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Pharmacokinetics of Implanon in Obese Women

This study has been completed.
University of Washington
Information provided by (Responsible Party):
University of Chicago Identifier:
First received: July 25, 2008
Last updated: September 4, 2013
Last verified: September 2013
Prior studies examining the pharmacokinetics, safety, and efficacy of the new etonogestrel-containing single rod implantable contraceptive device, Implanon, did not include women who exceeded 130% of ideal body weight. Yet, as these women comprise a significant portion of the U.S. population, studies of Implanon in obese women are essential. The proposed study represents an important first step in addressing the lack of data on Implanon in obese women. We aim to examine the pharmacokinetics of Implanon in obese women during the first 6 months of use and to provide data on the acceptability, side effect profile, and ease of insertion, palpation, and removal in these women. We also aim to collect samples for future validation studies of the use of the blood spot (finger-stick blood sample on filter paper) as a method of determining plasma etonogestrel.

Contraception Obesity

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Pharmacokinetics of Implanon in Obese Women

Resource links provided by NLM:

Further study details as provided by University of Chicago:

Primary Outcome Measures:
  • To describe the pharmacokinetic profile of Implanon (etonogestrel) among obese women. [ Time Frame: 6 months ]

Secondary Outcome Measures:
  • To describe ease of insertion and palpation of Implanon among obese women [ Time Frame: 6 months ]
  • To describe bleeding patterns among obese users of Implanon [ Time Frame: 6 months ]
  • To describe the acceptability of Implanon among obese women [ Time Frame: 6 months ]
  • To describe the discontinuation rates, reason for discontinuation, and ease of removal in obese women who discontinue the device before or at the end of the 6 month study period [ Time Frame: 6 months ]
  • To determine whether etonogestrel levels can be obtained from finger-stick blood spots [ Time Frame: 6 months ]

Biospecimen Retention:   Samples With DNA
whole blood, serum, plasma

Enrollment: 18
Study Start Date: July 2008
Study Completion Date: December 2011
Primary Completion Date: August 2009 (Final data collection date for primary outcome measure)
Obese women: women with a body mass index (BMI) >30
Normal weight women: women with a BMI <25


Ages Eligible for Study:   18 Years to 45 Years   (Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
Participants will be recruited from resident and faculty practices at the University of Chicago outpatient facilities and from the University of Chicago clinical trails database of past study participants.

Inclusion Criteria:

  • premenopausal with a uterus and at least one ovary
  • willing and able to sign the informed consent
  • willing to comply with the study protocol and visit schedule
  • have a body mass index of less than 25, or greater than or equal to 30
  • weight stable

Exclusion Criteria:

  • known or suspected pregnancy
  • delivery (vaginal or cesarean) within 4 months of device insertion
  • abortion (first or second trimester) within 4 months of device insertion
  • contraindications to Implanon use
  • hemophilia
  • undiagnosed abnormal genital bleeding
  • hypersensitivity or allergy to any components of Implanon
  • personal or family history of thrombosis or thromboembolic disorders
  • hepatic tumors or active liver disease
  • known or suspected carcinoma of the breast or history of breast cancer
  • more that one cardiovascular risk factor such as hypertension or diabetes
  • known history of PCOS, diabetes, or glucose abnormality
  • present use or use within 2 months of device insertion of a CYP3A4 inducer
  • breastfeeding women
  • use of an investigational drug within 2 months of device insertion
  • use of injectable contraception within 6 months of device insertion
  • planning a pregnancy in the next 12 months
  • known HIV infection
  • smoking over the age of 35
  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: NCT00724438

United States, Illinois
University of Chicago
Chicago, Illinois, United States, 60637
Sponsors and Collaborators
University of Chicago
University of Washington
Principal Investigator: Melissa Gilliam, MD, MPH University of Chicago
Study Director: Sara J Mornar, DO University of Chicago
  More Information

Additional Information:
Responsible Party: University of Chicago Identifier: NCT00724438     History of Changes
Other Study ID Numbers: 15956A
Study First Received: July 25, 2008
Last Updated: September 4, 2013

Keywords provided by University of Chicago:
Blood spots

Additional relevant MeSH terms:
Contraceptive Agents, Female
Contraceptive Agents
Reproductive Control Agents
Physiological Effects of Drugs processed this record on August 16, 2017