Rifampin and the Contraceptive Implant

• Status: Recruiting
• Trial end date: 2021-12-01
• Target enrollment: 0
• Participant gender: Female

Summary

It is important for women taking rifampin to be aware if they are at greater risk of an unintended pregnancy while on the implant. An unintended pregnancy has many social, emotional, and financial impacts on women and society. Rifampin is also a Class C medication for pregnancy and could have potential negative effects on a developing fetus. Additionally, women considering rifampin for treatment of LTBI face additional risks with an unintended pregnancy, making the reliability of contraception even more important for these women. The results of this study can directly inform counseling on a national and international basis for women who use the contraceptive implant and are considering their treatment options for LTBI.

• Phase: Phase 4
• Accepts Healthy Volunteers?: Accepts Healthy Volunteers

Details

• Lead Sponsor: University of Colorado, Denver
• Collaborator: Merck Sharp & Dohme Corp.
• Treatments: Rifampin

Criteria

Inclusion Criteria:

• Healthy women, who have had an ENG implant for 12-36 months at the time of enrollment and will maintain their implant during the study without modifications.

Exclusion Criteria:

• o Women who are taking any known cytochrome P-450 3A4 enzyme inducers or inhibitors.

• Women with a known allergy or insensitivity to rifampin.

• Women with a body mass index (BMI) <18.5, as underweight women may have altered metabolism. The investigators will not have an upper BMI cut-off as studies have shown that overweight and obese women have equivalent metabolism and efficacy with the ENG contraceptive implant6,7.

• Exclusions Criteria (screening laboratory testing)

• Women with any hepatic or renal dysfunction as determined by a comprehensive metabolic panel. For purposes of this study, liver function tests will be evaluated and evidence of hepatic dysfunction will be defined as an ALT >52 or AST >39, which are beyond the reference range of normal values used by the University of Colorado clinical laboratory. Renal function will be assessed by a serum creatinine and a value >1.2 will be evidence of renal dysfunction as this is greater than the reference range used by the University of Colorado clinical laboratory.

• Women with any abnormal hematology as determined by a complete blood count. For purposes of this study, abnormal hematology will be defined as a WBC, RBC, or PLT value beyond the reference range of normal values used by the University of Colorado clinical laboratory.

• Women with abnormal coagulation factors as determined by coagulation factor tests (PT/INR, PTT). For purposes of this study, abnormal coagulation factors will be defined as any test value beyond the reference range of normal values used by the University of Colorado clinical laboratory.