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A Study of Continuous Oral Contraceptives and Doxycycline

A Study of Continuous Oral Contraceptives and Doxycycline

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT00480532
Enrollment
131
Registered
2007-05-31
Start date
2007-05-31
Completion date
2011-05-31
Last updated
2014-10-22

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

Conditions

Contraceptives, Oral

Keywords

birth control, continuous contraception, break-through bleeding

Brief summary

The purpose of this study is to learn if the study drug, doxycycline, can decrease the amount of unplanned vaginal bleeding that women commonly experience when taking combined oral contraception (COC)- pills with estrogen and progestin - in a continuous fashion - no hormone-free week. The study drug, doxycycline, is an antibiotic used commonly for many conditions (i.e. acne, Chlamydia infections, pneumonia) and can be safely used on a daily basis. Doxycycline has been shown to decrease unplanned vaginal bleeding in progestin-only contraception but has not been studied in combined hormonal contraception.

Detailed description

We intend to conduct a prospective, randomized, placebo controlled, double blind study at Oregon Health and Science University. This study will be conducted over four 28-day cycles (112 days of active COC hormone). All women enrolled in the study will take the same daily low dose COC. This protocol will be divided into two studies, a bleeding study and an endometrial biopsy study, each with two treatment arms; typical dose doxycycline (Arm 1), and controlled release subantimicrobial dose doxycycline (CRSD)(Arm 2). The first arm (Arm 1) of this study will constitute the typical dose doxycycline arm. In this arm, there will be two study groups. Group 1, the treatment group, will take doxycycline 100 mg orally twice a day for five days starting on the first day of bleeding if breakthrough bleeding occurs. The control group will take a placebo orally twice a day for five days starting on the first day of bleeding if breakthrough bleeding occurs. After three months, both groups will stop doxycycline (or placebo) and will continue on a COC alone for the remaining 28 days of the study. The second arm (Arm 2) of the study will constitute the controlled release subantimicrobial dose doxycycline (CRSD doxycycline)arm. Subjects in this arm of the study will be divided into Group 3 and Group 4. Group 3 will take CRSD doxycycline (40mg) daily for three months. Group 4 will take a daily placebo. Similarly to the first arm of the trial, after three months, both groups will stop doxycycline (or placebo) and will continue in a COC alone for the remaining 28 days of the study. This study also includes a endometrial biopsy sub-study: At the time of recruitment we will identify participants who are willing to undergo endometrial biopsy during the study period. These subjects will constitute a separate cohort who will enroll in the prospective, randomized, double blind, placebo controlled endometrial biopsy study.

Interventions

DRUGLybrel

All women enrolled in the study will take the same daily low dose oral contraceptive (20-mcg EE/90 mcg LNG) dosed in a continuous fashion.

DRUGDoxycycline

100 mg orally twice a day for five days starting on the first day of breakthrough bleeding. This regimen will be repeated if bleeding persists or recurs seven days after completing five-day course of doxycycline.

DRUGOracea

40-mg tablet daily for 84 days

DRUGPlacebo

Placebo pill orally twice a day for five days starting on the first day of breakthrough bleeding. This regimen will be repeated if bleeding persists or recurs seven days after completing five-day course of placebo

DRUGDoxycycline 100bid x5 days at the time of bleeding

Doxycycline 100 mg orally twice a day for five days starting on the first day of breakthrough bleeding. This regimen will be repeated if bleeding persists or recurs seven days after completing five-day course of doxycycline

DRUGSubantimicrobial doxycycline daily

Subantimicrobial dose doxycycline 40mg daily for the first 84 days of the study

Placebo daily for the first 84 days of the study

Sponsors

Oregon Health and Science University
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender
FEMALE
Age
18 Years to 45 Years
Healthy volunteers
Yes

Inclusion criteria

* General good health * Willing and able to agree to randomization and sign informed consent * Currently having regular menstrual cycles (24-36 days), with combined cyclic hormonal method (COCs, Nuva Ring, Ortho Evra), without intermenstrual bleeding in last 2 years.

Exclusion criteria

* Intrauterine device (IUD) in place * Abnormal pap smear that has not been treated or followed up * Those with hypersensitivity reactions to doxycycline or any of the tetracyclines * Use of depomedroxyprogesterone acetate within 9 months of the start of the study. * Use of hormonal medications (excluding cyclic contraceptives and plan B) within 2 months of the start of the study. * Any one unwilling to keep a daily menstrual diary or otherwise unwilling to follow the study criteria * Currently taking medications that interfere with COCs (rifampin, carbamazepine, St. Johns wort) * Currently has a progestin implant * Positive Gonorrhea or Chlamydia cultures at enrollment examination * Smoking more than 5 cigarettes per month * Any medical condition that is a contraindication to the use of COCs in accordance with product labeling including: * History of thrombophlebitis, deep venous thrombosis, thrombogenic vasculopathies, thrombogenic rhythm disorders or thromboembolic disorders * Current or past history of cerebrovascular or coronary artery disease * Scheduled major surgery in the next six months with prolonged immobilization * Diabetes with vascular involvement * Headache with focal neurologic symptoms * Uncontrolled hypertension * Suspected or known carcinoma of the breast or personal history of breast cancer * Carcinoma of the endometrium or other known or suspected estrogen dependent neoplasms * Undiagnosed genital bleeding * History of cholestatic jaundice of pregnancy or cholestatic jaundice with prior oral contraceptive use * Hepatic adenoma or carcinoma or active liver disease if liver function has not returned to normal * Known or suspected pregnancy * Hypersensitivity to estrogen or progesterone containing products

