Progesterone only pills are utilized as immediate postpartum contraception. Though it is
demonstrated to be safe as contraception, it is known to be less efficacious than other
forms of progestin-only contraception, such as DMPA injections, etonogestrel implant
insertion, or progestin-containing intrauterine devices. This is largely secondary to its
short half-life. Norethindrone acetate is known to have a longer half-life than
norethindrone. Though it is widely used in various gynecologic settings, it has never
been studied as a contraceptive option. The metabolically active component of
norethindrone is norethindrone itself. This study aims to confirm that amounts of
norethindrone are comparable or greater in participants taking 5mg of norethindrone
acetate vs taking 0.35mg norethindrone, thereby demonstrating the ability to prescribe
5mg norethindrone acetate as a safe and efficacious form of contraception.
This is a pilot crossover study that will study the pharmacokinetics of norethindrone vs
norethindrone acetate. 6 subjects will be a part of this study. Three will be assigned to
0.35mg norethindrone as the initial drug and three will be assigned to 5 mg norethindrone
acetate as the initial drug. Starting on day 1-3 of the menstrual cycle, participants
will start taking Drug 1 at 7:30am every morning for Days 1-7. At 8am Day 1-7
participants will present to the the Clinical Research Laboratory at Milton S. Hershey
Medical Center for an 8am blood draw to examine serum norethindrone levels. On Day 8
participants will stop taking the medication. On Day 8 subjects will present to the
Clinical Research Lab and will have an IV placed. Participants will get a pregnancy test
to rule-out pregnancy and then hourly blood draws from 8am to 4pm to examine serum
norethindrone levels. Participants will also fill out a Symptom Diary detailing side
effects and overall satisfaction with the drug.
Additionally, on Days 1 and 21, participants will have serum levels drawn to evaluate
levels of luteinizing hormone, follicle stimulating hormone, estradiol, and progesterone
levels.
Participants will undergo a one month washout. For Cycle 2, the alternate drug will be
administered and monitored in the process as detailed above.
The serum samples will be collected in batches, will be spun down and stored in a -4
degree freezer. Levels of norethindrone in serum samples will be measured.
