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Effect Of Rifampin On Pharmacokinetics Of Sitaxsentan

This study has been withdrawn prior to enrollment.
Information provided by:
Pfizer Identifier:
First received: December 1, 2010
Last updated: March 4, 2015
Last verified: January 2011
This study will assess how rifampin will affect the blood levels of sitaxsentan. Safety of sitaxsentan given alone and with rifampin will also be assessed.

Condition Intervention Phase
Pulmonary Arterial Hypertension
Drug: Sitaxsentan alone
Drug: Sitaxsentan
Drug: Rifampin
Phase 1

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Pharmacokinetics Study
Intervention Model: Crossover Assignment
Masking: Open Label
Primary Purpose: Basic Science
Official Title: A Phase 1, Open Label, Fixed Sequence Design, Multiple Dose Study To Assess The Effect Of Rifampin On The Pharmacokinetics Of Sitaxsentan In Healthy Subjects

Resource links provided by NLM:

Further study details as provided by Pfizer:

Primary Outcome Measures:
  • Comparison of Peak Plasma Concentrations of sitaxsentan co-administered with rifampin versus sitaxsentan administered alone. [ Time Frame: 24 hours ] [ Designated as safety issue: No ]
  • Comparison of Area Under the Curve of sitaxsentan co-administered with rifampin versus sitaxsentan administered alone. [ Time Frame: 24 hours ] [ Designated as safety issue: No ]

Enrollment: 0
Study Start Date: December 2010
Estimated Study Completion Date: January 2011
Estimated Primary Completion Date: January 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Sitaxsentan Drug: Sitaxsentan alone
Days 1-5: Sitaxsentan tablet, 100 mg, q24 h (once a day)
Experimental: Sitaxsentan plus Rifampin Drug: Sitaxsentan
Days 6-12: Sitaxsentan tablet, 100 mg, q24h (once a day)
Drug: Rifampin
Days 6-12: Rifampin capsule, 600 mg, q24h (once a day)


Ages Eligible for Study:   21 Years to 55 Years   (Adult)
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Healthy male subjects and/or women of non-child bearing potential.
  • Subjects between the ages of 21 and 55 years, inclusive.
  • Signed informed consent.

Exclusion Criteria:

  • Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurologic, or allergic disease.
  • Has hepatic dysfunction.
  • Has history of excessive alcohol and tobacco use.
  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: NCT01251835

Sponsors and Collaborators
Study Director: Pfizer Call Center Pfizer
  More Information

Additional Information:
Responsible Party: Director, Clinical Trial Disclosure Group, Pfizer, Inc. Identifier: NCT01251835     History of Changes
Other Study ID Numbers: B1321060 
Study First Received: December 1, 2010
Last Updated: March 4, 2015
Health Authority: United States: Food and Drug Administration

Keywords provided by Pfizer:
Drug Interaction

Additional relevant MeSH terms:
Familial Primary Pulmonary Hypertension
Hypertension, Pulmonary
Lung Diseases
Respiratory Tract Diseases
Vascular Diseases
Cardiovascular Diseases
Endothelin Receptor Antagonists
Molecular Mechanisms of Pharmacological Action
Antibiotics, Antitubercular
Antitubercular Agents
Anti-Bacterial Agents
Anti-Infective Agents
Leprostatic Agents
Nucleic Acid Synthesis Inhibitors
Enzyme Inhibitors
Cytochrome P-450 CYP2B6 Inducers
Cytochrome P-450 Enzyme Inducers
Cytochrome P-450 CYP2C8 Inducers
Cytochrome P-450 CYP2C19 Inducers
Cytochrome P-450 CYP2C9 Inducers
Cytochrome P-450 CYP3A Inducers processed this record on October 28, 2016