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Effects of Obesity on Pharmacokinetics of the Levonorgestrel Emergency Contraceptive Pill

Pharmacokinetics of the Levonorgestrel-only Emergency Contraception Regimen in Normal-weight, Obese and Extremely Obese Users: a Pilot Study

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT02104609
Enrollment
26
Registered
2014-04-04
Start date
2013-04-30
Completion date
2016-05-31
Last updated
2019-04-18

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Obesity

Keywords

Obesity, Emergency contraception, Levonorgestrel emergency contraception

Brief summary

The purpose of this study is to determine the effects of obesity on the pharmacokinetics of the levonorgestrel (LNG) only emergency contraceptive (EC) regimen and on markers of ovulation Primary hypothesis: 1\) Obese users of LNG-EC have a pharmacokinetic profile that is consistent with a larger volume of distribution of LNG. Secondary hypothesis: 1. Alterations in these pharmacokinetic parameters of the LNG-EC regimen in obese women affect the primary mechanism of action, which is inhibition of ovulation. 2. Obesity may affect other factors that alter levels of LNG, such as sex-hormone binding globulin (SHBG) and albumin, which bind LNG and potentially lowers the amount of free LNG.

Interventions

DRUGLevonorgestrel 1.5mg by mouth once

Levonorgestrel 1.5mg by mouth given on menstrual cycle day 8

Sponsors

Society of Family Planning
CollaboratorOTHER
University of Southern California
Lead SponsorOTHER

Study design

Observational model
COHORT
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
FEMALE
Age
18 Years to 35 Years
Healthy volunteers
Yes

Inclusion criteria

* Women between ages 18-35 years * Regular menstrual cycles (24-35 days) for the past 2 months * Ovulatory at defined by midluteal progesterone level \>3 ng/mL (Day 18-25) * Belongs to one of the following categories: normal weight (BMI = 18.5-24.9 kg/m2), obese (BMI = 30-39.9 kg/m2) or extremely obese (BMI ≥ 40 kg/m2) * Participant has no intention of or desire to conceive (e.g., active attempt to become pregnant or in vitro fertilization) for the duration of the study * Participant agrees to consistently use an effective method of nonhormonal contraception throughout the duration of study, which could include: condoms (male or female) with or without a spermicidal agent, diaphragm or cervical cap with spermicide, non-hormonal intra-uterine devise (IUD), or sterilization. * Able to give informed consent

Exclusion criteria

* • Known renal or liver disease * Known pituitary disorder * Known adrenal disorder * Known thyroid disorder * Use of medication known to alter the cytochrome P450 system * Use of depot-medroxyprogesterone acetate in the previous 6 months or any other hormonal contraceptive in the previous 3 months * Currently breastfeeding * Pregnant * Pregnancy in the prior month * Known allergy to medication * Other specific contraindications to LNG EC

Design outcomes

Primary

MeasureTime frame
Maximum concentration (Cmax)Time 0, 1, 2, 3, 4, 6, 8, 12, 16, 24, 48, 72 hours

Secondary

MeasureTime frame
Time to maximum concentration (Tmax)0, 1, 2, 3, 4, 6, 8, 12, 16, 24, 48, 72 hours
Minimum concentration (Cmin)Time 0, 1, 2, 3, 4, 6, 8, 12, 16, 24, 48, 72 hours
Area under the concentration time-curve (AUC)Time 0, 1, 2, 3, 4, 6, 8, 12, 6, 24, 48, 72 hrs

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026