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Effect of Diltiazem Administration on CP-945,598 Pharmacokinetics

This study has been completed.
Information provided by:
Pfizer Identifier:
First received: March 21, 2008
Last updated: September 16, 2009
Last verified: March 2008

A recently completed clinical drug interaction study of CP-945,598 with ketoconazole, a potent CYP3A inhibitor, showed that coadministration of CP-945,598 with ketoconazole results in an approximately 5-fold increase in CP-945,598 total exposure (AUC) and 4-fold increase in Cmax. Therefore, the sensitivity of CP-945,598 pharmacokinetics (PK) to less potent CYP3A inhibitors needs to be characterized to support labeling and registration.

Diltiazem is a known substrate and moderate mechanism-based inhibitor of the CYP3A enzyme system and was chosen as the moderate CYP3A inhibitor for this study as it is a clinically relevant medication likely to be prescribed concomitantly with CP-945,598 given the increased risk of hypertension and cardiovascular disease in the obese patient population.

Condition Intervention Phase
Obesity Drug: CP-945,598 Phase 1

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: A Phase 1, Randomized, Fixed Sequence Study To Evaluate The Effect Of Multiple Dose Administration Of Modified Release Diltiazem On The Multiple Dose Pharmacokinetics Of CP-945,598 In Healthy Overweight And Obese Subjects

Resource links provided by NLM:

Further study details as provided by Pfizer:

Primary Outcome Measures:
  • Pharmacokinetic parameters of CP-945,598 and its metabolite, CE-156,706, (AUCtau, Cmax and Tmax) [ Time Frame: Days 7 and 28 ]
  • Safety endpoints including adverse event monitoring, physical examinations, vital signs, ECGs, and clinical laboratory tests. [ Time Frame: 28 days ]

Enrollment: 28
Study Start Date: March 2007
Study Completion Date: June 2007
Arms Assigned Interventions
Experimental: Group A Drug: CP-945,598
20 mg CP-945,598 + 240 mg MR Diltiazem
Experimental: Group B Drug: CP-945,598
20 mg CP-945,598 alone


Ages Eligible for Study:   18 Years to 55 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • No clinically relevant abnormalities based upon medical history, physical exam, 12-lead ECG, and clinical lab tests
  • Body Mass Index (BMI) ~ 27-40 kg/m2, inclusive
  • Personally signed inform consent document

Exclusion Criteria:

  • Evidence or history of significant acute or chronic disease
  • Pregnant or nursing females
  • Screening PR interval > 220 msec
  • Sitting blood pressure <= 90 mmHg systolic or <= 60 mmHg diastolic
  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: NCT00645463

United States, Michigan
Pfizer Investigational Site
Ann Arbor, Michigan, United States, 48105
Sponsors and Collaborators
Study Director: Pfizer Call Center Pfizer
  More Information

Additional Information:
Responsible Party: Director, Clinical Trial Disclosure Group, Pfizer, Inc. Identifier: NCT00645463     History of Changes
Other Study ID Numbers: A5351043
Study First Received: March 21, 2008
Last Updated: September 16, 2009

Additional relevant MeSH terms:
Antihypertensive Agents
Calcium Channel Blockers
Membrane Transport Modulators
Molecular Mechanisms of Pharmacological Action
Vasodilator Agents processed this record on August 23, 2017