Effects of Obesity on Pharmacokinetics of the Levonorgestrel Emergency Contraceptive Pill

Study Overview
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Brief Summary
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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: Alterations in these pharmacokinetic parameters of the LNG-EC regimen in obese women affect the primary mechanism of action, which is inhibition of ovulation. 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.

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

Conditions
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Obesity

Intervention / Treatment
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* Drug: Levonorgestrel 1.5mg by mouth once


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Normal weight women<br>Levonorgestrel 1.5mg by mouth once | Drug: Levonorgestrel 1.5mg by mouth once<br>* Levonorgestrel 1.5mg by mouth given on menstrual cycle day 8<br>* Other names: Next Choice One Dose;|
| Obese women<br>Levonorgestrel 1.5mg by mouth once | Drug: Levonorgestrel 1.5mg by mouth once<br>* Levonorgestrel 1.5mg by mouth given on menstrual cycle day 8<br>* Other names: Next Choice One Dose;|
| Extremely obese women<br>Levonorgestrel 1.5mg by mouth once | Drug: Levonorgestrel 1.5mg by mouth once<br>* Levonorgestrel 1.5mg by mouth given on menstrual cycle day 8<br>* Other names: Next Choice One Dose;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Maximum concentration (Cmax) |  | Time 0, 1, 2, 3, 4, 6, 8, 12, 16, 24, 48, 72 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time 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 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Emergency contraception, Levonorgestrel emergency contraception, Obesity