Pharmacokinetics and Pharmacodynamics of the Etonogestrel Contraceptive Implant When Co-administered With Efavirenz
![]() |
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. |
ClinicalTrials.gov Identifier: NCT01980342 |
Recruitment Status
:
Active, not recruiting
First Posted
: November 8, 2013
Last Update Posted
: November 1, 2016
|
- Study Details
- Tabular View
- Results Submitted
- Disclaimer
- How to Read a Study Record
Condition or disease | Intervention/treatment | Phase |
---|---|---|
Drug Interaction | Drug: Efavirenz | Phase 4 |
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 18 participants |
Intervention Model: | Single Group Assignment |
Masking: | None (Open Label) |
Primary Purpose: | Other |
Official Title: | Pharmacokinetics and Pharmacodynamics of the Etonogestrel Contraceptive Implant When Co-administered With Efavirenz |
Study Start Date : | October 2014 |
Estimated Primary Completion Date : | June 2017 |
Estimated Study Completion Date : | August 2017 |

Arm | Intervention/treatment |
---|---|
Experimental: Efavirenz
Healthy, reproductive-age women using the etonogestrel contraceptive implant who will take a two-week course of efavirenz 400 mg orally each night.
|
Drug: Efavirenz
Healthy women who are using Nexplanon will be asked to take a 2-week course of reduced-dose efavirenz (400 mg daily).
Other Name: Sustiva
|
- Serum concentration of etonogestrel before and after two weeks of efavirenz [ Time Frame: 6 weeks ]We will draw a baseline serum etonogestrel immediately prior to a participant starting the 2-week course of efavirenz. Serial blood samples will subsequently be drawn over the next 6 weeks to assess for changes in serum etonogestrel concentration. We will be looking to see if the serum etonogestrel concentration decreases below the level necessary for reliable ovulation suppression.
- Serum efavirenz concentrations at the start and end of the 2-week dosing period [ Time Frame: 2 weeks ]We will assess serum efavirenz concentrations at the beginning and end of the 2-week dosing period. By comparing these concentrations to historical controls, we will determine whether taking efavirenz while using the etonogestrel implant alters the serum concentration of efavirenz.
- Serum hormone markers of ovulation [ Time Frame: 6 weeks ]We will test serial blood samples for levels of luteinizing hormone (LH), follicle stimulating hormone (FSH), estradiol, and progesterone to determine whether the etonogestrel implant is able to suppress ovulation during and after a course of efavirenz.
- Transvaginal ultrasound to assess for ovarian follicular development [ Time Frame: 6 weeks ]For the entire 6 week period of the study, participants will undergo twice-weekly transvaginal ultrasound to assess for the development of ovarian follicles. This direct assessment of follicular development will be combined with serum hormone concentrations to determine if efavirenz increases the incidence of ovulation in women using the etonogestrel implant for contraception.
- Cervical mucus quality [ Time Frame: 6 weeks ]Cervical mucus quality will be assessed twice weekly throughout the study period. The etonogestrel implant exerts a secondary contraceptive effect by causing cervical mucus to become thick and sticky, and therefore less permissive to the movement of sperm through the female genital tract. We will assess whether efavirenz causes a change in cervical mucus quality that would make sperm penetration more likely, and therefore indicate a reduction in the implant's contraceptive effect.

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, Learn About Clinical Studies.
Ages Eligible for Study: | 18 Years to 40 Years (Adult) |
Sexes Eligible for Study: | Female |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
- Healthy women aged 18-40 years who have a Nexplanon®/Implanon® in place that is palpable on exam, had the device placed between 12 and 24 months prior to enrollment, and can provide documentation of when the implant was placed
- Able to speak and read English
- Documented HIV-negative status within 30 days of enrollment
- BMI between 18.5 and 24.9 kg/m2
- Willingness to take a two-week course of efavirenz
- Willingness to comply with study visit schedule (as described below), including blood sampling, transvaginal ultrasounds, and cervical mucus assessment
- Negative urine human chorionic gonadotropin pregnancy test at study entry
-
Normal laboratory values within 30 days of study entry, as specified below:
- White blood cell count ≥ 4500 and ≤ 11000 cells/mm3
- Platelet count ≥ 100,000 platelets/mm3
- Hemoglobin ≥ 8.0 g/dL
- International normalized ratio (INR) ≤ 1.8
- Aspartate transaminase (SGOT) and alanine aminotransferase (SGPT) ≤ 3 times the upper limit of normal (ULN) (upper limit of normal)
- Creatinine ≤ 1.5 x ULN
- Serum amylase ≤ 1.5 x ULN
- Total bilirubin ≤ 2.0 x ULN
-
Agree to use an additional reliable method of contraception while participating in the study. Acceptable methods include:
- Abstinence
- Condoms (male or female) with or without spermicide
- Pre-existing sterilization of subject or her male partner
- Willingness to abstain from alcohol consumption during the study period
- Willingness to abstain from any grapefruit product or supplement for the duration of the study.
Exclusion Criteria:
- Breastfeeding
- Hypersensitivity to efavirenz
- History of seizure disorder
- Initiated, discontinued, or changed doses of drugs that are cytochrome P450 isoenzyme 3A4 (CYP3A4) inducers or inhibitors within 30 days of study entry.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01980342
United States, Maryland | |
Johns Hopkins University Bayview Medical Center | |
Baltimore, Maryland, United States, 21224 |
Responsible Party: | Jennifer Robinson, Assistant Professor, Johns Hopkins University |
ClinicalTrials.gov Identifier: | NCT01980342 History of Changes |
Other Study ID Numbers: |
NA_00087585 |
First Posted: | November 8, 2013 Key Record Dates |
Last Update Posted: | November 1, 2016 |
Last Verified: | October 2016 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Keywords provided by Jennifer Robinson, Johns Hopkins University:
Long acting reversible contraception HIV |
Additional relevant MeSH terms:
Contraceptive Agents Etonogestrel Efavirenz Reproductive Control Agents Physiological Effects of Drugs Reverse Transcriptase Inhibitors Nucleic Acid Synthesis Inhibitors Enzyme Inhibitors Molecular Mechanisms of Pharmacological Action Anti-Retroviral Agents |
Antiviral Agents Anti-Infective Agents Cytochrome P-450 CYP2C9 Inhibitors Cytochrome P-450 Enzyme Inhibitors Cytochrome P-450 CYP2C19 Inhibitors Cytochrome P-450 CYP2B6 Inducers Cytochrome P-450 Enzyme Inducers Cytochrome P-450 CYP3A Inducers Contraceptive Agents, Female |