Rifampin and the Contraceptive Implant
Condition: Contraception; Tuberculosis
MeSH terms: Tuberculosis
Intervention: Rifampin 600 MG
Intervention description: Administered daily for 2 weeks
Intervention MeSH terms: Rifampin
Phase: Phase 4
Study type: Interventional
Primary purpose: Basic Science
Intervention model: Single Group Assignment
Masking: None (Open Label)
Enrollment: 24.0
Sex: Female
Minimum age: 18 Years
Maximum age: 45 Years
Healthy volunteers: Accepts Healthy Volunteers

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.
    

Eligibility 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.