The Effect of Topiramate on Etonogestrel Concentrations in Contraceptive Implant Users

Inclusion Criteria:

- Healthy women, who have had an ENG implant for 12-36 months at the time of enrollment;

- Will maintain their implant during the study without modifications.

Exclusion Criteria:

- Women who are taking any medications or supplements known to be

1. Cytochrome P-450 enzyme inducers, inhibitors, or substrates, and

2. are not willing to abstain from any of these medications or supplements during
the entire course of the study.

- Women with liver disease (i.e. hepatitis, fatty liver disease), and

- Women with abnormal liver or renal function, or

- Women with abnormal electrolytes on their screening blood work.