < 50,000 cells/μL

contacts and locations

Contacts and Locations

Choosing to participate in a study is an important personal decision.Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below.For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00420355


United States, Oklahoma
OUHSC General Clinical Research Center
Oklahoma City, Oklahoma, United States, 73104

Sponsors and Collaborators

University of Oklahoma


Principal Investigator: R. Chris Rathbun, Pharm.D. University of Oklahoma
More Information

More Information

Responsible Party: R. Chris Rathbun, Pharm.D., University of Oklahoma Health Sciences Center Identifier: NCT00420355   History of Changes  
Other Study ID Numbers: 12637  
Study First Received: January 9, 2007  
Last Updated: February 5, 2009  

Keywords provided by University of Oklahoma:

antiretroviral therapy
protease inhibitors
drug interactions
HIV infection
acquired immunodeficiency syndrome
Treatment Experienced

Additional relevant MeSH terms:
HIV Infections
Atazanavir Sulfate processed this data on May 29, 2020
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