Design outcomes

Primary

MeasureTime frameDescription
Differences in Bleeding Patterns Between Study Groups.The outcome was also assessed for day 1 to 84number of days of bleeding and spotting, self reported on calendar

Secondary

MeasureTime frameDescription
Subject Satisfaction.Assessed on day 112 of the study (the end of the study period). This outcome does not represent a change from baseline. It was assessed at the end of the study period.measured using 100 mm visual analog scale. anchors of not at all satisfied (0mm) extremely satisfied (100mm)
Subject ComplianceAssessed on day 112 of the study (the end of the study period). The outcome reflects the number of subjects who did not miss pills during the entire 112 day study. It does not represent a change from baseline.measured by self report of pill intake on daily diary (yes/no), and reported as percentage with no missed pills over entire study

Countries

United States

Participant flow

Recruitment details

Recruitment at Oregon Health and Science University (OHSU) and University of Hawaii (UH

Participants by arm

ArmCount
Placebo (Treatment)
Placebo (for treatment portion of the study)
33
Doxy (7 Day Treatment Arm)
Doxycycline 100 mg po bid x 7 days taken when bleeding occurred
33
Placebo (Prevention)
Placebo for prevention portion of the study
33
Subantibmicrobial Dose Doxy
Doxycycline 40mg (sustained release) once daily for 84 days
32
Total131

Withdrawals & dropouts

PeriodReasonFG000FG001FG002FG003
Overall StudyProtocol Violation0010
Overall StudyWithdrawal by Subject2431

Baseline characteristics

CharacteristicDoxy (7 Day Treatment Arm)Placebo (Prevention)Placebo (Treatment)Subantibmicrobial Dose DoxyTotal
Age, Categorical
<=18 years
0 Participants0 Participants0 Participants1 Participants1 Participants
Age, Categorical
>=65 years
0 Participants0 Participants0 Participants0 Participants0 Participants
Age, Categorical
Between 18 and 65 years
33 Participants33 Participants33 Participants31 Participants130 Participants
Age, Continuous27.5 years
STANDARD_DEVIATION 6.8
27.8 years
STANDARD_DEVIATION 5.4
28.0 years
STANDARD_DEVIATION 6.6
28.6 years
STANDARD_DEVIATION 6.1
28.0 years
STANDARD_DEVIATION 7
Region of Enrollment
United States
33 participants33 participants33 participants32 participants131 participants
Sex: Female, Male
Female
33 Participants33 Participants33 Participants32 Participants131 Participants
Sex: Female, Male
Male
0 Participants0 Participants0 Participants0 Participants0 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
EG002
affected / at risk
EG003
affected / at risk
deaths
Total, all-cause mortality
— / —— / —— / —— / —
other
Total, other adverse events
0 / 330 / 330 / 320 / 32
serious
Total, serious adverse events
0 / 330 / 330 / 320 / 32

Outcome results

Primary

Differences in Bleeding Patterns Between Study Groups.

number of days of bleeding and spotting, self reported on calendar

Time frame: The outcome was also assessed for day 1 to 84

Population: All participants analyzed in the groups to which they were randomized except for 1 subject in prevention placebo group who was erroneously enrolled although she did not meet enrollment entry criteria

ArmMeasureValue (MEAN)Dispersion
Placebo (Treatment)Differences in Bleeding Patterns Between Study Groups.26.72 daysStandard Error 4.89
Doxy (7 Day Treatment Arm)Differences in Bleeding Patterns Between Study Groups.31.86 daysStandard Error 5.08
Placebo (Prevention)Differences in Bleeding Patterns Between Study Groups.25.69 daysStandard Error 3.24
Subantibmicrobial Dose DoxyDifferences in Bleeding Patterns Between Study Groups.18.84 daysStandard Error 3.3
Secondary

Subject Compliance

measured by self report of pill intake on daily diary (yes/no), and reported as percentage with no missed pills over entire study

Time frame: Assessed on day 112 of the study (the end of the study period). The outcome reflects the number of subjects who did not miss pills during the entire 112 day study. It does not represent a change from baseline.

ArmMeasureValue (NUMBER)
Placebo (Treatment)Subject Compliance25 number of participants with no missed pi
Doxy (7 Day Treatment Arm)Subject Compliance21 number of participants with no missed pi
Placebo (Prevention)Subject Compliance19 number of participants with no missed pi
Subantibmicrobial Dose DoxySubject Compliance20 number of participants with no missed pi
Secondary

Subject Satisfaction.

measured using 100 mm visual analog scale. anchors of not at all satisfied (0mm) extremely satisfied (100mm)

Time frame: Assessed on day 112 of the study (the end of the study period). This outcome does not represent a change from baseline. It was assessed at the end of the study period.

ArmMeasureValue (MEAN)Dispersion
Placebo (Treatment)Subject Satisfaction.63.9 mmStandard Deviation 41.1
Doxy (7 Day Treatment Arm)Subject Satisfaction.64.2 mmStandard Deviation 33
Placebo (Prevention)Subject Satisfaction.72.0 mmStandard Deviation 30.9
Subantibmicrobial Dose DoxySubject Satisfaction.67.0 mmStandard Deviation 35.3

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